Research ArticleA Comparative Study of Partial Replacement ofWheat Flour with Whey and Soy Protein onRheological Properties of Dough and Cookie Quality
Xiaozhi Tang and Junfei Liu
College of Food Science and EngineeringCollaborative Innovation Center for Modern Grain Circulation and SafetyKey Laboratory ofGrains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing 210023 China
Correspondence should be addressed to Xiaozhi Tang warmtxz163com
Received 3 January 2017 Revised 31 March 2017 Accepted 12 April 2017 Published 11 May 2017
Academic Editor Susana Fiszman
Copyright copy 2017 Xiaozhi Tang and Junfei LiuThis is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited
The development of wheat-based foods that are enriched with proteins is increasingly popular The purpose of this study was tocompare the effects of partial replacement of wheat flourwithwhey and soy proteins (0ndash30) on the rheological properties of doughand cookie-making quality The incorporation of whey protein (WP) diluted the concentration of gluten leading to an increase indough development time (MDT) and breakdown torque and a decrease in stability time (MST) and minimum torque (MMT)The gelation of WP during the heat treatment increased dough peak torque (MPT) 1198661015840 and 11986610158401015840 As a contrast the addition of soyprotein (SP) increased dough MST MDT and MMTThe aggregation of SP helped increase 1198661015840 and decrease tan 120575 of the dough inoscillatory shear tests The weak gelling effects and higher water absorption of SP decreased MPT 1198661015840 and 11986610158401015840 of the dough duringheat treatment With SP the spread ratio of cookies first decreased from 639 to 566 and then increased to 686 and the overallacceptability scores ranged from 662 to 702 indicating that the formed soy protein network helped maintain the dough structurefor obtaining an improvement in the quality of bakery products
1 Introduction
Currently with increasing concern regarding the nutritionand flavor of food products the development of wheat-based bakery foods that are enriched with foreign proteinadditives is increasingly popular [1] Whey proteins are thebest quality proteins available and have high digestibilityand a complete amino acid profile Whey proteins are alsorecommended due to their beneficial effects on enhancingimmunity and reducing the risk of heart disease and theincidence of cancer [2] Soybean contains the highest qualityand quantity protein of any other plant sources and isan inexpensive source of protein and calories for humanconsumption and in addition it is seen as a low cost substitutefor milk proteins in developing countries [3] Soy proteinsare also reported having beneficial effects on nutrition andhealth such as prevention of cancer diabetes and obesity andprotection against bowel and kidney diseases Both whey and
soy proteins are the most used proteins in protein fortifiedfood products
There were several reports of the effect of whey or soyproteins on the properties of wheat dough and wheat-basedbakery products [3ndash8] Since it is known that the glutennetwork is responsible for viscoelastic properties in wheatdough and for dough structure strength and gas retentionmost studies above reported that the incorporation of foreignproteins interfered with gluten development and thereforehad negative effects on baking products especially whenamount of foreign proteins was higher than 5 Althoughinitially the aim of addition of proteins was to increase thenutritional value of wheat-based bakery products whey andsoy proteins exhibit various functional properties includingsolubility gelation viscosity emulsifying action moistureholding capacity and foam-stabilizing activity which mightsignificantly impact the structure of the dough and thequality of the some types of products [5 9 10] For example
HindawiJournal of Food QualityVolume 2017 Article ID 2618020 10 pageshttpsdoiorg10115520172618020
2 Journal of Food Quality
the ability of whey proteins to thicken and form a gelupon heating might be advantageous for some applicationshowever this ability might also be disadvantageous for others[11] Therefore the selection of the protein source withappropriate functionality might play an important role incertain application In addition if a continuous protein phasecould be created when amount of foreign proteins was higherthan gluten in wheat flour they might confer a protectiveeffect on dough structure for obtaining an improvement inthe quality of bakery products
Therefore the objective of this study was to compare theeffect of whey and soy protein addition on the thermome-chanical dynamic rheological andmicrostructural propertiesof wheat dough and the cookie-making quality A relativelywide range of foreign protein addition (0ndash30) to wheatdough was tested Such a study is essential for product devel-opment and process control when considering the popularityof protein fortified bakery products
2 Materials and Methods
21 Materials Wheat flour was obtained from ShenzhenSouthseas Grains Industries Ltd (Shenzhen China) whichcontained protein of 853 fat of 115 ash of 028(dry weight basis) and 1209 moisture Whey proteinwas purchased from Fonterra Co-operative Group Limited(Aucklan New Zealand) It contains 7644 protein and669 moisture Soy protein was obtained from Yihai KerryGroups (Qinhuangdao China) with 8658 protein and681 moisture Whey and soy proteins were mixed withwheat flour at seven substitution levels (0 5 10 1520 25 and 30) for further tests
22 Mixolab Measurements The thermomechanical charac-teristics of the samples were determined using a Mixolab(Chopin Paris France) For the assays a certain amountof wheat-protein blends with known moisture content wasplaced into the Mixolab bowl and mixed to obtain doughof 75 g After tempering the solids the water required forthe dough to produce a torque of 11 Nm was automaticallyadded by the Mixolab system The settings used in the testwere as follows (1) the temperature was kept constant at 30∘Cfor 8min (2) then the temperature was raised to 90∘C at arate of 4∘Cmin holding for 7min (3) the temperature wascooled to 50∘Cat a rate of 4∘Cmin holding for another 5minThe mixing speed during the entire analysis was 80 rpmTheprocesses were repeated three times for each sample
The following parameters were obtained from Mixo-lab measurements [12] Mixolab water absorption (MWA)Mixolab development time (MDT) Mixolab stability time(MST) Mixolab minimum torque (MMT) Protein weaken-ing (PW) Pasting temperature (PT) Mixolab peak torque(MPT) Mixolab breakdown torque (MBD) Mixolab setbacktorque (MSB)
23 Dough Stickiness Dough stickiness (DS) was deter-mined with a Texture Analyzer (TA-XT2i Stable MicroSystems Godalming UK) using a Chen and Hoseney cell
[13] The settings were as follows compression force 40 gplexiglass probe diameter 25mm trigger force 5 g pretestspeed 2mms posttest speed 10mms holding time 01 s andprobe travel distance 4mmThe force required for separatingthe probe from the dough surface was recorded Triplicatemeasurements were performed
24 Rheological Measurements The dynamic rheologicalproperties of the dough were determined using a controlled-stress rheometer (MCR 302 Anton Paar Austria) The plate-plate geometry was used with a diameter of 50mm and agap between plates of 1mm Assayed doughs were previouslyprepared using Mixolab when the torque reached 11 Nm Oilwas used to prevent the samples drying during tests A resttime of 15min was applied to all samples before measuringThree replicates of each measurement were made
Stress sweep tests at 10Hz were firstly conducted in orderto define the linear viscoelasticity zone in the range of strainfrom 001 to 1 frequency sweep tests were performedin the range of 1 to 100 rads at a strain value of 01 todetermine the storage modulus (1198661015840) loss modulus (11986610158401015840) andtan 120575 (119866101584010158401198661015840)
The temperature sweep tests were then performed at astrain of 01 and frequency of 1Hz Dough was heated inthe rheometer cell from 30 to 90∘C at 5∘Cmin The storagemodulus (1198661015840) and the loss modulus (11986610158401015840) were recorded as afunction of temperature
25 Scanning Electron Microscopy Themicrostructure of thedough was observed by scanning electron microscopy Forthe assay the samples were fixed in 3 glutaraldehyde for 2 hand embedded in a graded ethanol series (30 50 70and 90) for 20min at each gradation After that sampleswere embedded in 100 ethanol for three consecutive 20minintervals to ensure full dehydration and then freeze-driedFragments of the freeze-dried samples were mounted onaluminium specimen stubs using doubled tape and sputter-coated with a layer of gold by Ion Sputter Sample analysiswas performed at an accelerating voltage of 15 kV with SEM(TM3000 Hitachi Japan)
26 Cookie Preparation and Quality Evaluation Cookieswere prepared according to AACC 10ndash50119863 The diameter(119863) thickness (119879) and spread ratio (119863119879) were determinedaccording to AACC standard method 10ndash50119863 [14] Thehardness of cookies was determined using three-point break(HDP3 PB) technique with a Texture Analyzer (TA-XT2iStable Micro Systems Godalming UK) The pretest speedwas set at 30mms test speed at 10mms and posttest speedat 100mms Probe travel distance was set at 10mm and dataacquisition rate at 500 ppsThemaximum breaking force wasrecorded which could be referred to as the hardness of thecookies Seven replicates were performed for each test Thecolor was measured as a series of 119871lowast 119886lowast and 119887lowast values bycolorimeter (KonicaMinolta Japan) Each assaywas repeated10 times and the average value was used Color difference(Δ119864) was defined as the difference between samples and
Journal of Food Quality 3
Table 1 Effect of whey and soy protein addition on thermomechanical properties and stickiness of wheat dougha
MWA()
MDT(min)
MST(min)
MMT(Nm)
PW(Nm)
PT(∘C)
MPT(Nm)
MBD(Nm)
MSB(Nm)
DS(g)
Control 538 112 plusmn007ab
762 plusmn028c 050 plusmn 0e 063 plusmn001e
5560 plusmn026a
221 plusmn003c
042 plusmn002a
167 plusmn001c
2337 plusmn964a
Whey protein
5 498 266 plusmn039c
463 plusmn008ab 030 plusmn 0c 080 plusmn 0g 5825 plusmn035bc
228 plusmn001c
059 plusmn003ab 09 plusmn 003
a 4476 plusmn1231b
10 471 335 plusmn004c
376 plusmn095a
024 plusmn001b
082 plusmn001gh
5830 plusmn099bc 23 plusmn 001
c 063 plusmn 0bc 089 plusmn003a6531 plusmn2349c
15 442 413 plusmn008d
375 plusmn004a 023 plusmn 0b 085 plusmn 0h 6020 plusmn071cd 249 plusmn 0d 084 plusmn001c 08 plusmn 005
a 11231 plusmn354d
20 432 442 plusmn002d
366 plusmn008a
020 plusmn001b 089 plusmn 0i 6060 plusmn028cd
275 plusmn001e
126 plusmn014d 08 plusmn 015a 13698 plusmn1166e
25 430 428 plusmn022d
423 plusmn018a 011 plusmn 0a 097 plusmn002j
6220 plusmn041d
284 plusmn006e
193 plusmn001e
093 plusmn002a
13157 plusmn1793e
30 427 422 plusmn035d
526 plusmn023ab
012 plusmn001a
097 plusmn002j
6180 plusmn071d
305 plusmn004f
231 plusmn006f
099 plusmn006a
14271 plusmn996e
Soy protein
5 588 081 plusmn011a
590 plusmn029b
043 plusmn001d
067 plusmn001f
5673 plusmn057ab
200 plusmn001b
055 plusmn001ab
140 plusmn002b
1917 plusmn593a
10 651 153 plusmn010b
840 plusmn091cd 050 plusmn 0e 061 plusmn002de
5723 plusmn075ab
177 plusmn001a
070 plusmn004bc
144 plusmn004b
1599 plusmn314a
15 720 161 plusmn003b
899 plusmn015cde
055 plusmn001f
058 plusmn002d mdash mdash mdash mdash 1535 plusmn
359a
20 793 167 plusmn018b
983 plusmn034de
058 plusmn001f
053 plusmn001c mdash mdash mdash mdash 1698 plusmn
293a
25 870 163 plusmn006b
1001 plusmn013e
062 plusmn003g
048 plusmn002b mdash mdash mdash mdash 1480 plusmn
168a
30 944 163 plusmn022b
1047 plusmn054e
066 plusmn001h
044 plusmn001a mdash mdash mdash mdash 1377 plusmn
266aaData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different119901 le 005
standardwhite porcelain on color whichwas calculated usingthe following equation
Δ119864 = radic(119871lowast minus 119871 119904)2 + (119886lowast minus 119886119904)2 + (119887lowast minus 119887119904)2 (1)
where 119871 119904 119886119904 and 119887119904 are values of standard white porcelain9713 021 and 187 respectively and 119871lowast 119886lowast and 119887lowast are thedetermined values of cookies
27 Consumer Acceptability Test The consumer acceptabilitystudy was carried out in the Sensory Evaluation AnalysisLaboratory of College of Food Science and Engineeringat Nanjing University of Finance and Economics NanjingChina A consumer panel consisting of 50 subjects wasrecruited to rate cookies on their overall acceptability andother attributes All panelists were cookie consumers A 9-point hedonic scale (1 = ldquodislike extremelyrdquo 5 = ldquoneither likenor dislikerdquo and 9= ldquolike extremelyrdquo)was used to evaluate theproducts Cookies were rated for overall acceptability accept-ability of hardness texturemouth feel colorappearance andflavor Cookies with an overall acceptability score above 5were considered as acceptable The cookies were prepared 1day prior to testing and stored at room temperature in sealedplastic bags All the samples were randomized using 3-digit
codes The order of the treatments served to the consumerswas also random Drinking water was used to cleanse mouthbetween the samples
28 Statistical Analysis Statistical analysis of the data wasperformed usingOrigin 90 (OriginLabCorp NorthamptonMA) Statistical significance of differences in means was cal-culated using ANOVA and Bonferronirsquos multiple comparisontests at 119901 lt 005
3 Results and Discussion
31 MixolabMeasurements Mixolab allows the characteriza-tion of the physicochemical behavior of protein and starch indough when subjected to dual mechanical shear and temper-ature constraints (Table 1)Whey protein (WP) incorporation(0sim30) decreased MWA of wheat dough from 538 to427 Indrani et al [5] also reported that the substitutionof wheat flour with WP decreased water absorption As thesubstitution level of WP increased from 0 to 20 MDTincreased and MST decreased However as the WP level wasfurther increased to 30 no significant changes forMDT butMST increased from 366 to 526min Dough development
4 Journal of Food Quality
time (MDT) and stability time (MST) are indicators of flourstrength with higher values suggesting stronger dough inwhich wheat gluten plays a critical role in the formation ofa three-dimensional viscoelastic structure [15] The additionof WP led to a complex system and delayed the hydrationand stretching and alignment of the wheat gluten leading tothe increase of MDT MST decreased due to the dilution ofwheat gluten and WP interference with the gluten networkZadow [16] reported that wheat flour dough weakening byWP is due to interference by WP sulfhydryl groups of thenormal sulfhydryldisulfide interchange reaction that occursduring wheat flour dough development At concentrationgreater than 20 the addition of WP significantly increaseddough stickiness (DS Table 1) and subsequently increasedMST Dough MMT reflects a weakening of wheat proteinThe addition of WP diluted the concentration of gluten anddestroyed the continuous state of the wheat flour doughrendering it difficult to form a stable gluten network structureunder the double effects ofmechanical force and heating thusMMT continued to decrease and PW continued to increase
During the heating stage starch granules absorb wateravailable in the medium and swell Amylose chains leachout into the aqueous intergranular phase promoting anincrease in viscosity and leading to peak in torque Withincreasing WP PT also significantly increased WP additiondecreased dough water absorption At the same time WP isexpected to compete for water with the primary starch chainsduring heating and this might cause the observed pastingtemperature to increase [17] MPT significantly increasedpossibly due to WP gelation Marco and Rosell [18] reportedthat the thermally induced gelation of the proteins developedduring the heat treatment which greatlymodified rheologicalbehaviors of the dough WP forms viscoelastic gels uponheating above its denaturation temperature [19]
In response to the addition of WP MBD increasedindicating that the addition of WP reduced the thermalstability of the starch in doughThe addition ofWP destroyedthe continuous gluten network structure and subsequentlyweakening its protective effect on starch subjected to amylaseAs the substitution level of WP increased MSB of thedough first decreased and then increased MSB might havedecreased because the proportion of starch decreased Athigher WP concentrations the strengthening of the WP gelduring the cooling stage might have caused the rise again inMSB
Compared to WP wheat flour-soy protein (SP) doughexhibited different behaviors in Mixolab measurements Theincorporation of SP (0sim30) increased MWA from 538to 944 in wheat flour dough MDT MST and MMTfirst decreased at 5 substitution level and then continuallyincreased with the further increase of SP level from 5 to30 The increase of above parameters in the presence ofSP was attributed to the aggregation of SP and its higherwater binding capacity in the dough system which increasedthe mechanical tolerance of the dough [9 20] However inthe heating stage no Mixolab data were obtained when SPsubstitution level was higher than 10 This was probablybecause of higher percentage of water absorption by SP Thedough could not hold the water under the double effects of
mechanical shear and heating The Mixolab mechanical armskidded in the process of mixing therefore the instrumentcould not detect the torque value From the existing data itwas observed that MPT significantly decreased with increas-ing level of SP possibly due to lower content of starch andhigher amount of water in the dough
32 Dough Stickiness Stickiness (DS) ofwhey and soy proteinenriched wheat flour dough was also shown in Table 1With increasing WP content the stickiness of the doughincreased from 2337 to 14271 g whereas the stickiness of thedough with addition of soy protein decreased from 2337 to1377 g Dough stickiness is caused by an interactive balancebetween adhesion and cohesion [21] Adhesion represents theinteraction between amaterial (dough) and a surface (probe)whereas cohesion describes the interactions inside the dough[22] In wheat flour gluten absorbed water to induce proteininteractions that play a critical role in dough stickiness [23]As the WP content increased the hydration of WP resultedin higher surface adhesion which played a leading role in theincrease of dough stickiness However in wheat-SP doughdilution of gluten and higher percentage of water led to asharp decrease of dough stickiness
33 Rheological Measurements The rheological properties ofWP and SP enriched wheat flour dough were studied usinga controlled-stress rheometer and the results were shown inFigure 1 The storage modulus (1198661015840) is a measure of the solidor elastic character of the dough and the loss modulus (11986610158401015840)is a measure of the liquid or viscous character tan 120575 (119866101584010158401198661015840)indicates the relative contributions of the viscous and elasticcharacteristics of the dough Figure 1 showed that that 1198661015840and 11986610158401015840 decreased and tan 120575 increased with increasing WPproportion in wheat doughs indicating a weakened glutennetwork However 1198661015840 increased and 11986610158401015840 and tan 120575 decreasedwith increasing SP proportion in wheat doughs potentiallydue to soy protein aggregation within the medium It wasreported that SP can increase disulphide linkage providingelasticity for baked goods [9 18] The results were also con-sistent with the rheological measurements taken by MixolabThe addition of WP softened the dough system due to theinterference with the gluten network [6] while soy proteinenhanced stability and elasticity of the dough
All protein enriched wheat doughs demonstrated anincrease in storage and loss modulus with increase in fre-quency (Figure 1) However the addition of WP increasedthe frequency dependence as indicated by the increase of thetan 120575 slope compared to that of wheat dough control (Fig-ure 1(b)) All dough samples showed a soft gel-like viscoelasticbehavior with 1198661015840 higher than 11986610158401015840 except the dough with 30WP substitution which showed a crossover at 158 rads Thiscrossover was associated with a change in the viscoelasticbehavior suggesting that the viscous component becamemore relevant than elastic one when frequency was higherthan 158 rads
Temperature sweep of doughs with different WP and SPsubstitution levels was shown in Figure 2 During the teststhree distinct stages of dynamic rheological changes were
Journal of Food Quality 5
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
103
104
G㰀㰀
(Pa)
103
104
G㰀
(Pa)
(a)
0102030
tan 훿
1 10 100
Angular frequency (rads)
04
08
12
tan훿
(b)
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀
(Pa)
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀㰀
(Pa)
(c)
0102030
tan 훿
1 10 100
Angular frequency (rads)
021
024
027
030
033
tan훿
(d)
Figure 1 The effect of whey and soy protein addition on 1198661015840 11986610158401015840 and tan 120575 of wheat dough with frequency sweep WP ((a) (b)) SP ((c) (d))
observed For wheat dough the first stage was observed from30∘C to 54∘C As the temperature increased the values of1198661015840 and 11986610158401015840 decreased slightly possibly due to hydrolysis ofdamaged starch by amylaseThe second stage was observed attemperatures above 54∘C At this stage 1198661015840 increased rapidlyand reached a maximum value at 72∘C indicating the gela-tinization of starch During gelatinization amylose chainsleached out into the aqueous intergranular phase increasingdough viscosity and elasticity [24] At the third stage starchgelatinization was complete and1198661015840 and11986610158401015840 began to decreasebecause of starch degradation Upon the addition of WPthe transition temperature and the temperature at which themaximum value of 1198661015840 and 11986610158401015840 was observed were clearlydelayed and dependent on the amount of WP added Theincrease in transition temperature was consistent with the
results obtained using Mixolab which indicated that WPwould compete forwaterwith the starch and glutenmoleculesin the dough system The peak value of 1198661015840 and 11986610158401015840 of thedough significantly increased with the increasing level ofWPfrom 0 to 20 and slightly decreased with further increaseof WP level to 30 The heat-induced gelation of WP wasmainly responsible for the increase of1198661015840 and11986610158401015840 In additionheat treatment of WP changes its structure from the nativecompact folded to a denatured unfolded structure [6]There-fore the sites for cross-linking among proteins and starchesincrease with an increase in protein concentration whichwill subsequently affect the properties of the dough It wasreported that WPcassava starch composite gels containingup to 20 cassava starch in the system showed enhancedviscoelastic properties as compared to gels made from either
6 Journal of Food Quality
8460 724836
Temperature (∘C)
010
2030
103
104
105
G㰀
(Pa)
(a)
103
104
105
G㰀㰀
(Pa)
8460 724836
Temperature (∘C)
010
2030
(b)
8460 724836
Temperature (∘C)
104
105
G㰀
(Pa)
010
2030
(c)
8460 724836
Temperature (∘C)
104
105
G㰀㰀
(Pa)
010
2030
(d)
Figure 2 The effect of whey and soy protein addition on 1198661015840 and 11986610158401015840 of wheat dough with temperature sweep WP ((a) (b)) SP ((c) (d))
component alone meaning synergistic interactions betweenWP and starch [25] Compared to WP wheat-SP doughfollowed quite similar tendencies of 1198661015840 and 11986610158401015840 as wheatdough control The transition temperature was at 54∘C andthe temperature for the maximum value of 1198661015840 and 11986610158401015840 wasat 72∘C However 1198661015840 and 11986610158401015840 decreased with the increasingconcentration of SP because of decreased starch content ofthe dough and higher water absorption and weaker gellingeffect of SP
34 Scanning Electron Microscopy The microstructure ofwheat flour dough as influenced by the substitution of 10and 30 of WP and SP is presented in Figure 3 Micrographof wheat dough is shown in Figure 3(a) The figure presentedthat the dough had a relatively smooth surface and starchgranules were embedded in the gluten matrix To compare
the effects ofWP and SP enrichment it was clearly seen fromFigures 3(b) and 3(c) that starch granules were still partlyembedded in the protein matrix due to the surface adhesioninduced by WP However hollows or ditches were observedon the dough surface indicating that the continuity of thegluten matrix had been disrupted by WP With the additionof 10 SP (Figure 3(d)) it could be seen that starch granuleswere separated from the protein matrix meaning disruptionin the well-defined protein-starch complex of wheat flourdough However the protein matrix composed of glutenand SP seemed more compact beyond fragmented areasprobably due to previously mentioned aggregation of SP andits higher water binding capacity With the addition of 30SP (Figure 3(e)) the aggregation of SP induced formation ofsoy protein network which provided a protective effect onstarch-protein complex thus leading to higher stability andelasticity of the dough
Journal of Food Quality 7
N D107 times500 200 um
(a)N times500 200 umD9
(b)
N times500 200 umD104
(c)N times500 200 umD91
(d)
N times500 200 umD98
(e)
Figure 3 Scanning electron micrographs of dough with different percentage substitution of WP and SP (a) Control (b) Control + 10WP(c) Control + 30WP (d) Control + 10 SP (e) Control + 30 SP
35 Cookie Quality Characteristics Table 2 showed the effectof substitution of wheat flour with WP and SP on the qualityparameters of cookies Usually higher spread ratio is con-sidered as one of the desirable quality attributes [26] Fromthe results the spread ratio of cookies continually decreasedfrom639 to 400with the increase ofWP content Differentlythe incorporation of SP decreased the cookie spread ratiofrom 639 to 566 and then increased to 686 The resultsabove based on SP enrichment were not in agreement withprevious studies [27ndash29] who reported a decrease in spreadratio of cookies with increase in proteins and concluded thatthe incorporation of foreign proteins interfered with gluten
development and therefore had negative effects on bakingproducts especially when amount of foreign proteins washigher than 5However things were different when amountof SP was higher than gluten content The aggregation ofSP induced formation of soy protein network which helpedincrease the elasticity and extensibility of the wheat doughthus leading to increased spread ratio The soy proteinnetworkmight also confer a protective effect on partial glutenstructure for obtaining an improvement in the quality ofbakery products The results were consistent with Mixolabmeasurements which showed that both MMT and MST firstdecreased and then increasedwith the further increasing level
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
2 Journal of Food Quality
the ability of whey proteins to thicken and form a gelupon heating might be advantageous for some applicationshowever this ability might also be disadvantageous for others[11] Therefore the selection of the protein source withappropriate functionality might play an important role incertain application In addition if a continuous protein phasecould be created when amount of foreign proteins was higherthan gluten in wheat flour they might confer a protectiveeffect on dough structure for obtaining an improvement inthe quality of bakery products
Therefore the objective of this study was to compare theeffect of whey and soy protein addition on the thermome-chanical dynamic rheological andmicrostructural propertiesof wheat dough and the cookie-making quality A relativelywide range of foreign protein addition (0ndash30) to wheatdough was tested Such a study is essential for product devel-opment and process control when considering the popularityof protein fortified bakery products
2 Materials and Methods
21 Materials Wheat flour was obtained from ShenzhenSouthseas Grains Industries Ltd (Shenzhen China) whichcontained protein of 853 fat of 115 ash of 028(dry weight basis) and 1209 moisture Whey proteinwas purchased from Fonterra Co-operative Group Limited(Aucklan New Zealand) It contains 7644 protein and669 moisture Soy protein was obtained from Yihai KerryGroups (Qinhuangdao China) with 8658 protein and681 moisture Whey and soy proteins were mixed withwheat flour at seven substitution levels (0 5 10 1520 25 and 30) for further tests
22 Mixolab Measurements The thermomechanical charac-teristics of the samples were determined using a Mixolab(Chopin Paris France) For the assays a certain amountof wheat-protein blends with known moisture content wasplaced into the Mixolab bowl and mixed to obtain doughof 75 g After tempering the solids the water required forthe dough to produce a torque of 11 Nm was automaticallyadded by the Mixolab system The settings used in the testwere as follows (1) the temperature was kept constant at 30∘Cfor 8min (2) then the temperature was raised to 90∘C at arate of 4∘Cmin holding for 7min (3) the temperature wascooled to 50∘Cat a rate of 4∘Cmin holding for another 5minThe mixing speed during the entire analysis was 80 rpmTheprocesses were repeated three times for each sample
The following parameters were obtained from Mixo-lab measurements [12] Mixolab water absorption (MWA)Mixolab development time (MDT) Mixolab stability time(MST) Mixolab minimum torque (MMT) Protein weaken-ing (PW) Pasting temperature (PT) Mixolab peak torque(MPT) Mixolab breakdown torque (MBD) Mixolab setbacktorque (MSB)
23 Dough Stickiness Dough stickiness (DS) was deter-mined with a Texture Analyzer (TA-XT2i Stable MicroSystems Godalming UK) using a Chen and Hoseney cell
[13] The settings were as follows compression force 40 gplexiglass probe diameter 25mm trigger force 5 g pretestspeed 2mms posttest speed 10mms holding time 01 s andprobe travel distance 4mmThe force required for separatingthe probe from the dough surface was recorded Triplicatemeasurements were performed
24 Rheological Measurements The dynamic rheologicalproperties of the dough were determined using a controlled-stress rheometer (MCR 302 Anton Paar Austria) The plate-plate geometry was used with a diameter of 50mm and agap between plates of 1mm Assayed doughs were previouslyprepared using Mixolab when the torque reached 11 Nm Oilwas used to prevent the samples drying during tests A resttime of 15min was applied to all samples before measuringThree replicates of each measurement were made
Stress sweep tests at 10Hz were firstly conducted in orderto define the linear viscoelasticity zone in the range of strainfrom 001 to 1 frequency sweep tests were performedin the range of 1 to 100 rads at a strain value of 01 todetermine the storage modulus (1198661015840) loss modulus (11986610158401015840) andtan 120575 (119866101584010158401198661015840)
The temperature sweep tests were then performed at astrain of 01 and frequency of 1Hz Dough was heated inthe rheometer cell from 30 to 90∘C at 5∘Cmin The storagemodulus (1198661015840) and the loss modulus (11986610158401015840) were recorded as afunction of temperature
25 Scanning Electron Microscopy Themicrostructure of thedough was observed by scanning electron microscopy Forthe assay the samples were fixed in 3 glutaraldehyde for 2 hand embedded in a graded ethanol series (30 50 70and 90) for 20min at each gradation After that sampleswere embedded in 100 ethanol for three consecutive 20minintervals to ensure full dehydration and then freeze-driedFragments of the freeze-dried samples were mounted onaluminium specimen stubs using doubled tape and sputter-coated with a layer of gold by Ion Sputter Sample analysiswas performed at an accelerating voltage of 15 kV with SEM(TM3000 Hitachi Japan)
26 Cookie Preparation and Quality Evaluation Cookieswere prepared according to AACC 10ndash50119863 The diameter(119863) thickness (119879) and spread ratio (119863119879) were determinedaccording to AACC standard method 10ndash50119863 [14] Thehardness of cookies was determined using three-point break(HDP3 PB) technique with a Texture Analyzer (TA-XT2iStable Micro Systems Godalming UK) The pretest speedwas set at 30mms test speed at 10mms and posttest speedat 100mms Probe travel distance was set at 10mm and dataacquisition rate at 500 ppsThemaximum breaking force wasrecorded which could be referred to as the hardness of thecookies Seven replicates were performed for each test Thecolor was measured as a series of 119871lowast 119886lowast and 119887lowast values bycolorimeter (KonicaMinolta Japan) Each assaywas repeated10 times and the average value was used Color difference(Δ119864) was defined as the difference between samples and
Journal of Food Quality 3
Table 1 Effect of whey and soy protein addition on thermomechanical properties and stickiness of wheat dougha
MWA()
MDT(min)
MST(min)
MMT(Nm)
PW(Nm)
PT(∘C)
MPT(Nm)
MBD(Nm)
MSB(Nm)
DS(g)
Control 538 112 plusmn007ab
762 plusmn028c 050 plusmn 0e 063 plusmn001e
5560 plusmn026a
221 plusmn003c
042 plusmn002a
167 plusmn001c
2337 plusmn964a
Whey protein
5 498 266 plusmn039c
463 plusmn008ab 030 plusmn 0c 080 plusmn 0g 5825 plusmn035bc
228 plusmn001c
059 plusmn003ab 09 plusmn 003
a 4476 plusmn1231b
10 471 335 plusmn004c
376 plusmn095a
024 plusmn001b
082 plusmn001gh
5830 plusmn099bc 23 plusmn 001
c 063 plusmn 0bc 089 plusmn003a6531 plusmn2349c
15 442 413 plusmn008d
375 plusmn004a 023 plusmn 0b 085 plusmn 0h 6020 plusmn071cd 249 plusmn 0d 084 plusmn001c 08 plusmn 005
a 11231 plusmn354d
20 432 442 plusmn002d
366 plusmn008a
020 plusmn001b 089 plusmn 0i 6060 plusmn028cd
275 plusmn001e
126 plusmn014d 08 plusmn 015a 13698 plusmn1166e
25 430 428 plusmn022d
423 plusmn018a 011 plusmn 0a 097 plusmn002j
6220 plusmn041d
284 plusmn006e
193 plusmn001e
093 plusmn002a
13157 plusmn1793e
30 427 422 plusmn035d
526 plusmn023ab
012 plusmn001a
097 plusmn002j
6180 plusmn071d
305 plusmn004f
231 plusmn006f
099 plusmn006a
14271 plusmn996e
Soy protein
5 588 081 plusmn011a
590 plusmn029b
043 plusmn001d
067 plusmn001f
5673 plusmn057ab
200 plusmn001b
055 plusmn001ab
140 plusmn002b
1917 plusmn593a
10 651 153 plusmn010b
840 plusmn091cd 050 plusmn 0e 061 plusmn002de
5723 plusmn075ab
177 plusmn001a
070 plusmn004bc
144 plusmn004b
1599 plusmn314a
15 720 161 plusmn003b
899 plusmn015cde
055 plusmn001f
058 plusmn002d mdash mdash mdash mdash 1535 plusmn
359a
20 793 167 plusmn018b
983 plusmn034de
058 plusmn001f
053 plusmn001c mdash mdash mdash mdash 1698 plusmn
293a
25 870 163 plusmn006b
1001 plusmn013e
062 plusmn003g
048 plusmn002b mdash mdash mdash mdash 1480 plusmn
168a
30 944 163 plusmn022b
1047 plusmn054e
066 plusmn001h
044 plusmn001a mdash mdash mdash mdash 1377 plusmn
266aaData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different119901 le 005
standardwhite porcelain on color whichwas calculated usingthe following equation
Δ119864 = radic(119871lowast minus 119871 119904)2 + (119886lowast minus 119886119904)2 + (119887lowast minus 119887119904)2 (1)
where 119871 119904 119886119904 and 119887119904 are values of standard white porcelain9713 021 and 187 respectively and 119871lowast 119886lowast and 119887lowast are thedetermined values of cookies
27 Consumer Acceptability Test The consumer acceptabilitystudy was carried out in the Sensory Evaluation AnalysisLaboratory of College of Food Science and Engineeringat Nanjing University of Finance and Economics NanjingChina A consumer panel consisting of 50 subjects wasrecruited to rate cookies on their overall acceptability andother attributes All panelists were cookie consumers A 9-point hedonic scale (1 = ldquodislike extremelyrdquo 5 = ldquoneither likenor dislikerdquo and 9= ldquolike extremelyrdquo)was used to evaluate theproducts Cookies were rated for overall acceptability accept-ability of hardness texturemouth feel colorappearance andflavor Cookies with an overall acceptability score above 5were considered as acceptable The cookies were prepared 1day prior to testing and stored at room temperature in sealedplastic bags All the samples were randomized using 3-digit
codes The order of the treatments served to the consumerswas also random Drinking water was used to cleanse mouthbetween the samples
28 Statistical Analysis Statistical analysis of the data wasperformed usingOrigin 90 (OriginLabCorp NorthamptonMA) Statistical significance of differences in means was cal-culated using ANOVA and Bonferronirsquos multiple comparisontests at 119901 lt 005
3 Results and Discussion
31 MixolabMeasurements Mixolab allows the characteriza-tion of the physicochemical behavior of protein and starch indough when subjected to dual mechanical shear and temper-ature constraints (Table 1)Whey protein (WP) incorporation(0sim30) decreased MWA of wheat dough from 538 to427 Indrani et al [5] also reported that the substitutionof wheat flour with WP decreased water absorption As thesubstitution level of WP increased from 0 to 20 MDTincreased and MST decreased However as the WP level wasfurther increased to 30 no significant changes forMDT butMST increased from 366 to 526min Dough development
4 Journal of Food Quality
time (MDT) and stability time (MST) are indicators of flourstrength with higher values suggesting stronger dough inwhich wheat gluten plays a critical role in the formation ofa three-dimensional viscoelastic structure [15] The additionof WP led to a complex system and delayed the hydrationand stretching and alignment of the wheat gluten leading tothe increase of MDT MST decreased due to the dilution ofwheat gluten and WP interference with the gluten networkZadow [16] reported that wheat flour dough weakening byWP is due to interference by WP sulfhydryl groups of thenormal sulfhydryldisulfide interchange reaction that occursduring wheat flour dough development At concentrationgreater than 20 the addition of WP significantly increaseddough stickiness (DS Table 1) and subsequently increasedMST Dough MMT reflects a weakening of wheat proteinThe addition of WP diluted the concentration of gluten anddestroyed the continuous state of the wheat flour doughrendering it difficult to form a stable gluten network structureunder the double effects ofmechanical force and heating thusMMT continued to decrease and PW continued to increase
During the heating stage starch granules absorb wateravailable in the medium and swell Amylose chains leachout into the aqueous intergranular phase promoting anincrease in viscosity and leading to peak in torque Withincreasing WP PT also significantly increased WP additiondecreased dough water absorption At the same time WP isexpected to compete for water with the primary starch chainsduring heating and this might cause the observed pastingtemperature to increase [17] MPT significantly increasedpossibly due to WP gelation Marco and Rosell [18] reportedthat the thermally induced gelation of the proteins developedduring the heat treatment which greatlymodified rheologicalbehaviors of the dough WP forms viscoelastic gels uponheating above its denaturation temperature [19]
In response to the addition of WP MBD increasedindicating that the addition of WP reduced the thermalstability of the starch in doughThe addition ofWP destroyedthe continuous gluten network structure and subsequentlyweakening its protective effect on starch subjected to amylaseAs the substitution level of WP increased MSB of thedough first decreased and then increased MSB might havedecreased because the proportion of starch decreased Athigher WP concentrations the strengthening of the WP gelduring the cooling stage might have caused the rise again inMSB
Compared to WP wheat flour-soy protein (SP) doughexhibited different behaviors in Mixolab measurements Theincorporation of SP (0sim30) increased MWA from 538to 944 in wheat flour dough MDT MST and MMTfirst decreased at 5 substitution level and then continuallyincreased with the further increase of SP level from 5 to30 The increase of above parameters in the presence ofSP was attributed to the aggregation of SP and its higherwater binding capacity in the dough system which increasedthe mechanical tolerance of the dough [9 20] However inthe heating stage no Mixolab data were obtained when SPsubstitution level was higher than 10 This was probablybecause of higher percentage of water absorption by SP Thedough could not hold the water under the double effects of
mechanical shear and heating The Mixolab mechanical armskidded in the process of mixing therefore the instrumentcould not detect the torque value From the existing data itwas observed that MPT significantly decreased with increas-ing level of SP possibly due to lower content of starch andhigher amount of water in the dough
32 Dough Stickiness Stickiness (DS) ofwhey and soy proteinenriched wheat flour dough was also shown in Table 1With increasing WP content the stickiness of the doughincreased from 2337 to 14271 g whereas the stickiness of thedough with addition of soy protein decreased from 2337 to1377 g Dough stickiness is caused by an interactive balancebetween adhesion and cohesion [21] Adhesion represents theinteraction between amaterial (dough) and a surface (probe)whereas cohesion describes the interactions inside the dough[22] In wheat flour gluten absorbed water to induce proteininteractions that play a critical role in dough stickiness [23]As the WP content increased the hydration of WP resultedin higher surface adhesion which played a leading role in theincrease of dough stickiness However in wheat-SP doughdilution of gluten and higher percentage of water led to asharp decrease of dough stickiness
33 Rheological Measurements The rheological properties ofWP and SP enriched wheat flour dough were studied usinga controlled-stress rheometer and the results were shown inFigure 1 The storage modulus (1198661015840) is a measure of the solidor elastic character of the dough and the loss modulus (11986610158401015840)is a measure of the liquid or viscous character tan 120575 (119866101584010158401198661015840)indicates the relative contributions of the viscous and elasticcharacteristics of the dough Figure 1 showed that that 1198661015840and 11986610158401015840 decreased and tan 120575 increased with increasing WPproportion in wheat doughs indicating a weakened glutennetwork However 1198661015840 increased and 11986610158401015840 and tan 120575 decreasedwith increasing SP proportion in wheat doughs potentiallydue to soy protein aggregation within the medium It wasreported that SP can increase disulphide linkage providingelasticity for baked goods [9 18] The results were also con-sistent with the rheological measurements taken by MixolabThe addition of WP softened the dough system due to theinterference with the gluten network [6] while soy proteinenhanced stability and elasticity of the dough
All protein enriched wheat doughs demonstrated anincrease in storage and loss modulus with increase in fre-quency (Figure 1) However the addition of WP increasedthe frequency dependence as indicated by the increase of thetan 120575 slope compared to that of wheat dough control (Fig-ure 1(b)) All dough samples showed a soft gel-like viscoelasticbehavior with 1198661015840 higher than 11986610158401015840 except the dough with 30WP substitution which showed a crossover at 158 rads Thiscrossover was associated with a change in the viscoelasticbehavior suggesting that the viscous component becamemore relevant than elastic one when frequency was higherthan 158 rads
Temperature sweep of doughs with different WP and SPsubstitution levels was shown in Figure 2 During the teststhree distinct stages of dynamic rheological changes were
Journal of Food Quality 5
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
103
104
G㰀㰀
(Pa)
103
104
G㰀
(Pa)
(a)
0102030
tan 훿
1 10 100
Angular frequency (rads)
04
08
12
tan훿
(b)
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀
(Pa)
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀㰀
(Pa)
(c)
0102030
tan 훿
1 10 100
Angular frequency (rads)
021
024
027
030
033
tan훿
(d)
Figure 1 The effect of whey and soy protein addition on 1198661015840 11986610158401015840 and tan 120575 of wheat dough with frequency sweep WP ((a) (b)) SP ((c) (d))
observed For wheat dough the first stage was observed from30∘C to 54∘C As the temperature increased the values of1198661015840 and 11986610158401015840 decreased slightly possibly due to hydrolysis ofdamaged starch by amylaseThe second stage was observed attemperatures above 54∘C At this stage 1198661015840 increased rapidlyand reached a maximum value at 72∘C indicating the gela-tinization of starch During gelatinization amylose chainsleached out into the aqueous intergranular phase increasingdough viscosity and elasticity [24] At the third stage starchgelatinization was complete and1198661015840 and11986610158401015840 began to decreasebecause of starch degradation Upon the addition of WPthe transition temperature and the temperature at which themaximum value of 1198661015840 and 11986610158401015840 was observed were clearlydelayed and dependent on the amount of WP added Theincrease in transition temperature was consistent with the
results obtained using Mixolab which indicated that WPwould compete forwaterwith the starch and glutenmoleculesin the dough system The peak value of 1198661015840 and 11986610158401015840 of thedough significantly increased with the increasing level ofWPfrom 0 to 20 and slightly decreased with further increaseof WP level to 30 The heat-induced gelation of WP wasmainly responsible for the increase of1198661015840 and11986610158401015840 In additionheat treatment of WP changes its structure from the nativecompact folded to a denatured unfolded structure [6]There-fore the sites for cross-linking among proteins and starchesincrease with an increase in protein concentration whichwill subsequently affect the properties of the dough It wasreported that WPcassava starch composite gels containingup to 20 cassava starch in the system showed enhancedviscoelastic properties as compared to gels made from either
6 Journal of Food Quality
8460 724836
Temperature (∘C)
010
2030
103
104
105
G㰀
(Pa)
(a)
103
104
105
G㰀㰀
(Pa)
8460 724836
Temperature (∘C)
010
2030
(b)
8460 724836
Temperature (∘C)
104
105
G㰀
(Pa)
010
2030
(c)
8460 724836
Temperature (∘C)
104
105
G㰀㰀
(Pa)
010
2030
(d)
Figure 2 The effect of whey and soy protein addition on 1198661015840 and 11986610158401015840 of wheat dough with temperature sweep WP ((a) (b)) SP ((c) (d))
component alone meaning synergistic interactions betweenWP and starch [25] Compared to WP wheat-SP doughfollowed quite similar tendencies of 1198661015840 and 11986610158401015840 as wheatdough control The transition temperature was at 54∘C andthe temperature for the maximum value of 1198661015840 and 11986610158401015840 wasat 72∘C However 1198661015840 and 11986610158401015840 decreased with the increasingconcentration of SP because of decreased starch content ofthe dough and higher water absorption and weaker gellingeffect of SP
34 Scanning Electron Microscopy The microstructure ofwheat flour dough as influenced by the substitution of 10and 30 of WP and SP is presented in Figure 3 Micrographof wheat dough is shown in Figure 3(a) The figure presentedthat the dough had a relatively smooth surface and starchgranules were embedded in the gluten matrix To compare
the effects ofWP and SP enrichment it was clearly seen fromFigures 3(b) and 3(c) that starch granules were still partlyembedded in the protein matrix due to the surface adhesioninduced by WP However hollows or ditches were observedon the dough surface indicating that the continuity of thegluten matrix had been disrupted by WP With the additionof 10 SP (Figure 3(d)) it could be seen that starch granuleswere separated from the protein matrix meaning disruptionin the well-defined protein-starch complex of wheat flourdough However the protein matrix composed of glutenand SP seemed more compact beyond fragmented areasprobably due to previously mentioned aggregation of SP andits higher water binding capacity With the addition of 30SP (Figure 3(e)) the aggregation of SP induced formation ofsoy protein network which provided a protective effect onstarch-protein complex thus leading to higher stability andelasticity of the dough
Journal of Food Quality 7
N D107 times500 200 um
(a)N times500 200 umD9
(b)
N times500 200 umD104
(c)N times500 200 umD91
(d)
N times500 200 umD98
(e)
Figure 3 Scanning electron micrographs of dough with different percentage substitution of WP and SP (a) Control (b) Control + 10WP(c) Control + 30WP (d) Control + 10 SP (e) Control + 30 SP
35 Cookie Quality Characteristics Table 2 showed the effectof substitution of wheat flour with WP and SP on the qualityparameters of cookies Usually higher spread ratio is con-sidered as one of the desirable quality attributes [26] Fromthe results the spread ratio of cookies continually decreasedfrom639 to 400with the increase ofWP content Differentlythe incorporation of SP decreased the cookie spread ratiofrom 639 to 566 and then increased to 686 The resultsabove based on SP enrichment were not in agreement withprevious studies [27ndash29] who reported a decrease in spreadratio of cookies with increase in proteins and concluded thatthe incorporation of foreign proteins interfered with gluten
development and therefore had negative effects on bakingproducts especially when amount of foreign proteins washigher than 5However things were different when amountof SP was higher than gluten content The aggregation ofSP induced formation of soy protein network which helpedincrease the elasticity and extensibility of the wheat doughthus leading to increased spread ratio The soy proteinnetworkmight also confer a protective effect on partial glutenstructure for obtaining an improvement in the quality ofbakery products The results were consistent with Mixolabmeasurements which showed that both MMT and MST firstdecreased and then increasedwith the further increasing level
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Journal of Food Quality 3
Table 1 Effect of whey and soy protein addition on thermomechanical properties and stickiness of wheat dougha
MWA()
MDT(min)
MST(min)
MMT(Nm)
PW(Nm)
PT(∘C)
MPT(Nm)
MBD(Nm)
MSB(Nm)
DS(g)
Control 538 112 plusmn007ab
762 plusmn028c 050 plusmn 0e 063 plusmn001e
5560 plusmn026a
221 plusmn003c
042 plusmn002a
167 plusmn001c
2337 plusmn964a
Whey protein
5 498 266 plusmn039c
463 plusmn008ab 030 plusmn 0c 080 plusmn 0g 5825 plusmn035bc
228 plusmn001c
059 plusmn003ab 09 plusmn 003
a 4476 plusmn1231b
10 471 335 plusmn004c
376 plusmn095a
024 plusmn001b
082 plusmn001gh
5830 plusmn099bc 23 plusmn 001
c 063 plusmn 0bc 089 plusmn003a6531 plusmn2349c
15 442 413 plusmn008d
375 plusmn004a 023 plusmn 0b 085 plusmn 0h 6020 plusmn071cd 249 plusmn 0d 084 plusmn001c 08 plusmn 005
a 11231 plusmn354d
20 432 442 plusmn002d
366 plusmn008a
020 plusmn001b 089 plusmn 0i 6060 plusmn028cd
275 plusmn001e
126 plusmn014d 08 plusmn 015a 13698 plusmn1166e
25 430 428 plusmn022d
423 plusmn018a 011 plusmn 0a 097 plusmn002j
6220 plusmn041d
284 plusmn006e
193 plusmn001e
093 plusmn002a
13157 plusmn1793e
30 427 422 plusmn035d
526 plusmn023ab
012 plusmn001a
097 plusmn002j
6180 plusmn071d
305 plusmn004f
231 plusmn006f
099 plusmn006a
14271 plusmn996e
Soy protein
5 588 081 plusmn011a
590 plusmn029b
043 plusmn001d
067 plusmn001f
5673 plusmn057ab
200 plusmn001b
055 plusmn001ab
140 plusmn002b
1917 plusmn593a
10 651 153 plusmn010b
840 plusmn091cd 050 plusmn 0e 061 plusmn002de
5723 plusmn075ab
177 plusmn001a
070 plusmn004bc
144 plusmn004b
1599 plusmn314a
15 720 161 plusmn003b
899 plusmn015cde
055 plusmn001f
058 plusmn002d mdash mdash mdash mdash 1535 plusmn
359a
20 793 167 plusmn018b
983 plusmn034de
058 plusmn001f
053 plusmn001c mdash mdash mdash mdash 1698 plusmn
293a
25 870 163 plusmn006b
1001 plusmn013e
062 plusmn003g
048 plusmn002b mdash mdash mdash mdash 1480 plusmn
168a
30 944 163 plusmn022b
1047 plusmn054e
066 plusmn001h
044 plusmn001a mdash mdash mdash mdash 1377 plusmn
266aaData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different119901 le 005
standardwhite porcelain on color whichwas calculated usingthe following equation
Δ119864 = radic(119871lowast minus 119871 119904)2 + (119886lowast minus 119886119904)2 + (119887lowast minus 119887119904)2 (1)
where 119871 119904 119886119904 and 119887119904 are values of standard white porcelain9713 021 and 187 respectively and 119871lowast 119886lowast and 119887lowast are thedetermined values of cookies
27 Consumer Acceptability Test The consumer acceptabilitystudy was carried out in the Sensory Evaluation AnalysisLaboratory of College of Food Science and Engineeringat Nanjing University of Finance and Economics NanjingChina A consumer panel consisting of 50 subjects wasrecruited to rate cookies on their overall acceptability andother attributes All panelists were cookie consumers A 9-point hedonic scale (1 = ldquodislike extremelyrdquo 5 = ldquoneither likenor dislikerdquo and 9= ldquolike extremelyrdquo)was used to evaluate theproducts Cookies were rated for overall acceptability accept-ability of hardness texturemouth feel colorappearance andflavor Cookies with an overall acceptability score above 5were considered as acceptable The cookies were prepared 1day prior to testing and stored at room temperature in sealedplastic bags All the samples were randomized using 3-digit
codes The order of the treatments served to the consumerswas also random Drinking water was used to cleanse mouthbetween the samples
28 Statistical Analysis Statistical analysis of the data wasperformed usingOrigin 90 (OriginLabCorp NorthamptonMA) Statistical significance of differences in means was cal-culated using ANOVA and Bonferronirsquos multiple comparisontests at 119901 lt 005
3 Results and Discussion
31 MixolabMeasurements Mixolab allows the characteriza-tion of the physicochemical behavior of protein and starch indough when subjected to dual mechanical shear and temper-ature constraints (Table 1)Whey protein (WP) incorporation(0sim30) decreased MWA of wheat dough from 538 to427 Indrani et al [5] also reported that the substitutionof wheat flour with WP decreased water absorption As thesubstitution level of WP increased from 0 to 20 MDTincreased and MST decreased However as the WP level wasfurther increased to 30 no significant changes forMDT butMST increased from 366 to 526min Dough development
4 Journal of Food Quality
time (MDT) and stability time (MST) are indicators of flourstrength with higher values suggesting stronger dough inwhich wheat gluten plays a critical role in the formation ofa three-dimensional viscoelastic structure [15] The additionof WP led to a complex system and delayed the hydrationand stretching and alignment of the wheat gluten leading tothe increase of MDT MST decreased due to the dilution ofwheat gluten and WP interference with the gluten networkZadow [16] reported that wheat flour dough weakening byWP is due to interference by WP sulfhydryl groups of thenormal sulfhydryldisulfide interchange reaction that occursduring wheat flour dough development At concentrationgreater than 20 the addition of WP significantly increaseddough stickiness (DS Table 1) and subsequently increasedMST Dough MMT reflects a weakening of wheat proteinThe addition of WP diluted the concentration of gluten anddestroyed the continuous state of the wheat flour doughrendering it difficult to form a stable gluten network structureunder the double effects ofmechanical force and heating thusMMT continued to decrease and PW continued to increase
During the heating stage starch granules absorb wateravailable in the medium and swell Amylose chains leachout into the aqueous intergranular phase promoting anincrease in viscosity and leading to peak in torque Withincreasing WP PT also significantly increased WP additiondecreased dough water absorption At the same time WP isexpected to compete for water with the primary starch chainsduring heating and this might cause the observed pastingtemperature to increase [17] MPT significantly increasedpossibly due to WP gelation Marco and Rosell [18] reportedthat the thermally induced gelation of the proteins developedduring the heat treatment which greatlymodified rheologicalbehaviors of the dough WP forms viscoelastic gels uponheating above its denaturation temperature [19]
In response to the addition of WP MBD increasedindicating that the addition of WP reduced the thermalstability of the starch in doughThe addition ofWP destroyedthe continuous gluten network structure and subsequentlyweakening its protective effect on starch subjected to amylaseAs the substitution level of WP increased MSB of thedough first decreased and then increased MSB might havedecreased because the proportion of starch decreased Athigher WP concentrations the strengthening of the WP gelduring the cooling stage might have caused the rise again inMSB
Compared to WP wheat flour-soy protein (SP) doughexhibited different behaviors in Mixolab measurements Theincorporation of SP (0sim30) increased MWA from 538to 944 in wheat flour dough MDT MST and MMTfirst decreased at 5 substitution level and then continuallyincreased with the further increase of SP level from 5 to30 The increase of above parameters in the presence ofSP was attributed to the aggregation of SP and its higherwater binding capacity in the dough system which increasedthe mechanical tolerance of the dough [9 20] However inthe heating stage no Mixolab data were obtained when SPsubstitution level was higher than 10 This was probablybecause of higher percentage of water absorption by SP Thedough could not hold the water under the double effects of
mechanical shear and heating The Mixolab mechanical armskidded in the process of mixing therefore the instrumentcould not detect the torque value From the existing data itwas observed that MPT significantly decreased with increas-ing level of SP possibly due to lower content of starch andhigher amount of water in the dough
32 Dough Stickiness Stickiness (DS) ofwhey and soy proteinenriched wheat flour dough was also shown in Table 1With increasing WP content the stickiness of the doughincreased from 2337 to 14271 g whereas the stickiness of thedough with addition of soy protein decreased from 2337 to1377 g Dough stickiness is caused by an interactive balancebetween adhesion and cohesion [21] Adhesion represents theinteraction between amaterial (dough) and a surface (probe)whereas cohesion describes the interactions inside the dough[22] In wheat flour gluten absorbed water to induce proteininteractions that play a critical role in dough stickiness [23]As the WP content increased the hydration of WP resultedin higher surface adhesion which played a leading role in theincrease of dough stickiness However in wheat-SP doughdilution of gluten and higher percentage of water led to asharp decrease of dough stickiness
33 Rheological Measurements The rheological properties ofWP and SP enriched wheat flour dough were studied usinga controlled-stress rheometer and the results were shown inFigure 1 The storage modulus (1198661015840) is a measure of the solidor elastic character of the dough and the loss modulus (11986610158401015840)is a measure of the liquid or viscous character tan 120575 (119866101584010158401198661015840)indicates the relative contributions of the viscous and elasticcharacteristics of the dough Figure 1 showed that that 1198661015840and 11986610158401015840 decreased and tan 120575 increased with increasing WPproportion in wheat doughs indicating a weakened glutennetwork However 1198661015840 increased and 11986610158401015840 and tan 120575 decreasedwith increasing SP proportion in wheat doughs potentiallydue to soy protein aggregation within the medium It wasreported that SP can increase disulphide linkage providingelasticity for baked goods [9 18] The results were also con-sistent with the rheological measurements taken by MixolabThe addition of WP softened the dough system due to theinterference with the gluten network [6] while soy proteinenhanced stability and elasticity of the dough
All protein enriched wheat doughs demonstrated anincrease in storage and loss modulus with increase in fre-quency (Figure 1) However the addition of WP increasedthe frequency dependence as indicated by the increase of thetan 120575 slope compared to that of wheat dough control (Fig-ure 1(b)) All dough samples showed a soft gel-like viscoelasticbehavior with 1198661015840 higher than 11986610158401015840 except the dough with 30WP substitution which showed a crossover at 158 rads Thiscrossover was associated with a change in the viscoelasticbehavior suggesting that the viscous component becamemore relevant than elastic one when frequency was higherthan 158 rads
Temperature sweep of doughs with different WP and SPsubstitution levels was shown in Figure 2 During the teststhree distinct stages of dynamic rheological changes were
Journal of Food Quality 5
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
103
104
G㰀㰀
(Pa)
103
104
G㰀
(Pa)
(a)
0102030
tan 훿
1 10 100
Angular frequency (rads)
04
08
12
tan훿
(b)
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀
(Pa)
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀㰀
(Pa)
(c)
0102030
tan 훿
1 10 100
Angular frequency (rads)
021
024
027
030
033
tan훿
(d)
Figure 1 The effect of whey and soy protein addition on 1198661015840 11986610158401015840 and tan 120575 of wheat dough with frequency sweep WP ((a) (b)) SP ((c) (d))
observed For wheat dough the first stage was observed from30∘C to 54∘C As the temperature increased the values of1198661015840 and 11986610158401015840 decreased slightly possibly due to hydrolysis ofdamaged starch by amylaseThe second stage was observed attemperatures above 54∘C At this stage 1198661015840 increased rapidlyand reached a maximum value at 72∘C indicating the gela-tinization of starch During gelatinization amylose chainsleached out into the aqueous intergranular phase increasingdough viscosity and elasticity [24] At the third stage starchgelatinization was complete and1198661015840 and11986610158401015840 began to decreasebecause of starch degradation Upon the addition of WPthe transition temperature and the temperature at which themaximum value of 1198661015840 and 11986610158401015840 was observed were clearlydelayed and dependent on the amount of WP added Theincrease in transition temperature was consistent with the
results obtained using Mixolab which indicated that WPwould compete forwaterwith the starch and glutenmoleculesin the dough system The peak value of 1198661015840 and 11986610158401015840 of thedough significantly increased with the increasing level ofWPfrom 0 to 20 and slightly decreased with further increaseof WP level to 30 The heat-induced gelation of WP wasmainly responsible for the increase of1198661015840 and11986610158401015840 In additionheat treatment of WP changes its structure from the nativecompact folded to a denatured unfolded structure [6]There-fore the sites for cross-linking among proteins and starchesincrease with an increase in protein concentration whichwill subsequently affect the properties of the dough It wasreported that WPcassava starch composite gels containingup to 20 cassava starch in the system showed enhancedviscoelastic properties as compared to gels made from either
6 Journal of Food Quality
8460 724836
Temperature (∘C)
010
2030
103
104
105
G㰀
(Pa)
(a)
103
104
105
G㰀㰀
(Pa)
8460 724836
Temperature (∘C)
010
2030
(b)
8460 724836
Temperature (∘C)
104
105
G㰀
(Pa)
010
2030
(c)
8460 724836
Temperature (∘C)
104
105
G㰀㰀
(Pa)
010
2030
(d)
Figure 2 The effect of whey and soy protein addition on 1198661015840 and 11986610158401015840 of wheat dough with temperature sweep WP ((a) (b)) SP ((c) (d))
component alone meaning synergistic interactions betweenWP and starch [25] Compared to WP wheat-SP doughfollowed quite similar tendencies of 1198661015840 and 11986610158401015840 as wheatdough control The transition temperature was at 54∘C andthe temperature for the maximum value of 1198661015840 and 11986610158401015840 wasat 72∘C However 1198661015840 and 11986610158401015840 decreased with the increasingconcentration of SP because of decreased starch content ofthe dough and higher water absorption and weaker gellingeffect of SP
34 Scanning Electron Microscopy The microstructure ofwheat flour dough as influenced by the substitution of 10and 30 of WP and SP is presented in Figure 3 Micrographof wheat dough is shown in Figure 3(a) The figure presentedthat the dough had a relatively smooth surface and starchgranules were embedded in the gluten matrix To compare
the effects ofWP and SP enrichment it was clearly seen fromFigures 3(b) and 3(c) that starch granules were still partlyembedded in the protein matrix due to the surface adhesioninduced by WP However hollows or ditches were observedon the dough surface indicating that the continuity of thegluten matrix had been disrupted by WP With the additionof 10 SP (Figure 3(d)) it could be seen that starch granuleswere separated from the protein matrix meaning disruptionin the well-defined protein-starch complex of wheat flourdough However the protein matrix composed of glutenand SP seemed more compact beyond fragmented areasprobably due to previously mentioned aggregation of SP andits higher water binding capacity With the addition of 30SP (Figure 3(e)) the aggregation of SP induced formation ofsoy protein network which provided a protective effect onstarch-protein complex thus leading to higher stability andelasticity of the dough
Journal of Food Quality 7
N D107 times500 200 um
(a)N times500 200 umD9
(b)
N times500 200 umD104
(c)N times500 200 umD91
(d)
N times500 200 umD98
(e)
Figure 3 Scanning electron micrographs of dough with different percentage substitution of WP and SP (a) Control (b) Control + 10WP(c) Control + 30WP (d) Control + 10 SP (e) Control + 30 SP
35 Cookie Quality Characteristics Table 2 showed the effectof substitution of wheat flour with WP and SP on the qualityparameters of cookies Usually higher spread ratio is con-sidered as one of the desirable quality attributes [26] Fromthe results the spread ratio of cookies continually decreasedfrom639 to 400with the increase ofWP content Differentlythe incorporation of SP decreased the cookie spread ratiofrom 639 to 566 and then increased to 686 The resultsabove based on SP enrichment were not in agreement withprevious studies [27ndash29] who reported a decrease in spreadratio of cookies with increase in proteins and concluded thatthe incorporation of foreign proteins interfered with gluten
development and therefore had negative effects on bakingproducts especially when amount of foreign proteins washigher than 5However things were different when amountof SP was higher than gluten content The aggregation ofSP induced formation of soy protein network which helpedincrease the elasticity and extensibility of the wheat doughthus leading to increased spread ratio The soy proteinnetworkmight also confer a protective effect on partial glutenstructure for obtaining an improvement in the quality ofbakery products The results were consistent with Mixolabmeasurements which showed that both MMT and MST firstdecreased and then increasedwith the further increasing level
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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PeptidesInternational Journal of
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International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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GenomicsInternational Journal of
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BioinformaticsAdvances in
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Signal TransductionJournal of
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Evolutionary BiologyInternational Journal of
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Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Genetics Research International
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International Journal of
Microbiology
4 Journal of Food Quality
time (MDT) and stability time (MST) are indicators of flourstrength with higher values suggesting stronger dough inwhich wheat gluten plays a critical role in the formation ofa three-dimensional viscoelastic structure [15] The additionof WP led to a complex system and delayed the hydrationand stretching and alignment of the wheat gluten leading tothe increase of MDT MST decreased due to the dilution ofwheat gluten and WP interference with the gluten networkZadow [16] reported that wheat flour dough weakening byWP is due to interference by WP sulfhydryl groups of thenormal sulfhydryldisulfide interchange reaction that occursduring wheat flour dough development At concentrationgreater than 20 the addition of WP significantly increaseddough stickiness (DS Table 1) and subsequently increasedMST Dough MMT reflects a weakening of wheat proteinThe addition of WP diluted the concentration of gluten anddestroyed the continuous state of the wheat flour doughrendering it difficult to form a stable gluten network structureunder the double effects ofmechanical force and heating thusMMT continued to decrease and PW continued to increase
During the heating stage starch granules absorb wateravailable in the medium and swell Amylose chains leachout into the aqueous intergranular phase promoting anincrease in viscosity and leading to peak in torque Withincreasing WP PT also significantly increased WP additiondecreased dough water absorption At the same time WP isexpected to compete for water with the primary starch chainsduring heating and this might cause the observed pastingtemperature to increase [17] MPT significantly increasedpossibly due to WP gelation Marco and Rosell [18] reportedthat the thermally induced gelation of the proteins developedduring the heat treatment which greatlymodified rheologicalbehaviors of the dough WP forms viscoelastic gels uponheating above its denaturation temperature [19]
In response to the addition of WP MBD increasedindicating that the addition of WP reduced the thermalstability of the starch in doughThe addition ofWP destroyedthe continuous gluten network structure and subsequentlyweakening its protective effect on starch subjected to amylaseAs the substitution level of WP increased MSB of thedough first decreased and then increased MSB might havedecreased because the proportion of starch decreased Athigher WP concentrations the strengthening of the WP gelduring the cooling stage might have caused the rise again inMSB
Compared to WP wheat flour-soy protein (SP) doughexhibited different behaviors in Mixolab measurements Theincorporation of SP (0sim30) increased MWA from 538to 944 in wheat flour dough MDT MST and MMTfirst decreased at 5 substitution level and then continuallyincreased with the further increase of SP level from 5 to30 The increase of above parameters in the presence ofSP was attributed to the aggregation of SP and its higherwater binding capacity in the dough system which increasedthe mechanical tolerance of the dough [9 20] However inthe heating stage no Mixolab data were obtained when SPsubstitution level was higher than 10 This was probablybecause of higher percentage of water absorption by SP Thedough could not hold the water under the double effects of
mechanical shear and heating The Mixolab mechanical armskidded in the process of mixing therefore the instrumentcould not detect the torque value From the existing data itwas observed that MPT significantly decreased with increas-ing level of SP possibly due to lower content of starch andhigher amount of water in the dough
32 Dough Stickiness Stickiness (DS) ofwhey and soy proteinenriched wheat flour dough was also shown in Table 1With increasing WP content the stickiness of the doughincreased from 2337 to 14271 g whereas the stickiness of thedough with addition of soy protein decreased from 2337 to1377 g Dough stickiness is caused by an interactive balancebetween adhesion and cohesion [21] Adhesion represents theinteraction between amaterial (dough) and a surface (probe)whereas cohesion describes the interactions inside the dough[22] In wheat flour gluten absorbed water to induce proteininteractions that play a critical role in dough stickiness [23]As the WP content increased the hydration of WP resultedin higher surface adhesion which played a leading role in theincrease of dough stickiness However in wheat-SP doughdilution of gluten and higher percentage of water led to asharp decrease of dough stickiness
33 Rheological Measurements The rheological properties ofWP and SP enriched wheat flour dough were studied usinga controlled-stress rheometer and the results were shown inFigure 1 The storage modulus (1198661015840) is a measure of the solidor elastic character of the dough and the loss modulus (11986610158401015840)is a measure of the liquid or viscous character tan 120575 (119866101584010158401198661015840)indicates the relative contributions of the viscous and elasticcharacteristics of the dough Figure 1 showed that that 1198661015840and 11986610158401015840 decreased and tan 120575 increased with increasing WPproportion in wheat doughs indicating a weakened glutennetwork However 1198661015840 increased and 11986610158401015840 and tan 120575 decreasedwith increasing SP proportion in wheat doughs potentiallydue to soy protein aggregation within the medium It wasreported that SP can increase disulphide linkage providingelasticity for baked goods [9 18] The results were also con-sistent with the rheological measurements taken by MixolabThe addition of WP softened the dough system due to theinterference with the gluten network [6] while soy proteinenhanced stability and elasticity of the dough
All protein enriched wheat doughs demonstrated anincrease in storage and loss modulus with increase in fre-quency (Figure 1) However the addition of WP increasedthe frequency dependence as indicated by the increase of thetan 120575 slope compared to that of wheat dough control (Fig-ure 1(b)) All dough samples showed a soft gel-like viscoelasticbehavior with 1198661015840 higher than 11986610158401015840 except the dough with 30WP substitution which showed a crossover at 158 rads Thiscrossover was associated with a change in the viscoelasticbehavior suggesting that the viscous component becamemore relevant than elastic one when frequency was higherthan 158 rads
Temperature sweep of doughs with different WP and SPsubstitution levels was shown in Figure 2 During the teststhree distinct stages of dynamic rheological changes were
Journal of Food Quality 5
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
103
104
G㰀㰀
(Pa)
103
104
G㰀
(Pa)
(a)
0102030
tan 훿
1 10 100
Angular frequency (rads)
04
08
12
tan훿
(b)
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀
(Pa)
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀㰀
(Pa)
(c)
0102030
tan 훿
1 10 100
Angular frequency (rads)
021
024
027
030
033
tan훿
(d)
Figure 1 The effect of whey and soy protein addition on 1198661015840 11986610158401015840 and tan 120575 of wheat dough with frequency sweep WP ((a) (b)) SP ((c) (d))
observed For wheat dough the first stage was observed from30∘C to 54∘C As the temperature increased the values of1198661015840 and 11986610158401015840 decreased slightly possibly due to hydrolysis ofdamaged starch by amylaseThe second stage was observed attemperatures above 54∘C At this stage 1198661015840 increased rapidlyand reached a maximum value at 72∘C indicating the gela-tinization of starch During gelatinization amylose chainsleached out into the aqueous intergranular phase increasingdough viscosity and elasticity [24] At the third stage starchgelatinization was complete and1198661015840 and11986610158401015840 began to decreasebecause of starch degradation Upon the addition of WPthe transition temperature and the temperature at which themaximum value of 1198661015840 and 11986610158401015840 was observed were clearlydelayed and dependent on the amount of WP added Theincrease in transition temperature was consistent with the
results obtained using Mixolab which indicated that WPwould compete forwaterwith the starch and glutenmoleculesin the dough system The peak value of 1198661015840 and 11986610158401015840 of thedough significantly increased with the increasing level ofWPfrom 0 to 20 and slightly decreased with further increaseof WP level to 30 The heat-induced gelation of WP wasmainly responsible for the increase of1198661015840 and11986610158401015840 In additionheat treatment of WP changes its structure from the nativecompact folded to a denatured unfolded structure [6]There-fore the sites for cross-linking among proteins and starchesincrease with an increase in protein concentration whichwill subsequently affect the properties of the dough It wasreported that WPcassava starch composite gels containingup to 20 cassava starch in the system showed enhancedviscoelastic properties as compared to gels made from either
6 Journal of Food Quality
8460 724836
Temperature (∘C)
010
2030
103
104
105
G㰀
(Pa)
(a)
103
104
105
G㰀㰀
(Pa)
8460 724836
Temperature (∘C)
010
2030
(b)
8460 724836
Temperature (∘C)
104
105
G㰀
(Pa)
010
2030
(c)
8460 724836
Temperature (∘C)
104
105
G㰀㰀
(Pa)
010
2030
(d)
Figure 2 The effect of whey and soy protein addition on 1198661015840 and 11986610158401015840 of wheat dough with temperature sweep WP ((a) (b)) SP ((c) (d))
component alone meaning synergistic interactions betweenWP and starch [25] Compared to WP wheat-SP doughfollowed quite similar tendencies of 1198661015840 and 11986610158401015840 as wheatdough control The transition temperature was at 54∘C andthe temperature for the maximum value of 1198661015840 and 11986610158401015840 wasat 72∘C However 1198661015840 and 11986610158401015840 decreased with the increasingconcentration of SP because of decreased starch content ofthe dough and higher water absorption and weaker gellingeffect of SP
34 Scanning Electron Microscopy The microstructure ofwheat flour dough as influenced by the substitution of 10and 30 of WP and SP is presented in Figure 3 Micrographof wheat dough is shown in Figure 3(a) The figure presentedthat the dough had a relatively smooth surface and starchgranules were embedded in the gluten matrix To compare
the effects ofWP and SP enrichment it was clearly seen fromFigures 3(b) and 3(c) that starch granules were still partlyembedded in the protein matrix due to the surface adhesioninduced by WP However hollows or ditches were observedon the dough surface indicating that the continuity of thegluten matrix had been disrupted by WP With the additionof 10 SP (Figure 3(d)) it could be seen that starch granuleswere separated from the protein matrix meaning disruptionin the well-defined protein-starch complex of wheat flourdough However the protein matrix composed of glutenand SP seemed more compact beyond fragmented areasprobably due to previously mentioned aggregation of SP andits higher water binding capacity With the addition of 30SP (Figure 3(e)) the aggregation of SP induced formation ofsoy protein network which provided a protective effect onstarch-protein complex thus leading to higher stability andelasticity of the dough
Journal of Food Quality 7
N D107 times500 200 um
(a)N times500 200 umD9
(b)
N times500 200 umD104
(c)N times500 200 umD91
(d)
N times500 200 umD98
(e)
Figure 3 Scanning electron micrographs of dough with different percentage substitution of WP and SP (a) Control (b) Control + 10WP(c) Control + 30WP (d) Control + 10 SP (e) Control + 30 SP
35 Cookie Quality Characteristics Table 2 showed the effectof substitution of wheat flour with WP and SP on the qualityparameters of cookies Usually higher spread ratio is con-sidered as one of the desirable quality attributes [26] Fromthe results the spread ratio of cookies continually decreasedfrom639 to 400with the increase ofWP content Differentlythe incorporation of SP decreased the cookie spread ratiofrom 639 to 566 and then increased to 686 The resultsabove based on SP enrichment were not in agreement withprevious studies [27ndash29] who reported a decrease in spreadratio of cookies with increase in proteins and concluded thatthe incorporation of foreign proteins interfered with gluten
development and therefore had negative effects on bakingproducts especially when amount of foreign proteins washigher than 5However things were different when amountof SP was higher than gluten content The aggregation ofSP induced formation of soy protein network which helpedincrease the elasticity and extensibility of the wheat doughthus leading to increased spread ratio The soy proteinnetworkmight also confer a protective effect on partial glutenstructure for obtaining an improvement in the quality ofbakery products The results were consistent with Mixolabmeasurements which showed that both MMT and MST firstdecreased and then increasedwith the further increasing level
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Journal of Food Quality 5
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
103
104
G㰀㰀
(Pa)
103
104
G㰀
(Pa)
(a)
0102030
tan 훿
1 10 100
Angular frequency (rads)
04
08
12
tan훿
(b)
G㰀
G㰀㰀
1 10 100
Angular frequency (rads)
0102030
0102030
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀
(Pa)
104
2 times 104
3 times 104
4 times 104
5 times 104
6 times 104
G㰀㰀
(Pa)
(c)
0102030
tan 훿
1 10 100
Angular frequency (rads)
021
024
027
030
033
tan훿
(d)
Figure 1 The effect of whey and soy protein addition on 1198661015840 11986610158401015840 and tan 120575 of wheat dough with frequency sweep WP ((a) (b)) SP ((c) (d))
observed For wheat dough the first stage was observed from30∘C to 54∘C As the temperature increased the values of1198661015840 and 11986610158401015840 decreased slightly possibly due to hydrolysis ofdamaged starch by amylaseThe second stage was observed attemperatures above 54∘C At this stage 1198661015840 increased rapidlyand reached a maximum value at 72∘C indicating the gela-tinization of starch During gelatinization amylose chainsleached out into the aqueous intergranular phase increasingdough viscosity and elasticity [24] At the third stage starchgelatinization was complete and1198661015840 and11986610158401015840 began to decreasebecause of starch degradation Upon the addition of WPthe transition temperature and the temperature at which themaximum value of 1198661015840 and 11986610158401015840 was observed were clearlydelayed and dependent on the amount of WP added Theincrease in transition temperature was consistent with the
results obtained using Mixolab which indicated that WPwould compete forwaterwith the starch and glutenmoleculesin the dough system The peak value of 1198661015840 and 11986610158401015840 of thedough significantly increased with the increasing level ofWPfrom 0 to 20 and slightly decreased with further increaseof WP level to 30 The heat-induced gelation of WP wasmainly responsible for the increase of1198661015840 and11986610158401015840 In additionheat treatment of WP changes its structure from the nativecompact folded to a denatured unfolded structure [6]There-fore the sites for cross-linking among proteins and starchesincrease with an increase in protein concentration whichwill subsequently affect the properties of the dough It wasreported that WPcassava starch composite gels containingup to 20 cassava starch in the system showed enhancedviscoelastic properties as compared to gels made from either
6 Journal of Food Quality
8460 724836
Temperature (∘C)
010
2030
103
104
105
G㰀
(Pa)
(a)
103
104
105
G㰀㰀
(Pa)
8460 724836
Temperature (∘C)
010
2030
(b)
8460 724836
Temperature (∘C)
104
105
G㰀
(Pa)
010
2030
(c)
8460 724836
Temperature (∘C)
104
105
G㰀㰀
(Pa)
010
2030
(d)
Figure 2 The effect of whey and soy protein addition on 1198661015840 and 11986610158401015840 of wheat dough with temperature sweep WP ((a) (b)) SP ((c) (d))
component alone meaning synergistic interactions betweenWP and starch [25] Compared to WP wheat-SP doughfollowed quite similar tendencies of 1198661015840 and 11986610158401015840 as wheatdough control The transition temperature was at 54∘C andthe temperature for the maximum value of 1198661015840 and 11986610158401015840 wasat 72∘C However 1198661015840 and 11986610158401015840 decreased with the increasingconcentration of SP because of decreased starch content ofthe dough and higher water absorption and weaker gellingeffect of SP
34 Scanning Electron Microscopy The microstructure ofwheat flour dough as influenced by the substitution of 10and 30 of WP and SP is presented in Figure 3 Micrographof wheat dough is shown in Figure 3(a) The figure presentedthat the dough had a relatively smooth surface and starchgranules were embedded in the gluten matrix To compare
the effects ofWP and SP enrichment it was clearly seen fromFigures 3(b) and 3(c) that starch granules were still partlyembedded in the protein matrix due to the surface adhesioninduced by WP However hollows or ditches were observedon the dough surface indicating that the continuity of thegluten matrix had been disrupted by WP With the additionof 10 SP (Figure 3(d)) it could be seen that starch granuleswere separated from the protein matrix meaning disruptionin the well-defined protein-starch complex of wheat flourdough However the protein matrix composed of glutenand SP seemed more compact beyond fragmented areasprobably due to previously mentioned aggregation of SP andits higher water binding capacity With the addition of 30SP (Figure 3(e)) the aggregation of SP induced formation ofsoy protein network which provided a protective effect onstarch-protein complex thus leading to higher stability andelasticity of the dough
Journal of Food Quality 7
N D107 times500 200 um
(a)N times500 200 umD9
(b)
N times500 200 umD104
(c)N times500 200 umD91
(d)
N times500 200 umD98
(e)
Figure 3 Scanning electron micrographs of dough with different percentage substitution of WP and SP (a) Control (b) Control + 10WP(c) Control + 30WP (d) Control + 10 SP (e) Control + 30 SP
35 Cookie Quality Characteristics Table 2 showed the effectof substitution of wheat flour with WP and SP on the qualityparameters of cookies Usually higher spread ratio is con-sidered as one of the desirable quality attributes [26] Fromthe results the spread ratio of cookies continually decreasedfrom639 to 400with the increase ofWP content Differentlythe incorporation of SP decreased the cookie spread ratiofrom 639 to 566 and then increased to 686 The resultsabove based on SP enrichment were not in agreement withprevious studies [27ndash29] who reported a decrease in spreadratio of cookies with increase in proteins and concluded thatthe incorporation of foreign proteins interfered with gluten
development and therefore had negative effects on bakingproducts especially when amount of foreign proteins washigher than 5However things were different when amountof SP was higher than gluten content The aggregation ofSP induced formation of soy protein network which helpedincrease the elasticity and extensibility of the wheat doughthus leading to increased spread ratio The soy proteinnetworkmight also confer a protective effect on partial glutenstructure for obtaining an improvement in the quality ofbakery products The results were consistent with Mixolabmeasurements which showed that both MMT and MST firstdecreased and then increasedwith the further increasing level
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
6 Journal of Food Quality
8460 724836
Temperature (∘C)
010
2030
103
104
105
G㰀
(Pa)
(a)
103
104
105
G㰀㰀
(Pa)
8460 724836
Temperature (∘C)
010
2030
(b)
8460 724836
Temperature (∘C)
104
105
G㰀
(Pa)
010
2030
(c)
8460 724836
Temperature (∘C)
104
105
G㰀㰀
(Pa)
010
2030
(d)
Figure 2 The effect of whey and soy protein addition on 1198661015840 and 11986610158401015840 of wheat dough with temperature sweep WP ((a) (b)) SP ((c) (d))
component alone meaning synergistic interactions betweenWP and starch [25] Compared to WP wheat-SP doughfollowed quite similar tendencies of 1198661015840 and 11986610158401015840 as wheatdough control The transition temperature was at 54∘C andthe temperature for the maximum value of 1198661015840 and 11986610158401015840 wasat 72∘C However 1198661015840 and 11986610158401015840 decreased with the increasingconcentration of SP because of decreased starch content ofthe dough and higher water absorption and weaker gellingeffect of SP
34 Scanning Electron Microscopy The microstructure ofwheat flour dough as influenced by the substitution of 10and 30 of WP and SP is presented in Figure 3 Micrographof wheat dough is shown in Figure 3(a) The figure presentedthat the dough had a relatively smooth surface and starchgranules were embedded in the gluten matrix To compare
the effects ofWP and SP enrichment it was clearly seen fromFigures 3(b) and 3(c) that starch granules were still partlyembedded in the protein matrix due to the surface adhesioninduced by WP However hollows or ditches were observedon the dough surface indicating that the continuity of thegluten matrix had been disrupted by WP With the additionof 10 SP (Figure 3(d)) it could be seen that starch granuleswere separated from the protein matrix meaning disruptionin the well-defined protein-starch complex of wheat flourdough However the protein matrix composed of glutenand SP seemed more compact beyond fragmented areasprobably due to previously mentioned aggregation of SP andits higher water binding capacity With the addition of 30SP (Figure 3(e)) the aggregation of SP induced formation ofsoy protein network which provided a protective effect onstarch-protein complex thus leading to higher stability andelasticity of the dough
Journal of Food Quality 7
N D107 times500 200 um
(a)N times500 200 umD9
(b)
N times500 200 umD104
(c)N times500 200 umD91
(d)
N times500 200 umD98
(e)
Figure 3 Scanning electron micrographs of dough with different percentage substitution of WP and SP (a) Control (b) Control + 10WP(c) Control + 30WP (d) Control + 10 SP (e) Control + 30 SP
35 Cookie Quality Characteristics Table 2 showed the effectof substitution of wheat flour with WP and SP on the qualityparameters of cookies Usually higher spread ratio is con-sidered as one of the desirable quality attributes [26] Fromthe results the spread ratio of cookies continually decreasedfrom639 to 400with the increase ofWP content Differentlythe incorporation of SP decreased the cookie spread ratiofrom 639 to 566 and then increased to 686 The resultsabove based on SP enrichment were not in agreement withprevious studies [27ndash29] who reported a decrease in spreadratio of cookies with increase in proteins and concluded thatthe incorporation of foreign proteins interfered with gluten
development and therefore had negative effects on bakingproducts especially when amount of foreign proteins washigher than 5However things were different when amountof SP was higher than gluten content The aggregation ofSP induced formation of soy protein network which helpedincrease the elasticity and extensibility of the wheat doughthus leading to increased spread ratio The soy proteinnetworkmight also confer a protective effect on partial glutenstructure for obtaining an improvement in the quality ofbakery products The results were consistent with Mixolabmeasurements which showed that both MMT and MST firstdecreased and then increasedwith the further increasing level
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Journal of Food Quality 7
N D107 times500 200 um
(a)N times500 200 umD9
(b)
N times500 200 umD104
(c)N times500 200 umD91
(d)
N times500 200 umD98
(e)
Figure 3 Scanning electron micrographs of dough with different percentage substitution of WP and SP (a) Control (b) Control + 10WP(c) Control + 30WP (d) Control + 10 SP (e) Control + 30 SP
35 Cookie Quality Characteristics Table 2 showed the effectof substitution of wheat flour with WP and SP on the qualityparameters of cookies Usually higher spread ratio is con-sidered as one of the desirable quality attributes [26] Fromthe results the spread ratio of cookies continually decreasedfrom639 to 400with the increase ofWP content Differentlythe incorporation of SP decreased the cookie spread ratiofrom 639 to 566 and then increased to 686 The resultsabove based on SP enrichment were not in agreement withprevious studies [27ndash29] who reported a decrease in spreadratio of cookies with increase in proteins and concluded thatthe incorporation of foreign proteins interfered with gluten
development and therefore had negative effects on bakingproducts especially when amount of foreign proteins washigher than 5However things were different when amountof SP was higher than gluten content The aggregation ofSP induced formation of soy protein network which helpedincrease the elasticity and extensibility of the wheat doughthus leading to increased spread ratio The soy proteinnetworkmight also confer a protective effect on partial glutenstructure for obtaining an improvement in the quality ofbakery products The results were consistent with Mixolabmeasurements which showed that both MMT and MST firstdecreased and then increasedwith the further increasing level
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
8 Journal of Food Quality
Table 2 Effect of whey and soy protein addition on cookie quality parametersa
Spread ratio(119863119879)
Hardness(g)
Color values119871lowast 119886lowast 119887lowast Δ119864
Control 639 plusmn 012fg 48620 plusmn 3686b 6665 plusmn 035f 1021 plusmn 025a 3378 plusmn 069abc 4524Whey protein
5 627 plusmn 023efg 41102 plusmn 3603ab 6004 plusmn 069de 1530 plusmn 024e 3552 plusmn 020cd 523010 562 plusmn 038cd 49189 plusmn 1500b 5689 plusmn 013cd 1787 plusmn 011f 3627 plusmn 018d 558115 503 plusmn 011bc 58349 plusmn 4961c 5316 plusmn 120bc 1985 plusmn 013g 3583 plusmn 036d 589320 454 plusmn 009ab 71294 plusmn 3120d 5103 plusmn 138ab 2088 plusmn 013gh 3539 plusmn 064cd 606325 430 plusmn 025a 73014 plusmn 1180d 5019 plusmn 052ab 2146 plusmn 012h 3530 plusmn 068bcd 614230 400 plusmn 005a 75043 plusmn 1252d 4734 plusmn 089a 2168 plusmn 015h 3327 plusmn 022ab 6266
Soy protein5 592 plusmn 022def 44040 plusmn 2923ab 6613 plusmn 139f 1118 plusmn 010ab 3312 plusmn 078a 453610 566 plusmn 015de 44727 plusmn 2600ab 6498 plusmn 175f 1228 plusmn 137bc 3325 plusmn 086ab 465215 605 plusmn 008def 41800 plusmn 1764ab 6395 plusmn 059f 1349 plusmn 021cd 3371 plusmn 054abc 478620 626 plusmn 011efg 39008 plusmn 3630a 6295 plusmn 100ef 1394 plusmn 051de 3331 plusmn 130ab 484325 648 plusmn 031fg 36900 plusmn 2494a 6288 plusmn 269ef 1424 plusmn 073de 3463 plusmn 063abcd 494330 686 plusmn 008g 38726 plusmn 1030a 6473 plusmn 056f 1418 plusmn 037de 3425 plusmn 037abcd 4789
aData are presented as means plusmn standard deviation Data values with different letters in columns are significantly different 119901 le 005
Table 3 Consumer acceptability (9-point hedonic scale) analysis
Sensory attributes Overall acceptability Hardness Texturemouth feel Colorappearance FlavorControl 69 63 70 72 71Whey protein
10 62 60 57 55 7120 46 48 40 39 5430 37 42 32 27 43
Soy protein10 66 64 63 74 6920 68 69 66 69 6530 70 72 71 71 65
of SP The results indicated that the selection of the proteinsource and amount with appropriate functionalities seemedto play an important role in certain application
The texture was also markedly affected with increasinglevel of WP and SPThe hardness indicated by breaking forcein Table 2 increased with the increase in the level of WP butdecreasedwith the increase in the level of SP Compared to SPWP is a much better gelling protein [30] The heat-inducedgelation of WP led to higher stiffness of cookie dough Thecolors of cookies which was represented by 119871lowast 119886lowast 119887lowast andΔ119864 values were summarized in Table 2 119871lowast values representthe lightness of the cookies by level 0ndash100 Redness of cookiesis donated by 119886lowast values The 119887lowast values suggest the yellownessof cookies With increase in WP from 0 to 30 there weresignificant decrease in 119871lowast and increase in 119886lowast meaning lowerlightness and higher redness of cookiesThe rapid increase ofΔ119864with addition ofWP indicated the darker color of cookieswhich was mainly attributed to Maillard reactions betweensugar and free amino acids provided by WP Compared towheat flour control slight changes in color were observed forSP fortified cookies
36 ConsumerAcceptability Test Table 3 shows the consumeracceptability ratings for various sensory attributes of cookiesWith the addition of WP the scores of all sensory attributesand overall acceptability of the cookies decreased especiallyscores of color and texture The maximum amount of WPin the cookie that could be accepted by consumers was 10With the addition of SP the scores of hardness increased andthe scores of texture first decreased and then increased Theoverall acceptability also first decreased from 69 to 66 andthen increased to 70 which meant the cookies fortified withsoy proteins (0ndash30) are all acceptable and even preferredby consumers especially when higher amount of soy protein(like 30 replacement ratio) was applied
4 Conclusions
The effect of soy and whey proteins on the thermomechan-ical dynamic rheological and microstructural properties ofwheat dough and the cookie-making quality was comparedin this work The dilution of gluten by WP addition andthereby disruption of gluten structure led to lower quality
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Journal of Food Quality 9
of wheat dough and final cookie products Differently theaggregation of SP induced formation of soy protein networkwhich helped increase the elasticity and extensibility of thewheat dough and confer a protective effect on partial glutenstructure thus leading to increased spread ratio and overallacceptability of the cookies especially when higher amountof SP was incorporatedThe results indicated that selection ofthe protein source and amount with appropriate functionali-ties played an important role in certain applications of proteinfortified bakery products Further studies will be needed toexplore the changes of protein structure and network for SPfortified cookies
Conflicts of Interest
The authors declare that they have no conflicts of interest
Acknowledgments
The authors would like to acknowledge Key UniversityScience Research Project of Jiangsu Province for fundingthis project (Grant no 12KJA550002) The project was alsofunded by the Priority Academic Program Development ofJiangsu Higher Education Institutions (PAPDF) The authorsacknowledge the support from 2013 Jiangsu University Out-standing Science and Technology Innovation Team
References
[1] C R Storck E da Rosa Zavareze M A Gularte M C Elias CM Rosell and A R Guerra Dias ldquoProtein enrichment and itseffects on gluten-free bread characteristicsrdquo LWT - Food Scienceand Technology vol 53 no 1 pp 346ndash354 2013
[2] C Li H Enomoto S Ohki H Ohtomo and T Aoki ldquoImprove-ment of functional properties of whey protein isolate throughglycation and phosphorylation by dry heatingrdquo Journal of DairyScience vol 88 pp 4137ndash4145 2005
[3] A S Ammar S A Salem and F H Badr ldquoRheologicalproperties of wheat flour dough as affected by addition of wheyand soy proteinsrdquo Pakistan Journal of Nutrition vol 10 no 4pp 302ndash306 2011
[4] S Dhingra and S Jood ldquoOrganoleptic and nutritional evalu-ation of wheat breads supplemented with soybean and barleyflourrdquo Food Chemistry vol 77 no 4 pp 479ndash488 2002
[5] D Indrani P Prabhasankar J Rajiv and G V Rao ldquoInfluenceof whey protein concentrate on the rheological characteristicsof dough microstructure and quality of unleavened flat bread(parotta)rdquo Food Research International vol 40 no 10 pp 1254ndash1260 2007
[6] S Kenny K Wehrle M Auty and E K Arendt ldquoInfluence ofsodium caseinate and whey protein on baking properties andrheology of frozen doughrdquo Cereal Chemistry vol 78 no 4 pp458ndash463 2001
[7] P D Ribotta S A Arnulphi A E Leon and M C AnonldquoEffect of soybean addition on the rheological properties andbreadmaking quality of wheat flourrdquo Journal of the Science ofFood and Agriculture vol 85 pp 1889ndash1896 2005
[8] M Sudha G Rajeswari and G V Rao ldquoInfluence of defattedsoy flour and whey protein concentrate on dough rheological
characteristics and quality of instant vermicellirdquo Journal ofTexture Studies vol 42 pp 72ndash80 2011
[9] R Crockett P Ie and Y Vodovotz ldquoEffects of soy proteinisolate and egg white solids on the physicochemical propertiesof gluten-free breadrdquo Food Chemistry vol 129 no 1 pp 84ndash912011
[10] C Marco and C M Rosell ldquoRunctional and rheologicalproperties of protein enriched gluten free composite floursrdquoJournal of Food Engineering vol 88 pp 94ndash103 2008
[11] D Saglam P Venema R de Vries J Shi and E van der LindenldquoConcentrated whey protein particle dispersions heat stabilityand rheological propertiesrdquo Food Hydrocol vol 30 pp 100ndash1092013
[12] T D Hadnađev A Torbica and M Hadnađev ldquoRheologicalproperties of wheat flour substitutesalternative crops assessedby Mixolabrdquo Procedia Food Science vol 1 pp 328ndash334 2011
[13] W Chen andRHoseney ldquoDevelopment of an objectivemethodfor dough stickinessrdquo LWT-Food Sci Technol vol 28 pp 467ndash473 1995
[14] AACC ldquoApproved methods of the American Association ofCereal Chemistsrdquo inThe Amer Assoc Cereal Chem The AmerAssoc Cereal Chem Inc St Paul Minn USA 2000
[15] C M Rosell C Collar and M Haros ldquoAssessment of hydro-colloid effects on the thermo-mechanical properties of wheatusing the Mixolabrdquo Food Hydrocolloids vol 21 no 3 pp 452ndash462 2007
[16] J G Zadow ldquoMeasurement of the effect of whey proteinconcentrates on fermenting doughs by the Instron TesterrdquoAustralian Journal of Dairy Technology vol 36 pp 56ndash59 1981
[17] C C Kim and C E Walker ldquoChanges in starch pastingproperties due to sugars and emulsifiers as determined byviscosity measurementrdquo Journal of Food Science vol 57 pp1009ndash1013 1992
[18] C Marco and C M Rosell ldquoEffect of different protein isolatesand transglutaminase on rice flour propertiesrdquo Journal of FoodEngineering vol 84 pp 132ndash139 2008
[19] J Shim and S J Mulvaney ldquoEffect of heating temperature pHconcentration and starchwhey protein ratio on the viscoelasticproperties of corn starchwhey protein mixed gelsrdquo Journal ofthe Science of Food and Agriculture vol 81 pp 706ndash717 2001
[20] S F Dogan S Sahin and G Sumnu ldquoEffects of soy andrice flour addition on batter rheology and quality of deep-fatchicken nuggetsrdquo J Food Eng vol 71 pp 127ndash132 2005
[21] R C Hoseney and J Smewing ldquoInstrumental measurement ofstickiness of doughs and other foodsrdquo Journal of Texture Studiesvol 30 no 2 pp 123ndash136 1999
[22] MHeitmann E Zannini and E K Arendt ldquoImpact of differentbeer yeasts on wheat dough and bread quality parametersrdquoJournal of Cereal Science vol 63 pp 49ndash56 2015
[23] E J van Velzen J P van Duynhoven P Pudney P L Weegelsand J H van der Maas ldquoFactors associated with doughstickiness as sensed by attenuated total reflectance infraredspectroscopyrdquo Cereal Chem vol 80 pp 378ndash382 2003
[24] K Addo Y Xiong and S Blanchard ldquoThermal and dynamicrheological properties of wheat flour fractionsrdquo Food ResearchInternational vol 34 pp 329ndash335 2001
[25] J M Aguilera and E Rojas ldquoRheological thermal andmicrostructural properties of whey protein-cassava starch gelsrdquoJournal of Food Science vol 61 no 5 pp 962ndash966 1996
[26] H Yamamoto S TWorthington G Hou and P Ng ldquoRheologi-cal properties and baking qualities of selected soft wheats in theUnited Statesrdquo Cereal Chem vol 73 pp 215ndash221 1996
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
10 Journal of Food Quality
[27] S Barak DMudgil and B S Khatkar ldquoEffect of composition ofgluten proteins and dough rheological properties on the cooki-making qualityrdquoBritish Food Journal vol 115 pp 564ndash574 2013
[28] K HMcWatters ldquoCookie baking properties of defatted peanutsoybean and field pea floursrdquo Cereal Chem vol 55 pp 953ndash8631978
[29] B Singh M Bajaj S Sharma and J S Sidhu ldquoStudies on thedevelopment of high-protein biscuits from composite floursrdquoPlant Foods for Human Nutrition vol 43 pp 181ndash189 1993
[30] S Comfort and N K Howell ldquoGelation properties of soya andwhey protein isolate mixturesrdquo Food Hydrocolloids vol 16 no6 pp 661ndash672 2002
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Submit your manuscripts athttpswwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 201
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology