Functional properties of selected legumes flour as influenced by pH

Abstract

showed that the protein solubility and emulsifying and foaming properties at different pH levels of the selected legumes flour were varied. The minimum values of protein solubility, emulsifying capacity, emulsion stability and foaming capacity were found at pH 4.0. On either sides of this pH such properties were significantly increased. The solubility of the legumes flours was observed to be high at pH 8. The emulsifying activity (EA) improved above and below pH 4.0 and was higher in alkaline than acidic pH with a maximum value at pH 8.0. The highest emulsion stability (ES) of the flour was found at pH 6.0. At alkaline pH (8.0-12.0) the ES of the legumes flour was significantly decreased. The maximum foaming capacity (FC) for phaseolus (84%), pigeon pea (70%), cowpea (94%), and hyacinth bean (90%) flours was found at pH 12.0. The foam stability (FS) of the selected legumes flour at a given pH value was significantly (p≤0.05) decreased with time. The FS at pH 8.0 was low compared to pH 10 and 12.0. Generally, high FS was observed at acidic pH compared to alkaline pH region.