Bene W. Abbey

Effect of processing on flatus producing oligosaccharides in cowpea (Vigna unguiculata) and the tropical African yam bean (Sphenostylis stenocarpa)

The effect of dehulling, soaking and soaking/cooking on sucrose, raffinose and stachyose in mature dry seeds of nine varieties of cowpea (Vigna unguiculata) and one variety of tropical African yam bean (Sphenostylis stenocarpa) were investigated. The results showed a progressive decrease in sucrose, raffinose, and stachyose contents. Soaking for 12 hours and cooking for 30 min eliminated most of the sucrose, raffinose and stachyose. The sugar contents in whole raw cowpea were sucrose 0.73–4.58%, raffinose 0.71–6.86% and stachyose 2.38–3.87%, and for tropical African yam bean sucrose 4.08%, raffinose 1.08% and stachyose 4.14% while the seeds soaked for 12 hours and cooked for 30 min had for cowpea sucrose 0.03–0.81%, raffinose 0.04–0.20% and stachyose 0.12–0.72%, and tropical African yam bean sucrose 0.70%, raffinose 0.40% and stachyose 0.41%.

Composition and flatulence-producing potential of commonly eaten Nigerian and American legumes

Sixteen samples of dry, mature legume seeds representing eight species purchased in markets either in Port Harcourt, Nigeria, or Griffin, GA, were cooked in boiling water until tender and freeze-dried along with cookwater. Flatulence potential measured as ml H2 produced per gram of legume solids consumed was measured with rats housed in glass life-support chambers designed to collect hydrogen while supplying oxygen and absorbing water and carbon dioxide. Hydrogen was quantified by GLC using a molecular sieve column. Mono-, di- and oligosaccharides were determined by HPLC. Starch content was measured as glucose in a YSI analyzer and digestibility was determined in vitro with pancreatic amylase. Hydrogen production was positively correlated with contents of xylose and fructose as well as stachyose and an unknown thought to be verbascose, not correlated with raffinose, and negatively correlated with galactose and indigestible starch.

Kinetics of heat-inactivation of trypsin inhibitors from the African yam bean (Sphenostylis stenocarpa)

Abstract Six different solvents were investigated for their efficiency in the extraction of trypsin inhibitors from the African yam bean. Of these, sodium hydroxide extract gave a marginally higher specific trypsin inhibitory activity (4·32 × 10−2) than those of sodium chloride (4·10 × 10−2) and distilled water (3·93 × 10−2). The Km and Vmax for trypsin in the presence of a certain amount of trypsin inhibitor activity decreased as process temperature increased. At a fixed trypsin concentration of 100 μg ml−1, the rate of inactivation of trypsin inhibitor activity increased as substrate concentration increased from 0·230 m m to 0·575 m m . The rate, however, decreased as substrate concentration was further increased from 0·690 m m to 1·150 m m due to substrate inhibition. At a constant period of heating (30 min), trypsin inhibitor activity (TIA) decreased from 2·21 to 0·332 mg pure trypsin inhibited per gram of sample as temperature of heat treatment increased from 80–180°C, and the determined values of the first order inactivation rate constants increased. As the assay pH decreased from 10·5 to 5·50, the inactivation energy decreased from 21 155-10 496 J mol−1. At a constant temperature of heat treatment, trypsin inhibitor activity decreased over time.