The physico-functional characteristics of starches from cowpea ( Vigna unguiculata), pigeon pea ( Cajanus cajan) and yambean ( Sphenostylis stenocarpa)

Abstract

Starches fractionated from cowpea ( Vigna unguiculata, Ife Brown), pigeon pea ( Cajanus cajan, Cita II) and yambean ( Sphenostylis stenocarpa) were comparatively studied for physical and functional properties, including granule morphology, granule sizes, water absorption capacity, water–oil absorption index, swelling capacity, ionic property, bulk density and amylographic viscosities. The three legume starch granules range in diameter size from 5–57.5 μm. The water absorption capacities of all the starches were generally low at room temperature up to 70°C. Pigeon pea starch was the least susceptible to swelling while the cowpea starch was the most susceptible. The starches displayed non-ionic character, low water activity, high bulk density, water and oil absorption capacities and type C Brabender visco-amylograms at 6.2% starch-water slurry (on dry wt basis). ©