EFFECTS OF SOAKING AND COOKING ON PHYSICAL CHARACTERISTICS, TANNIN CONTENTS AND PROTEIN DIGESTIBILITY OF KIDNEY BEANS (PHASEOLUS VULGARIS L.)
Keywords:
Kidney beans, Soaking, Cooking, Tannin, In vitro protein digestibility.Abstract
This study reports the effects of soaking and cooking methodson some physical characteristics, tannin contents
and in vitro proteindigestibility of kidneybeans. Soakingofkidney beans insodium bicarbonate solutiongave rise to
lower hydration capacity, hydrationindex, swellingcapacityandcookingtime than soaking insimple wateror neutral
sodiumchloride solution.Tannin contentsofredkidneybeanswerereducedby soaking at30° and 100°Cfordifferent
periods. However, soaking in sodium bicarbonate solution with or without sodium chloride was more efficient in
reducing tannin contents. Maximum improvement in proteindigestibility was also observed by soaking kidney beans
in mild alkaline solutions. Tannin contents were further reduced alongwith improvement in protein digestibility as a
result of cooking.
