Effect of steam cooking and storage on formation of resistant starch from debranched Cassava (Manihot esculenta) Starch
1Abioye, V.F., 1Adeyemi, I.A., 1Akinwande, B.A., 2Kulakow, P. and 2Maziya-Dixon, B. 1LAUTECH, Ogbomoso, Nigeria. 2IITA, Nigeria
World Congress on Root and Tuber Crops Nanning, Guangxi, China, January 18-‐22, 2016
Resistant starch v Total amount of starch undigested in the
small intestine v Passes into the colon where it can be
fermented by natural microflora to short-chain fatty acids
v These metabolites appear to have important
biological effects for improved physical and mental health (Birt et al., 2013).
Benefits of resistant starch
v Pre-biotic effect on colon micro flora v Improves cholesterol metabolism v Reduce the risk of colon cancer v Reduce glycemic index (GI) value with
beneficial implications for obesity. Type II diabetes
v Prevention of gall stone formation, v Cardiovascular diseases and also increase
absorption of minerals
Types of RS v Physically inaccessible
starch (RS1)
v Starch granules (RS2)
v Retrograded starch (RS3)
v Chemically modified starches (RS4)
Production of RS3 v RS3 is produced by gelatinization and
retrogradation v The type of starch, processing condition,
and duration and storage conditions. v Processing techniques includes baking,
pasta production, extrusion cooking, steam cooking, autoclaving (Sajilata et al., 2006).
v Commercially, RS3 have been prepared from high amylose corn starch (>40% amylose).
v Native cassava starch contains
amylose (19.6% to 24.1%). v Cassava is suitable for RS3 production
(Worawikunya, 2007)
v Nigeria is the world's largest producer of cassava (about 54 million metric tons per annum)
v Steam cooking of legumes has been
reported to increase the RS from 19% to 31% (Tovar and Melito, 1996).
Objective v To explore the availability of improved
varieties of cassava in Nigeria. v By studying the effects of steam cooking
and subsequent storage condition on the formation of resistant
v To enhance the use of cassava starch as a
functional food and thus increase the industrial utilization of cassava in Nigeria.
Materials
v TMS 30572 and 98/0581 (obtained from IITA Ibadan)
v Commercial isoamylase (Pseudomonas sp.)
v Amyloglucosidase (EC. 3.2.1.3 from Aspergillus niger, 11,500 U/mL)
v Pancreatic-α-amylase (Sigma-Aldrich, Steinheim, Germany)
v All the chemicals used were of analytical grade
Method v Starch was extracted from these two
varieties of cassava (IITA, 2005). v Enzymatic debranching of cassava
starch (Mutungi et al.,2009) v The debranched and undebranched
starch samples were steam cooked at both at atmospheric pressure and high pressure (Alejandra et al.,1998).
Analysis v Proximate composition (AOAC,2005). v Amylose (Williams et al., 1970). v The total starch contents (Dubois et al.,
1956; Mcready 1970). v Resistant starch content (McCleary et al.,
2002).
Table 1: Chemical composition of the two varieties of cassava starch
ComposiBon TMS 30572 TMS 98/0581
Starch 89.23±0.15 88.9±0.17
Amylose 22.5±0.50 21.0±0.29
AmylopecBn 77.5 79
Moisture Content 12.30±0.01 11.44±0.01
Protein 0.17±0.06 0.13±0.12
Fat 0.37±0.06 0.37±0.15
Fibre 0.23±0.12 0.20±0.01
Ash 0.36±0.02 0.37±0.02
Table 2: Resistant starch contents (g/100g) of the two varieties of cassava starch obtained by steam cooking
Variety Atmospheric pressure High pressure
Undebranched Debranched Undebranched Debranched
30572 6.01 19.55 5.68 18.75
98/0581 5.99 19.25 5.58 18.25
Fig 1: Effect of storage condition and time on formation of resistant starch from undebranched and debranched cassava starch (TMS 30572) steam cooked at atmospheric pressure
5.9
6
6.1
6.2
0hrs 24hrs 48hrs
RS(g/10
0g)
Storage Time
Freezing
RefrigeraDon 18.5
19 19.5 20
20.5 21
21.5
0hrs 24hrs 48hrs
RS(g/10
0g)
Storage Time
Fig 2: Effect of storage condition and time on formation of resistant starch from undebranched and debranched cassava starch (TMS 98/0581)steam cooked at atmospheric pressure
5.8
5.9
6
6.1
6.2
6.3
0hrs 24hrs 48hrs
RS(
( g/100
g)
Storage Bme
Freezing
RefrigeraDon
18
18.5
19
19.5
20
20.5
21
21.5
0hrs 24hrs 48hrs
RS(g/10
0g)
Storage Bme
Freezing
RefrigeraDon
5.4
5.6
5.8
6
6.2
0hrs 24hrs 48hrs
RS(g/10
0g)
Storage Time
Freezing
RefrigeraDon
17.5 18
18.5 19
19.5 20
20.5 21
0hrs 24hrs 48hrs
RS(g/10
0g)
Storage Bme
Freezing
RefrigeraDon
Fig 3: Effect of storage condition and time on formation of resistant starch from undebranched and debranched cassava starch (TMS 30572) steam cooked at high pressure
5.4
5.6
5.8
6
6.2
0hrs 24hrs 48hrs
RS(g/10
0g)
Storage Time
Freezing
RefrigeraDon
17.5 18
18.5 19
19.5 20
20.5 21
0hrs 24hrs
48hrs
RS(g/10
0g)
Storage Bme
Freezing
RefrigeraDon
Fig 4: Effect of storage condition and time on formation of resistant starch from undebranched and debranched cassava starch (TMS 98/0581) steam cooked at high pressure
Conclusion v Steam cooking as a processing method
have potentials to increase the RS contents of cassava
v cassava roots could serve as functional food through conversion to RS3
Probable Uses v Bread and other baked goods v Pasta, cereal and batters v Textural properties in imitation cheese v Food supplement v binder in foods