QUANTIFYING THE EFFECTS OF POSTHARVEST STORAGE AND SOAKING PRETREATMENTS ON THE COOKING QUALITY OF COMMON BEANS (PHASEOLUS VULGARIS)

Abstract

Cooking quality of common beans greatly influences acceptability. The objective of this study was to quantify the effect of bean type, storage time, temperature and relative humidity (RH) on the cooking time of four bean types grown in Kenya. Beans were stored under different temperature (25, 35 and 45C) and RH (75 and 83%). After sampling, they were pre-soaked or not and cooked to generate cooking curves which were subjected to nonlinear regression. Significance of the different variables was evaluated using mixed model regression. Higher storage temperatures (35 and 45C), higher RH (83%) and extended time significantly increased lag phase and cooking time. Soaking pretreatments reduced cooking time. Canadian wonder and Pinto beans took long thus hard-to-cook while Rose coco and Red haricot took short cooking time, thus, easy-to-cook. This work demonstrated the critical nature of bean type, storage and pretreatment conditions in influencing bean cooking quality.