Functional characteristics of cowpea (Vigna unguiculata) flour and starch as affected by soaking, boiling, and fungal fermentation before milling

Functional characteristics of cowpea flour and starch as affected by soaking, soaking and boiling (S/B), and fermentation of seeds with Rhizopus microsporus var. oligosporus before milling were investigated. Soaking and fungal fermentation had fewer effects on flour and starch functionality compared to boiling. Boiling drastically reduced foamability and thus increased specific gravity of whipped cowpea paste. The gradual increase in total color differences of pastes prepared from S/B seeds with or without fermentation was due to a gradual decrease in lightness (L∗). The more intense yellow color observed in whipped pastes from S/B seeds after fermentation was due to increased b∗ and decreased L∗ values. Starch from all treatments had greater swelling volume than flour. Significant reductions in swelling volume of flour and starch were due to the boiling treatment. Pasting characteristics of control flour and starch are concentration dependent. The pasting curve pattern of cowpea flour differed markedly from that of cowpea starch.