Effect of overnight soaking and boiling on phytic acid, tannins, saponins and proximate composition in legumes

Abstract

The nutritional value of legumes depends not only on the nutrients but also on anti-nutrients that hinder
their absorption. Simple domestic cooking procedures can greatly influence nutrients and anti-nutrients in legumes.
The overnight soaking (in tap water, 0.9% w/v NaHCO3 solution and 1.5% w/v vinegar solution) prior to boiling
among three legumes was studied; red kidney beans (Phaseolus vulgaris), chickpeas (Cicer arietinum) and
bengal grams (Cicer arietinum) which significantly (p <.001) reduced phytic acid, tannins, saponins and ash
content, whereas, crude protein, crude fiber and carbohydrates increased significantly (p <.001), enhancing
the nutritional quality of legumes. The most drastic reduction of phytic acid (33.07% in red kidney beans,
41.13% in chickpeas and 40.47% in bengal grams) was observed after boiling the overnight soaked legumes in