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Effect of
cooking methods on available and unavailable carbohydrates
of some tropical grain legumes
David F. Apata
Unit of Nutritional Biochemistry, Department of Animal
Production, University of Ilorin, Ilorin, Nigeria. E-mail:
dfapataunilorin@yahoo.com.
Accepted 16 May, 2008 |
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The available and unavailable carbohydrate contents of
eleven tropical legumes from different seed lines were
investigated in raw, cooked and autoclaved forms. Raw
legumes contained small amounts of glucose and fructose
which ranged from 0.05 to 0.22 g/100 g and 0.24 to 0.90
g/100 g, respectively, sucrose varied between 1.49 g/100 g
and 3.76 g/100 g. Reducing sugars were higher in bambara
groundnut than other legumes. Starch was the principal
carbohydrate, ranging from 35.4 to 50.0 g/100 g. African yam
beans, lima beans and kidney beans had fairly high levels of
oligosaccharides (raffinose + stachyose) than bambara
groundnuts. Non-cellulosic polysaccharides and cellulose
contents were highest in jack bean followed by pigeon pea
TUc5537-1 and least in bambara groundnut KAB-3. Lignin was
low and fairly uniform in all the legumes. The available
carbohydrates were reduced to various extents by cooking,
whereas the unavailable carbohydrates were not affected
appreciably by heat treatment.
Key words:
Legume grains, available and unavailable carbohydrates,
cooking, autoclaving. |
