Some antinutritional factors in rice bean ( Vigna umbellata): Effects of domestic processing and cooking methods

Abstract

The present investigation was conducted to study the concentration of polyphenols, phytic acid and saponins of five high-yielding varieties of rice bean ( Vigna umbellata) and one variety each of green gram and black gram as affected by various domestic processing and cooking methods which included soaking in tap water for 6, 12 and 18 h; sprouting for 40 and 60 h; ordinary cooking of unsoaked and soaked seeds; and autoclaving of unsoaked and soaked seeds. There was a successive and significant reduction in the contents of antinutritional factors with increase in soaking and sprouting period. A markedly greater reduction in these factors was observed when soaked seeds were cooked and autoclaved than when unsoaked seeds were cooked and autoclaved. Among the various domestic processing and cooking methods, maximum reduction of antinutritional factors was observed when soaked seeds were autoclaved.