Abstract:

Starches were extracted from blackeye pea (Vigna unguiculata (L.) Walp), black bean (Phaseolus vulgaris L.) and lentil (Lens culinaris M.) by wet-grinding method, and were comparatively characterized for their physico-chemical properties with sweet potato and corn starches as the controls. Most of legume starch granules were kidney-shaped, while others were spherical. Obvious birefringence was also observed. The contents of apparent amylose in blackeye pea, black bean and lentil starches were 34.98%, 45.35% and 37.24%, respectively. The swelling capability and solubility of legume starch displayed an increase at a higher temperature. The three legume starches displayed a pasting temperature ranging from 72.9 to 77.0 ℃. Black bean starch exhibited the highest pasting temperature as well as the lowest peak viscosity, breakdown value, final viscosity and retrogradation value. The pasting property of blackeye pea starch was opposite to that of black bean starch. The To , Tp and Tc of the three legume starches revealed a significant difference. However, no significant difference was observed in their enthalpy. The order of starch enthalpy from strong to weak was lentil starch, blackeye pea starch and black bean starch.

Key words: blackeye pea, black bean, entil, starch, physico-chemical property