Gelation, thermal and pasting properties of pigeon pea (Cajanus cajan L.), dolichos bean (Dolichos lablab L.) and jack bean (Canavalia ensiformis) flours

Abstract

This study evaluated the rheological, thermal and pasting properties of pigeon pea (PP), dolichos bean (DB) and jack bean (JB) legume flours and gels. Starch and protein contents were also measured and its molecular weight distribution was determined by electrophoresis. PP and DB showed the highest viscosities while JB had the highest pasting temperature. The minimum flour concentrations for gel formation were estimated at 6-8% for DB and PP and 10% for JB. Above these concentrations all flour suspensions heated to 95 C led to gels with a solid-like behavior. Differential scanning calorimetry showed two endothermic peaks in all flours at 80-89 C and 96-100 C. Avrami model was successfully fitted to the hardening kinetics of PP and DB gels stored at 4 C. The half-life times were 22 and 6 h for PP and DB respectively. PP and DB flours were able to form self-supporting gels and could be applied in the formulation of gel-like foods.