INFLUENCE OF SOAKING AND HYDROTHERMAL TECHNIQUES ON ANTINUTRITIONAL COMPONENTS AND IN VITRO MULTIENZYMES PROTEIN DIGESTIBILITY OF VIGNA RACEMOSA - AN UNDERUTILISED HARD-TO-COOK LEGUME.

This study is aimed at determining the effects of simple and cheap hydrothermal techniques on the antinutrtional components and in vitro multienzymes protein digestibility of Vigna racemosa, an underutilised hard-to-cook legume. Seeds of V. racemosa were subjected to aqueous soaking and four hydrothermal processing methods - atmospheric boiling and steaming; pressure boiling and steaming. The effects of soaking and the hydrothermal techniques on the antinutrtional components (phytic acid, saponin, tannin and trypsin inhibitor activity) and the in vitro protein digestibility were investigated. Increase in hydration level caused more seepage of the antinutrients into the soaking water. With the exception of trypsin inhibitor activity that was totally eliminated, other antinutritonal components experienced significant reduction (p<0.05) when the seeds were subjected to the various hydrothermal processing techniques. The raw sample has protein digestibility of 40.11% while steaming at atmospheric pressure and steaming at elevated pressure caused percentage digestibility of 87.11% and 87.36%, respectively. The boiling treatments resulted in better percentage protein digestibility of 87.91%. Application of these simple and cost effective hydrothermal processing methods resulted in significant decrease in the antinutrtional components and hence improvement of protein digestibility. Increase in utilisation of this legume for foods could strengthen dietary diversity and healthy eating habit and thus alleviate the problems of protein energy malnutrition and food insecurity. [ABSTRACT FROM AUTHOR]