ISSN: 2574-2701
Authors: Adeyoju OA, Chibudike HO*, Oluwole BO, Olu-Owolabi BI and hibudike CE
Effect of pH on the foaming properties (FC and FS) of protein isolates from two Varieties (DAS & BS) of Nigerian cultivated Solojo cowpea (Vigna Unguiculata L. Walp) was investigated. Results show that the foaming capacity (FC) followed the solubility trend, with a high foaming capacity at pH 2, which slowly reduced between pH 4 - 6 and gradual increase again with pH as the pH approached 10, where it had another high value. As shown in Figures 1-6 noticeable changes in FC were detected as the pH of the protein solution progressed from pH 2 to 10, with minimum foaming capacity at pH 4 in all cases except for DFDAS flour and BS protein isolate (pH 6). The foaming capacity value for 6 h soaked and 48 hr germinated flours, at pH 4 were observed to be greater than at pH 2 and 6. While the maximum was observed in some cases at pH 8 and some pH 10 but FFDAS Raw, 36 and 48 hr; FFBS, 6 hr; DFBS, Raw and 72 hr; BS, 6 and 24 hr germinated, all had their own max values at pH 2. Defatting was also observed to improve the foaming capacity values of all the treatment. The foaming capacity ranged between 15.19 to 121.16%; 44.76 to 127.36%; 31.23 to 110.93%; 30.84 to 121.16%; 64.97 to 210.00%; 62.67 to 222.00% for FFDAS, DFDAS, FFBS, DFBS, DAS, and BS, respectively. The pattern of FC change followed the pH dependent solubility flow of the test material, showing the importance of solubility on foam formation which confirms that solubility of protein has a great influence on the activities of foam also increasing the pH from 4 to 10 improved the foaming characteristics of flour. This observation proved the authenticity that foaming property depends on protein solubility. The foaming capacity of cowpea protein isolates was pH dependent and high at alkaline pH in comparison to acid region.
Keywords: Solojo Cowpea; Under-utilized legumes; Essential Amino Acids; Nutraceuticals; BS; DA; Gelation Property LGC
