Effect of Concentration (EC) on Emulsifying Activity (EA) of Protein Isolates from Two Varieties (DAS and BS) of Nigerian Cultivated Solojo Cowpea (Vigna Unguiculata L. Walp)

Emulsifying Activity (EA) of raw (native/ control) and germinated Dark-ash Solojo Cowpea (FFDAS, DFDAS, FFBS and DFBS flours; DAS and BS protein isolate) were all concentration dependent. The 6h DFDAS flour and raw DAS isolate both had the emulsifying activity increasing up to 2% w/v before initial fall of activity with increase in concentration. FFDAS Raw, 24 h, 48 h and 72 h; DFDAS 24 h, 48 h, 72 h; FFBS 6 h, 24 h, 48 h, 72 h; DFBS 6 h; 24 h; DAS 48 h; BS 36 h, 48 h and 72 h, all had their EA increasing with rise in concentration up to 4%w/v; while FFDAS 36 h; DFDAS Raw, 36 h; FFBS Raw, 36 h; DFBS 36 h, 48 h, 72 h; DAS 6 h, 36 h; BS Raw, 6 h and 24 h germinated flour and protein isolates went up to 6% w/v before additional rise in concentration brought about a decrease in value. Only DAS 24 h germinated protein isolate gave a rise of up to 8% w/v before decline in emulsifying activity took place. The values of the emulsifying activity ranged between 42.45±2.54 and 49.30±0.96%; 43.48±4.35 and 47.68±0.37%; 43.75±0.55 and 60.57±2.10%; 44.37±1.57 and 47.74±0.36%; 41.36±3.66 and 78.26±4.35%; 42.22±2.41 and 67.26±1.96%, for FFDAS, DFDAS, FFBS, DFBS, DAS and BS respectively. Germination was observed to improve EA of the Solojo flours and isolates. Varietal difference was also observed in the effect of germination on EA, FFBS was found to have a higher EA than FFDAS. The isolate had the DAS having a better EA than the BS. This could be due to the degree of uncoiling of the protein molecule and also the quantity of hydrophilic and non-polar constituent on the interface of the molecule.

Effect of Concentration (EC) on Emulsifying Activity (EA) of Protein Isolates from Two Varieties (DAS and BS) of Nigerian Cultivated Solojo Cowpea (Vigna Unguiculata L. Walp)

Olubamike A. Adeyoju, Effect of Concentration (EC) on Emulsifying Activity (EA) of Protein Isolates from Two Varieties (DAS and BS) of Nigerian Cultivated Solojo Cowpea (Vigna Unguiculata L. Walp)