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Hydrocolloids in gluten-free breads: A review
ALEX A. ANTON & SUSAN D. ARTFIELD
Department of Food Science, Faculty of Agriculture & Food Science, University of Manitoba,
Winnipeg, MB, Canada
AbstractBread is a traditional food generally prepared from wheat flour. The main wheat componentresponsible for bread quality is gluten, which is an essential structure-binding protein. Althoughimportant, this protein can cause health problems in predisposed individuals, and is avoided inthe diet of celiac disease patients. As diagnosis methods are improved, revealing the highincidence of gluten-intolerance in the western world, the demand for novel, nutritious and high-quality gluten-free foods also ascends. However, for the production of gluten-free breads theabsence of gluten is critical and challenging in regards to the bread structure. Various gluten-free formulations have applied hydrocolloids to mimic the viscoelastic properties of gluten. Theycomprise a number of water-soluble polysaccharides with varied chemical structures providing arange of functional properties that make them suitable to this application. This paper reviewssome actual facts about celiac disease and focuses on the reported applications of hydrocolloidsin gluten-free breads.
Keywords: Celiac disease, hydrocolloids, gluten-free, bread
Introduction
Consumed since the early Egyptian era, bread is a staple food for the majority of the
world’s population (Samuel 1996). A variety of grains have been used for its
production; however, wheat is the most common in bread-making. This cereal
contains two proteins, glutenin and gliadin, which during mixing develop into gluten.
Gluten provides some unique functional properties in leavened breads, such as the
viscoelastic behavior of bread doughs. Moreover, gluten is responsible for the protein�starch interaction that is related to gas cell formation, including stabilization and
retention of the gas cells during the proofing and baking process (Gan et al. 1989).
Although important for the bread-making process, the presence of gluten may be an
issue for some individuals. In order to avoid the effects of an entheropathy (celiac
disease), a life-long intolerance to the gliadin fraction of wheat and the prolamins of
rye (secalins), barley (hordeins) and possibly oats (avidins), celiacs need a gluten-
restrictive diet (Campbell 1987; Murray 1999). This condition is characterized by the
damage to the mucous membrane of the small intestine, which results in poor
absorption of nutrients and, consequently, weight loss, diarrhea, anemia, fatigue,
flatulence, deficiency of folate and osteopenia (Blades 1997; Thompson 1997). The
Correspondence: Alex A. Anton, Department of Food Science, Faculty of Agriculture & Food Science,
University of Manitoba, Winnipeg, MB, Canada, R3T 2N2. Tel: 1 204 474 9621. Fax: 1 204 474 7630.
E-mail: [email protected]
ISSN 0963-7486 print/ISSN 1465-3478 online # 2008 Informa UK Ltd
DOI: 10.1080/09637480701625630
International Journal of Food Sciences and Nutrition,
February 2008; 59(1): 11�23
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manifestation of celiac disease, which culminates in intestinal mucosa damage, has
been reported to be the end result of three processes: genetic predisposition,
environmental factors and immunogically-based inflammation (Murray 1999). The
only effective treatment for such condition is a strict adherence to a gluten-free diet
throughout the patient’s lifetime. The total exclusion of gluten consumption results in
clinical and mucosal recovery (Gallagher et al. 2004).
The proposition of a diet for celiac people is not easy, since the most commonly
baked products, such as breads, cakes, biscuits, pizzas and pasta, are usually made out
of wheat flour and are consumed on an everyday basis by most people. The absence of
gluten results in major problems for bakers, and currently many gluten-free products
available on the market are of low quality, demonstrating poor mouthfeel and flavor
(Arendt et al. 2002).
For the production of gluten-free breads, a large number of flours, starches and
many substances such as enzymes, proteins and hydrocolloids have been applied to
mimic the viscoelastic properties of gluten (Gujral and Rosell 2004; Kim and De
Ruiter 1968; Sanchez et al. 2004; Toufeili at al. 1994). Hydrocolloids or gums
comprise a number of water-soluble polysaccharides with varied chemical structures
providing a range of functional properties that make them suitable for different
applications in the food industry (Rosell et al. 2007). Besides being applied as gluten-
substitutes in gluten-free breads, hydrocolloids have been used in foods to improve
texture, to slow down the starch retrodegradation, to increase moisture retention, and
to extend the overall quality of the product during time (Rojas et al. 1999).
Since gluten is the main structure-forming protein in flour and contributes to the
appearance and crumb structure of breads, its replacement is a major challenge to the
food scientist and technologist alike. Hence, the application of hydrocolloids in
gluten-free bread formulations appears to be a promising alternative for the
development of high-quality foods for a targeted public. This review discusses some
actual facts about the celiac disease and the current issues regarding the development
of gluten-free formulations, as well as focusing on the reported applications of
hydrocolloids in gluten-free breads.
The gluten-free market: From history to the supermarket shelf
The classic description of celiac disease was reported more than 100 years ago by
Samuel Gee, in 1888, as a ‘celiac disorder’. In this description, Gee related the
following characteristics: ‘chronic indigestion found in people of all ages, especially in
children between one and five years of age’ (Auricchio and Troncone 1996). However,
it was during the Second World War that the deleterious effects of some cereals were
associated with celiac disease. In this period, Dicke, a Dutch pediatrician, observed
that during the time of wheat scarcity the occurrence of ‘celiac sprue’ had diminished
substantially. Afterwards, when the Swedish planes brought bread to Holland, the
celiac children quickly manifested the disease symptoms, confirming the importance
of wheat on the disease genesis (Berge-Henegouwen and Mulder 1993).
Epidemiological studies in 1950 first estimated a relatively low incidence of celiac
disease. However, by the 1960s more specific tests had became available, and it is now
possible to determine accurately its true prevalence (Auricchio and Troncone 1996).
While a biopsy remains the definitive test, antigliadin antibody serological tests have
resulted in substantially increased diagnosis rates (Sdepanian et al. 1999).
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In the 1980s some studies from Great Britain and Ireland (Challacombe and Baylis
1980; Stevens et al. 1987) observed a decrease in the incidence of celiac disease when
gluten was delayed being introduced into the diet. However, in the 1990s
epidemiological observations showed a high prevalence of such a disease in apparently
healthy children (Catassi et al. 1994, 1995) and adults (Grodzinsky et al. 1992). In
1994, an epidemiological study conducted in an Italian province (Catassi et al. 1994)
demonstrated that the celiac disease prevalence in that population was in the rate of
one in 300 studied individuals. Subsequently, an Italian multicentric study observed
that the Italian prevalence was actually one in 184 (Catassi et al. 1996).
Today, the iceberg model is suggested to explain the prevalence of celiac disease
(Feighery 1999), which can be conceived as the overall size of the iceberg. Diagnosed
cases make up the visible part of the iceberg, representing around 10% of the whole
celiac population. Bellow the waterline the group of ‘silent’ cases is found (75%),
which corresponds to people who have not yet been identified and have flat small
intestinal mucosa. This group may remain undiagnosed because the condition has no
symptoms, or the symptoms have not yet been linked to celiac disease. Occupying the
bottom of the iceberg (15%), there is a small group with latent celiac disease. That is,
they show a normal mucosa while taking gluten, yet still have the potential to manifest
the disease (Feighery 1999).
In Canada, according to the Canadian Celiac Association (Celiac Disease, 2007),
the public demand for gluten-free products is quite large. Although statistics are not
readily available, it is estimated that one in 133 persons are affected by celiac disease.
Until recently, the disease was considered less common in North America than in
Europe. However, in a recent multicenter study in the United States a prevalence of
celiac disease of one in 133 in the general population was reported (Fasano et al.
2003). Prevalence among first-degree and second-degree relatives of patients with
celiac disease was one in 22 and one in 39, respectively, and that of symptomatic
patients was one in 56. Although celiac disease is now recognized as one of the most
common disorders in Europe, North and Latin America, it seems to remain as one of
the most underdiagnosed (Cranney et al. 2007; Sdepanian et al. 1999).
In the Canadian Celiac Health Survey (Cranney et al. 2007), 90% of the
interviewed patients described their diets as strictly gluten-free. Also, 81% of
respondents declared they avoided going to restaurants, 38% avoided traveling
some or most of the time and 94% brought gluten-free foods with them when
traveling. When asked about two factors that would contribute most to improving the
lives of celiac individuals, the respondents identified earlier diagnosis (60.5%) and
better labeling of gluten-containing foods (52%).
Considering the importance of labeling in the life quality of celiac patients, in 1976 the
Codex Alimentarius Commission of the World Health Organization (Geneva) and the
Food and Agricultural Organization (Rome) adopted The Codex Standard for gluten-
free foods. In 1981 and in 2000, draft-revised standards attested that so-called ‘gluten-
free foods’ are described as: (a) consisting of, or made only from ingredients that do not
contain any prolamins from wheat or all Triticum species such as spelt, kamut or durum
wheat, rye, barley, oats or their crossbred varieties with a gluten level not exceeding 20
ppm; or (b) consisting of ingredients from wheat, rye, barley, oats, spelt or their
crossbred varieties, which have been rendered gluten-free, with a gluten level not
exceeding 200 ppm; or (c) any mixture of two ingredients as in (a) and (b) mentioned
with a level not exceeding 200 ppm (Codex Alimentarius 2007a, Gallagher et al. 2004).
Hydrocolloids in gluten-free breads 13
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However, there are conflicts in labeling foods ‘gluten-free’ because the exact
amount of prolamins that celiac individuals may consume without damaging the
mucosa has not been scientifically determined. It had been thought that the protein
component in wheat starch could be completely removed, but it is now known that
some protein will remain. In the United States and Canada, gluten-free diets are
devoid of any wheat starch, and are based on naturally gluten-free ingredients such as
rice (Gallagher et al. 2004).
Based on the Canada’s Food Guide to Healthy Eating (adapted for gluten-free
diets) (Case 2006), bread is in the most consumed foods category and is a main
component of the breakfast (Celiac Disease 2007). However, the manufacture of
bread from gluten-free flours is considered technologically critical. The absence of
gluten has an impact on cell formation, crumb and crust characteristics, volume,
porosity and many quality parameters (Sivaramakrishnan et al. 2004).
Nonetheless, in 1954 Rotsch reported that substances that swell in water have the
ability to replace gluten in the dough. Since then, diverse approaches to replace gluten
and produce highly acceptable gluten-free breads have been performed. Among the
ingredients applied in gluten-free breads, the use of starches, hydrocolloids, and novel
attempts such as enzymes, appear as promising alternatives.
Hydrocolloids
The use of additives has recently become common practice in the baking industry.
They are applied to improve dough handling properties, enhance the quality of fresh
bread and extend the shelf-life of stored bread. Within these targets, a large array of
additives with different chemical structures is used, including enzymes, synthetic
antioxidants and conservatives.
A different class of additives extensively used in the food industry is the
hydrocolloids. These compounds, commonly named gums, are capable of controlling
both the rheology and texture of aqueous systems throughout the stabilization of
emulsions, suspensions and foams (Diezak 1991). They comprise diverse water-
soluble polysaccharides with different chemical structures providing a range of
functional properties that make them widely used in the food industry. Hydrocolloids
are able to modify starch gelatinization (Rojas et al. 1999), and to extend the overall
quality of the product over time. In addition, some studies have reported the use of
hydrocolloids as fat replacements (Lucca and Trepper 1994).
All hydrocolloids interact with water, reducing its diffusion and stabilizing its
presence. Generally neutral hydrocolloids are less soluble whereas polyelectrolytes are
more soluble, but the hydration kinetics depend on many factors; xanthan, guar and
carboxymethylcellulose (CMC) are soluble in cold water but carrageenan, locust bean
gum and many alginates require hot water for complete hydration. Water may be held
specifically through direct hydrogen bonding or structuring of water or within
extensive but contained inter-molecular and intra-molecular voids. Interactions
between hydrocolloids and water depend on hydrogen bonding and therefore on
temperature and pressure in the same way as water cluster formation. Similarly, there
is a reversible balance between entropy loss and enthalpy gain, but the process may be
kinetically limited and optimum networks may never be achieved. Hydrocolloids may
exhibit a wide range of conformations in solution as the links along the polymeric
chains can rotate relatively freely within valleys in the potential energy landscapes.
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Large, conformationally stiff hydrocolloids present essentially static surfaces encoura-
ging extensive structuring in the surrounding water. Water binding affects the texture
and processing characteristics, prevents syneresis and may have substantial eco-
nomical benefit. In particular, hydrocolloids can provide water for increasing the
flexibility (plasticizing) of other food components. They can also affect ice-crystal
formation and growth, thus exerting a particular influence on the texture of frozen
foods. Some hydrocolloids, such as locust bean gum and xanthan gum, may form
stronger gels following a freeze�thaw cycle due to kinetically irreversible changes
resulting from forced association as water is removed (as ice) on freezing (Giannouli
and Morris 2003).
As hydrocolloids can dramatically affect the flow behavior when present at low
concentrations, most of them are used to increase viscosity, which leads to
stabilization of foodstuffs by preventing settling, phase separation, foam collapse
and crystallization. Viscosity generally changes with concentration, temperature and
shear strain rate in a complex manner dependent on the hydrocolloid(s) and other
materials present; mixtures of hydrocolloids may act synergically to increase viscosity,
or antagonistically to reduce it (Marcotte et al. 2001).
There is an increasing demand for hydrocolloids in the bakery industry, where they
have been utilized for diverse purposes. Guar gum has been employed for improving
the volume and texture of frozen dough bread (Ribotta et al. 2004b), while the
employment of hydroxypropylmethylcellulose (HPMC) has resulted in soft bread-
crumb loaves with higher specific bread volume, improved sensory characteristics and
an extended shelf-life (Barcenas and Rosell 2005; Collar et al. 1998). Similar behavior
has been reported for HPMC when it was studied in the performance of bread stored
at sub-zero temperatures (Barcenas and Rosell 2006). Xanthan gum, HPMC and
other hydrocolloids have been tested for their potential as bread improvers and anti-
staling agents (Guarda et al. 2004). In their investigation, all of these hydrocolloids
were able to decrease the loss of moisture content during storage and to reduce the
dehydration rate, consequently retarding the crumb hardening (Rosell et al. 2007).
Mechanistically, the macroscopic effect of hydrocolloids on wheat dough has been
discussed by structural changes induced in the main components of wheat flour.
However, there is currently no general consensus about the mechanism of action of
hydrocolloids. Illustrating this fact, CMC has been reported to be bound preferen-
tially to the gluten structure, causing a displacement of the lipids bounded to gluten.
Nonetheless, HPMC was described as bound to the external part of the starch
granules, reflecting a displacement of the lipids bounded to starch (Collar et al. 1998).
Other microstructural studies of the breadcrumbs also revealed possible interactions
between HPMC and the bread constituents, suggesting that this hydrocolloid could
involve all the bread constituents and block internal interactions (Barcenas and Rosell
2005). Conversely, ionic interactions have been detected between charged hydro-
colloids like carrageenan and high methoxyl pectin, explaining the formation of
hydrophilic complexes with the gluten proteins (Ribotta et al. 2005). Thus,
hydrocolloids in regular breads could interfere either in the starch�gluten interactions
or in the formation of physical entanglements (Rosell et al. 2007).
The legal status of hydrocolloids is controlled by health authorities, as is the case of
many other food additives. The extent to which hydrocolloids may be used in food,
and the maximum dosage permitted, may vary considerably among their different
types and according to the country. International organizations such as the Food and
Hydrocolloids in gluten-free breads 15
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Agricultural Organization/World Health Organization Codex Alimentarius Commis-
sion are seeking to harmonize regulations for the use of hydrocolloids, but differences
still exist. Therefore, relevant legislation should be consulted before using hydro-
colloids in processed foods.
The Food and Agricultural Organization/World Health Organization Expert
Committee on Food Additives has given the acceptable daily intake classification
‘not specified’ for some hydrocolloids, such as CMC, HPMC, pectin, guar gum,
locust bean gum, carrageenan and xantham gum. In this sense, ‘not specified’ means
that, on the basis of the available data (chemical, biochemical, toxicological and
other), the total daily intake of the substance, arising from its use at the levels
necessary to achieve the desired effect and from its acceptable background in food,
does not, in the opinion of the Committee, represent a hazard to health. For this
reason, and for the reasons stated in the individual evaluations, the establishment of
an acceptable daily intake is not deemed necessary (Codex Alimentarius 2007).
In Canada, the Food and Drugs Act and Regulations demands ‘Good Manufactur-
ing Practice’ for the application of guar gum, CMC, HPMC, pectin and xantham,
among others, in bakery goods, which are listed as ‘unstandardized foods’ (Canadian
Legislation 2007). Thus, these hydrocolloids could be safely and legally applied in
gluten-free bread recipes.
Hydrocolloids in gluten-free breads
Since Rotsch (1954) demonstrated the potential of substances that swell in water to
mimic the gluten properties in dough, and Kulp et al. (1974) reported the
incorporation of xanthan gum in the production of a pure wheat-starch bread, the
use of hydrocolloids in gluten-free breads has been increasing.
In 1976, Nishita and co-workers reported the development of a yeast-leavened rice-
bread formula using different additives. They found that hydrocolloids, in particular
HPMC, were the only additives capable of providing the dough with the viscosity
necessary to trap fermentation gases, and the ‘water-release’ effect necessary for starch
gelatinization during baking. The use of HPMC leaded to the development of a rigid,
yet porous cell structure and good loaf volume. Plastic fats and surfactants, which
normally improve wheat bread quality, had the opposite effect in rice breads. Refined
vegetable oils produced satisfactory volumes, grain and texture. Initial taste panel
evaluations showed that less than one-half of the taste judges accepted the bread.
However, when the product was identified as a gluten-free rice bread, more than one-
half (19 out of 31) of the taste panel members gave a score of five or higher on a
hedonic scale of nine.
The addition of hydrocolloids as binding agents and gluten substitutes in bread
made from corn starch has been reported (Acs et al. 1997). In their study, the bread
volume and firmness were evaluated to investigate the technological effect of xanthan,
guar gum, locust bean gum and tragant. The authors showed these agents could be
efficiently assigned in substituting the technological effect of gluten in gluten-free
systems, resulting in a highly significant increase in bread volume and loosening of
the crumb (PB0.001). Regarding the effects of the individual gums, the difference
among them was significant, where the highest quality bread was the one containing
xanthan. Also in 1997, the use of HPMC was reported to be the most appropriate for
best rice bread volume expansion among several gums (Kang et al. 1997). This study
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verified the feasibility of the application of HPMC, locust bean gum, guar gum,
carageenan, xantham gum and agar on the improvement of rice bread.
The effects of a mixture of hydrocolloids in gluten-free breads were studied by
Gambus et al. (2001). The quality of the breads made mainly with potato starch, corn
starch and corn flour and added pectin, guar gum or their 1:1 mixture were compared.
It was found that loaves containing guar gum produced better quality in comparison
with those of added pectin in regards to volume, moisture content of crumb, baking
efficiency and oven loss. However, the use of a guar gum and pectin mixture in a 1:1
ratio allowed elimination of unwanted texture features of breads that resulted when
one single hydrocolloid was added. In this sense, characteristics such as reduced
gumminess and chewiness of guar breads, and excessive crispiness and low resilience
of pectin breads, were eliminated. In addition, the bread with the mixture of guar gum
and pectin showed the lowest hardness and the extent of gelatinization in the guar gum
breads was reduced by partial replacement of this hydrocolloid by pectin, which
positively decreased crumb hardening without affecting the moisture content.
Likewise, HPMC and CMC have been reported to work as better gluten replacers
than guar gum in gluten-containing breads made out of composite flours (50:50 wheat
flour:rice flour) (Gan et al. 2001). They found that HPMC at 1.7% and CMC at
0.4% gave higher quality parameters than guar gum at 0.7%. Subsequently, Cato et al.
(2001) reported that for the production of high-quality rice flour breads a
combination of CMC at 0.8% and HPMC at 3.3% should be applied.
Through differential scanning calorimetry, the thermal performance of a bread
dough consisting of a blend of non-allergenic corn and cassava starches with HPMC
as gluten mimetic hydrocolloid in conjunction with egg white was studied (Kobylanski
et al. 2004). The outcomes were analyzed using response surface methodology and
the authors concluded that this approach could be well applied to a complex system
such as a gluten-free dough. In this context, the effect of each of the components
on the thermal behavior of the dough and the interactions between them could
be revealed. Hence, the group found that the level of water, HPMC and egg white
addition to the dough greatly influenced the transition temperatures. The effect of the
hydrocolloid studied on the onset temperature of starch gelatinization was dependent
on the interactions between HPMC and water.
In a combination of rice flour, corn starch and cassava starch (45%, 35% and 20%)
a highly acceptable gluten-free bread has been produced (Lopez et al. 2004). In this
formulation the authors applied xantham gum at 0.5%, and characteristics such as a
crumb formed by uniformed and well distributed cells, pleasant flavor and appearance
were achieved. Similarly, Cato et al. (2004) studied loaf breads made with rice flour
and potato starch, to which HPMC, guar gum and CMC had been added, and
compared them with breads containing wheat/rice mixtures. Evaluating the loaf
volume, texture and crust and crumb color, they reported that HPMC had the most
favorable effect on bread qualities, whereas CMC had little effect and guar gum had
no effect whatsoever. They also showed that the combination of HPMC and CMC
was the best in regards to dough viscoelastic properties. With such a mixture they
could achieve a dough able to trap fermented gases and to develop a rigid but porous
cell structure, as well as good loaf volume. The positive effects of HPMC on
rheological properties of rice dough and rice bread have indicated favorable
perspectives for the gluten-free bread manufactures (Sivaramakrishnan et al. 2004).
In their investigation, the rheological measurements from oscillation tests and creep
Hydrocolloids in gluten-free breads 17
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tests showed that the rice dough with 1.5% and 3.0% HPMC had similar rheological
properties to that of wheat flour dough. Therefore, the authors concluded the
suitability of rice flour for the production of acceptable breads. Furthermore,
confirming the favorable effect of HPMC on the quality of rice bread, Lee and
Lee (2006) verified that the addition of 3.5% of such hydrocolloid decreased crumb
hardness of fresh and stored breads.
The textural comparisons of gluten-free and wheat-based doughs, batters and
breads containing xantham gum (1.25%) or xantham (0.9%) plus konjac gum (1.5%)
have been performed (Moore et al. 2004). It was reported that, regardless of the
addition of hydrocolloids, all gluten-free breads were brittle after 2 days of storage,
detectable by the occurrence of fracture, and the decrease in springiness, cohesiveness
and resilience derived from texture profile analysis. Nonetheless, the authors verified
the incorporation of dairy-based proteins in the formulations and concluded that the
formation of a continuous protein phase is critical for an improved keeping quality of
gluten-free breads.
Other alternative ingredients have been employed in gluten-free breads formula-
tions. The incorporation of soybean flour in mixtures of rice flour and cassava flour
containing gelatin (0.5%) appears to be promising (Ribotta et al. 2004a). Similarly,
Schober et al. (2005) tested the quality differences among sorghum hybrids in the
quality parameters of gluten-free breads made from this cereal. Using xantham gum
(0.3�1.2%) and response surface methodology, they observed that increasing
hydrocolloid levels would cause a decrease in the loaf specific volumes. Consequently,
they attested that xantham gum had negative effects on crumb structure of sorghum
breads and that, with the addition of corn starches, their textural aspects could
possibly be better improved.
The microstructure analysis of gluten-free breads regarding the staling process and
its correlation with sensory and mechanical properties has shown the beneficial effects
of hydrocolloids (Ahlborn et al. 2005). Using scanning electron microscopy, this study
demonstrated that the formulation containing rice, egg and milk proteins, xantham
gum, and HPMC created a continuous matrix with starch fragments. Hence, the
addition of these hydrocolloids resulted in a structure similar to gluten. Moreover, the
gluten-free rice bread had the highest sensory scores for both moistness and freshness,
which was probably due to the xantham and HPMC water-retention properties.
Using response surface methodology, McCarthy et al. (2005) optimized a gluten-
free bread formulation primarily based on rice flour, potato starch and skim milk
powder applying varied levels of HPMC and water. Response surface methodology is
a statistical technique reported to be useful in the development and optimization of
cereal products (Toufeili et al. 1994; Gallagher et al. 2003). In this study, the authors
observed significant interactions between the hydrocolloid and water with regards to
cell formation and structure. Optimal ingredient levels were determined on the basis
of statistical modeling and the optimized formulation contained 2.2% HPMC and
79% water flour/starch base.
Aiming to add prebiotic compounds to a corn and potato starch bread, Korus et al.
(2006) demonstrated the influence of inulin and fructooligosaccharides on this bread’s
quality. The levels of these prebiotics ranged from 3.5% to 8% and all the
formulations contained guar gum (1.5%) and pectin (1.5%). Although the authors
did not specifically discuss the influence of hydrocolloids, they showed the possibility
of obtaining good quality gluten-free bread supplemented with prebiotics when
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hydrocolloids were part of the formula. Among the tested prebiotics, the most
beneficial in terms of bread quality was found for a 5% addition of inulin.
Following a similar attempt to increase the dietary fiber content of gluten-free
breads, novel ingredients such as b-glucan have been employed as hydrocolloids
(Lazaridou et al. 2007). Together with pectin, CMC, agarose and xanthan, the effects
of b-glucan were studied at levels of 1% and 2% on the dough rheology and bread
quality parameters of a formulation containing rice flour, corn starch and sodium
caseinate. Despite showing that b-glucan did not behave as well as the other
hydrocolloids, the authors confirmed the potential of xanthan, pectin and CMC as
gluten replacers.
Another novel approach to improve the structure of gluten-free breads was the
application of transglutaminase, an enzyme that catalyzes acyl-transfer reactions
through which proteins can be cross-linked (Moore et al. 2006). This study evaluated
the impact of transglutaminase at levels of 0�10 units enzyme/g protein on the bake
loss, specific volume, color, texture, image characteristics and total moisture of gluten-
free breads. The breads were formulated based on rice flour, potato starch, corn flour,
different protein sources at varied levels (skim milk powder, soya flour and egg
powder) and xantham gum at 1%. Analyzing network formation through confocal
laser-scanning microscopy and the other quality parameters, the authors concluded
the possibility of forming a protein network in gluten-free bread with the addition of
transglutaminase. It had also been noted that the enzyme efficiency was dependent on
both the protein source and the level of enzyme concentration.
Observations and future perspectives
Several hydrocolloids have been applied in gluten-free breads (Table I). Among all,
xanthan gum and HPMC appear to be the best in mimicking the gluten properties,
and therefore are the most used.
Xanthan gum is an exocellular heteropolysaccharide produced by the microorgan-
ism Xanthomonas campestris by a fermentation process. Lazaridou et al. (2007)
discussed the improvement of viscoelastic properties of gluten-free dough by
incorporation of different hydrocolloids, where xanthan exhibited the best perfor-
mance. It was showed that the magnitude of influence of hydrocolloids on rheological
properties of gluten-free dough was possibly related to the molecular structure and
chain conformation of the polysaccharide that determine the physical intermolecular
associations (cross-links or entanglements) of the polymeric chains. In this context,
xanthan showed the lowest creep compliance values and the highest zero shear
viscosity among CMC, pectin, agarose and b-glucan. Xanthan also exhibited the most
enhanced elastic properties, probably due to its weak gel properties and high viscosity
values at low shear rates.
On the other hand, HPMC is a cellulose ether derived from alkali-treated cellulose
that is reacted with methyl chloride and propylene oxide. Its particular properties
seem to be related to its affinity for both the aqueous and nonaqueous phases of the
dough system, therefore maintaining uniformity and stability (McCarthy et al. 2005).
Moreover, it has been reported that in gluten-free breads HPMC leads to starch
granules to adhere to one another changing their mobility (Sivaramakrishnan et al.
2004). This effect would cause a change in the bread cell structure, and the system as
a whole would have more space to entrap more water. Also, the onset temperature of
Hydrocolloids in gluten-free breads 19
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starch gelatinization has been related to HPMC�water interactions (Kobylanski et al.
2004). These authors observed that gelation of HPMC could promote phase
separation between starch and HPMC gel with the consequence of restricting swelling
of starch granules and delaying the initiation of gelatinization because gel phase might
be expected to limit water migration from one granule to another. Additionally, they
discussed possible interactions of hydroxyl groups of HPMC with starch that could
contribute to facilitate the gelatinization.
While hydrocolloids demonstrate successful application in gluten-free bread formu-
lations, the enrichment of gluten-free bakery goods with dietary fibers has proven
necessary. According to the literature, celiac individuals have generally a low intake of
fibers due to their gluten-free diet (Thompson 2000). From this perspective, the in-
corporation of dietary fiber in gluten-free breads appears to be a promising approach.
Although dietary fiber itself or prebiotics cannot replace hydrocolloids in gluten-free
formulations (Korus et al. 2006; Lazaridou et al. 2007), they could certainly enhance
their nutritional profile. Thus, alternative gluten-free flours or isolated fibers should
be studied in regards to their feasibility for the production of high nutritious gluten-
free goods.
Table I. Summary of studies involving gluten-free breads and hydrocolloids.
Bread main ingredients Hydrocolloids Reference
Wheat starch Xantham gum Kulp et al. (1974)
Rice flour HPMC, guar gum Nishita et al. (1976)
Corn starch Xantham gum, guar gum,
locust bean gum
Acs et al. (1997)
Rice flour HPMC, locust bean gum, guar gum,
carageenan, xantham gum
Kang et al. (1997)
Potato starch, corn starch,
corn flour
Pectin, guar gum Gambus et al. (2001)
Wheat flour, rice flour HPMC, CMC, guar gum Cato et al. (2001)
Rice flour HPMC, CMC Gan et al. (2001)
Rice flour, potato starch HPMC, CMC, guar gum Cato et al. (2004)
Corn starch, cassava starch HPMC Kobylanski et al. (2004)
Rice flour, corn starch,
cassava starch
Xantham gum Lopez et al. (2004)
Rice flour, dairy-based proteins Xantham gum, konjac gum Moore et al. (2004)
Rice flour, cassava flour,
soybean flour
Gelatin Ribotta et al. (2004a)
Rice flour HPMC Sivaramakrishnan et al.
(2004)
Rice flour, milk proteins,
egg proteins
Xantham gum, HPMC Ahlborn et al. (2005)
Rice flour, potato starch,
skim milk
HPMC McCarthy et al. (2005)
Sorghum Xantham Schober et al. (2005)
Corn starch, potato starch,
inulin, fructooligosaccharides
Guar gum, pectin Korus et al. (2006)
Rice flour HPMC Lee and Lee (2006)
Rice flour, potato starch,
corn flour
Xantham gum Moore et al. (2006)
Rice flour, corn starch,
sodium caseinate
CMC, pectin, agarose,
xantham gum, b-glucan
Lazaridou et al. (2007)
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Considering the nutritional and economical aspects of legumes (Tharanathan and
Mahadevamma 2003), it is suggested that flours made from seeds such as peas, beans,
lentils and chickpeas are added to traditional recipes. However, this attempt would
surely affect the quality properties of an established gluten-free recipe, an issue that
could certainly be minimized by the addition of combined hydrocolloids and enzymes.
Additionally, starches and dietary fiber isolated from pulse legumes could possibly
bring a new perspective in the production of such products.
Conclusion
Novel diagnosis methods and recent epidemiological observations have revealed the
incidence of celiac disease in the western world, as alternative approaches to improve
the quality of life of these patients have been suggested. Among diverse practices,
better labeling of gluten-containing foods and the expansion of the gluten-free foods
portfolio are certainly valid. Hence, given the importance of bread as an essential diet
item, the research and development of highly acceptable and nutritious gluten-free
breads is a challenging and emerging area for food scientists.
Based on successful reported applications of hydrocolloids and its legal and safe
status, it is suggested that novel nutritious ingredients, combined with hydrocolloids
and possibly enzymes, can be added to traditional and well-established gluten-free
bread recipes. Among the various hydrocolloids reported, HPMC and xantham gum
appear to be the most promising in regards to water retention and the quality of the
final product.
References
Acs E, Kovacs Z, Matuz J. 1997. Possibilities of producing low-protein, gluten-free bread. 1. Structure
formation. Novenytermeles 46:227�234.
Ahlborn GJ, Pike OA, Hendrix SB, Hess WM, Huber CS. 2005. Sensory, mechanical, and microscopic
evaluation of staling in low-protein and gluten-free breads. Cereal Chem 82:328�335.
Arendt EK, O’Brien CM, Schober T, Gormley TR, Gallagher E. 2002. Development of gluten-free cereal
products. Farm Food 12:21�27.
Auricchio S, Troncone R. 1996. History of celiac disease. Eur J Pediatr 155:427�428.
Barcenas ME, Rosell CM. 2005. Effect of HPMC addition on the microstructure, quality and aging of
wheat bread. Food Hydrocoll 19:1037�1043.
Barcenas ME, Rosell CM. 2006. Different approaches for improving the quality and extending the shelf life
of the partially baked bread: Low temperatures and HPMC addition. J Food Eng 72:92�99.
Berge-Henegouwen GP, Mulder CJJ. 1993. Pioneer in the gluten-free diet: Wille-Karel Dicke 1905�1962,
over 50 years of gluten-free diet. Gut 34:1473�1475.
Blades M. 1997. Food allergies and intolerances: An update. Nutr Food Sci 4:146�151.
Campbell JA. 1987. Diet therapy of celiac disease and dermatitis herpetiformis. World Rev Nutr Diet
51:189�223.
Health Canada. 2007. Canadian Legislation. Available online at: http://www.hc-sc.gc.ca/fn-an/alt_formats/
hpfb-dgpsa/pdf/legislation/e_c-tables.pdf (accessed 1 March 2007).
Case S. 2006. Gluten-free diet: A comprehensive resource guide. Toronto, ON: Case Nutrition Consulting.
Catassi C, Ratsch IM, Fabiani E, Rossini M, Bbordicchia F, Candela F, Coppa GV, Giorgi PL. 1994.
Coeliac disease in the year 2000: Exploring the iceberg. Lancet 343:200�203.
Catassi C, Ratsch IM, Fabiani E, Ricci S, Bordicchia F, Pierdomenico R. 1995. High prevalence of
undiagnosed celiac disease in 5280 Italian students screened by antigliadin antibodies. Acta Paediatr
84:572�576.
Catassi C, Fabiani E, Ratsch IM, Coppa GV, Giorgi PL, Pierdomenico R, Alessandrini S, Iwanejko G,
Domenici R, Mei E, et al. 1996. The celiac iceberg in Italy. A multicentre antigliadin antibodies screening
for celiac disease in school age subjects. Acta Paediatr 85:29�35.
Hydrocolloids in gluten-free breads 21
Int J
Foo
d Sc
i Nut
r D
ownl
oade
d fr
om in
form
ahea
lthca
re.c
om b
y U
B d
er L
MU
Mue
nche
n on
03/
18/1
3Fo
r pe
rson
al u
se o
nly.
Page 12
Cato L, Gan JJ, Rafael LGB, Small DM. 2004. Gluten free breads using rice flour and hydrocolloid gums.
Food Aust 56:75�78.
Cato L, Rafael LGB, Gan J, Small DM. 2001. The use of rice flour and hydrocolloid gums for gluten-free
breads. In: Cereals 2001. Proceedings of the 51st Australian Cereal Chemistry Conference, 9�13, Sept,
2001, Cooge, New South Wales, Australia. Eds, Wooton M, Batey IL, Wrigley CW. pp 304�308.
Werribee, Australia: Royal Australian Chemical Institute.
Canadian Celiac Association. 2007. Celiac Disease. Available online at: http://www.celiac.ca/EnglishCCA/
eceliac.html (accessed 20 February 2007).
Challacombe DN, Baylis JM. 1980. Childhood celiac disease is disappearing. Lancet 2:1359�1360.
Codex Alimentarius. 2007a. Draft revised standard for gluten-free foods (CODEX STAN 118-1981,
amended 1983) at step 6 of the procedure. Available online at: ftp://ftp.fao.org/codex/Circular_Letters/
CXCL 2006/c106_05e.pdf (accessed 2 March 2007).
Collar C, Armero E, Martinez JC. 1998. Lipid biding of formula bread doughs. Zeitschr Lebensmitt-
Untersuch Forsch 207:110�121.
Cranney A, Zarkadas M, Graham ID, Butzner JD, Rashid M, Warren R, Molloy M, Case S, Burrows V.
2007. The Canadian celiac health survey. Dig Dis Sci 52:1087�1095.
Diezak JD. 1991. A focus on gums. Food Technol 45:116�132.
Fasano A, Berti I, Gerdarduzzi T, Not T, Colletti RB, Drago S, Elitsur Y, Green PH, Guandalini S, Hill ID,
et al. 2003. Prevalence of celiac disease in at-risk and not-at-risk groups in the United States: A large
multicenter study. Arch Internal Med 163:286�292.
Feighery CF. 1999. Coeliac disease. Br Med J 319:236�239.
Gallagher E, O’Brien CM, Scannell AGM, Arendt EK. 2003. Use of response surface methodology to
produce functional short dough biscuits. J Food Eng 56:269�271.
Gallagher E, Gormley TR, Arendt EK. 2004. Recent advances in the formulation of gluten-free cereal-
based products. Trends Food Sci Technol 15:143�152.
Gambus H, Nowotna A, Ziobro R, Gumul D, Sikora M. 2001. The effect of use of guar gum with pectin
mixture in gluten-free bread. Electron J Polish Agric Univ 4:1�13.
Gan Z, Ellis PR, Vaughn JG, Gallard T. 1989. Some effects of non-endosperm components of wheat and of
added gluten on whole-meal bread microstructure. J Cereal Sci 10:81�91.
Gan J, Rafael LGB, Cato L, Small DM. 2001. Evaluation of the potential of different rice flours in bakery
formulations. In: Cereals 2001. Proceedings of the 51st Australian Cereal Chemistry Conference,
9�13 Sept, 2001, Coogee, New South Wales, Australia. Eds, Wooton M, Batey IL, Wrigley CW. pp
309�312. Werribee, Australia: Royal Australian Chemical Institute.
Giannouli P, Morris ER. 2003. Cryogelation of xanthan. Food Hydrocoll 17:495�501.
Grodzinsky E, Franzen L, Hed J, Strom M. 1992. High prevalence of celiac disease in healthy adults
revealed by antigliadin antibodies. Ann Allergy 69:66�70.
Guarda A, Rosell CM, Benedito C, Galotto MJ. 2004. Different hydrocolloids as bread improvers and
antistaling agents. Food Hydrocoll 18:214�247.
Gujral HS, Rosell CM. 2004. Improvement of the breadmaking quality of rice by glucose oxidase. Food Res
Int 37:75�81.
Kang MY, Choi YH, Choi HC. 1997. Effects of gums, fats and glutens adding on processing and quality of
milled rice bread. Kor J Food Sci Technol 29:700�704.
Kim J, De Ruiter D. 1968. Bread from non-wheat flours. Food Technol 22:867�878.
Kobylanski JR, Perez OE, Pilosof AMR. 2004. Thermal transitions of gluten-free doughs as affected by
water, egg white and hydroxypropylmethylcellulose. Thermochim Acta 411:81�89.
Korus J, Grzelak K, Achremowicz K, Sabat R. 2006. Influence of prebiotic additions on the quality
of gluten-free bread and on the content of inulin and fructooligosaccharides. Food Sci Technol Int
12:489�495.
Kulp K, Frank NH, Thomas AL. 1974. Preparation of bread without gluten. Baker’s. Dig 48:34�38.
Lazaridou A, Duta D, Papageorgiou M, Belc N, Biliaderis CG. 2007. Effects of hydrocolloids on dough
rheology and bread quality parameters in gluten-free formulations. J Food Eng 79:1033�1047.
Lee M, Lee Y. 2006. Properties of gluten-free rice breads using different rice flours prepared by dry, wet and
semi-wet milling. Food Eng Progr 10:180�185.
Lopez ACB, Pereira AJG, Junqueira RG. 2004. Flour mixture of rice flour, corn and cassava starch in the
production of gluten-free white bread. Braz Arch Biol Technol 47:63�70.
Lucca PA, Trepper BJ. 1994. Fat replacers and the functionality of fat in foods. Trends Food Sci Technol
5:12�19.
22 A. A. Anton & S. D. Artfield
Int J
Foo
d Sc
i Nut
r D
ownl
oade
d fr
om in
form
ahea
lthca
re.c
om b
y U
B d
er L
MU
Mue
nche
n on
03/
18/1
3Fo
r pe
rson
al u
se o
nly.
Page 13
Marcotte M, Taherian ARH, Ramaswamy HS. 2001. Rheological properties of selected hydrocolloids as a
function of concentration and temperature. Food Res Int 34:695�703.
McCarthy DF, Gallagher E, Gormley TR, Schorber TJ, Arendt EK. 2005. Application of response surface
methodology in the development of gluten-free bread. Cereal Chem 82:609�615.
Moore MM, Schober TJ, Dockery P, Arendt EK. 2004. Textural comparisons of gluten-free and wheat-
based doughs, batters, and breads. Cereal Chem 84:567�575.
Moore MM, Heinbockel M, Dockery P, Ulmer HM, Arendt EK. 2006. Network formation in gluten-free
bread with application of transglutaminase. Cereal Chem 83:28�36.
Murray JA. 1999. The widening spectrum of celiac disease. Am J Clin Nutr 69:354�365.
Nishita KD, Roberts RL, Bean MM, Kennedy BM. 1976. Development of a yeast-leavened rice-bread
formula. Cereal Chem 53:626�635.
Ribotta PD, Ausar SF, Morcillo MH, Perez GT, Beltramo DM, Leon AE. 2004a. Production of gluten-free
bread using soybean flour. J Sci Food Agric 84:1969�1974.
Ribotta PD, Perez GT, Leon AE, Anon MC. 2004b. Effect of emulsifier and guar gum on micro structural,
rheological and baking performance of frozen bread dough. Food Hydrocoll 18:305�313.
Ribotta PD, Ausar SF, Beltramo DM, Leon AE. 2005. Interactions of hydrocolloids and sonicated-gluten
proteins. Food Hydrocoll 19:93�99.
Rojas JA, Rosell CM, de Barber CB. 1999. Pasting properties of different wheat flour�hydrocolloid systems.
Food Hydrocoll 13:27�33.
Rosell CM, Collar C, Haros M. 2007. Assessment of hydrocolloid effects on thermo-mechanical properties
of wheat using the Mixolab. Food Hydrocoll 21:452�462.
Rotsch A. 1954. Chemical and baking*Technological investigation with artificial doughs. Brot Gebeck
8:129�130.
Samuel D. 1996. Investigation of ancient Egyptian baking and brewing methods by correlative microscopy.
Science 273:488�490.
Sanchez HD, Osella CA, de la Torre MA. 2004. Use of response surface methodology to optimize gluten-
free bread fortified with soy flour and dry milk. Food Sci Technol Int 10:5�9.
Schober TJ, Messerschmidt M, Bean SR, Park S, Arendt EK. 2005. Gluten-free bread from sorghum:
quality differences among hybrids. Cereal Chem 82:394�404.
Sdepanian VL, Morais MB, Fagundes Neto F. 1999. Doenca celiaca: A evolucao dos conhecimentos desde
sua centenaria descricao original ate os dias atuais. Arq Gastroenterol 36:244�257.
Sivaramakrishnan HP, Senge B, Chattopadhyay PK. 2004. Rheological properties of rice dough for making
rice bread. J Food Eng 62:37�45.
Stevens FM, Egar-Mitchell B, Cryan E, McCarthy CF, McNicholl B. 1987. Decreasing incidence of celiac
disease. Arch Dis Child 62:465�468.
Tharanathan RN, Mahadevamma S. 2003. A review: Grain legumes a boon to human nutrition. Trends
Food Sci Technol 14:507�518.
Thompson T. 1997. Do oats belong in a gluten-free diet? J Am Diet Assoc 97:1413�1416.
Thompson T. 2000. Folate, iron and dietary fibre contents of the gluten-free diet. J Am Diet Assoc
1000:1389�1396.
Toufeili I, Dagher S, Shadarevian S, Noureddine A, Sarakbi M, Farran M. 1994. Formulation of gluten-free
pocket-type flat breads: optimization of methylcellulose, gum Arabic, and egg albumen levels by response
surface methodology. Cereal Chem 71:594�601.
This paper was first published online on iFirst on 27 November 2007.
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er L
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18/1
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