Chemical and Functional Properties of Protein Isolate from Cowpea (Vigna Unguiculata)

Abstract

Cowpea (Vigna unguiculata) is potentially used as food ingredient since it has high protein content around 25%. This study was focused on the observation of the chemical and functional properties of cowpea protein isolate (CPI) compared to the chemical and functional properties of soy protein isolate (SPI) commercial with three repetitions in each parameter, then the data were analyzed descriptively. The results showed that CPI has the chemical properties of the moisture content, ash content, and carbohydrate content, which value is smaller than the value of SPI respectively 7.97%, 1.75%, 1.21%. CPI has protein and fat content which is higher, compared to SPI with consecutive values 88.06% and 1.05%. CPI contains more 7S globulin fraction compared with 11S and inversely related to SPI. CPI has functional properties including maximum solubility at pH 8, smaller foam capacity and higher foam stability than the value of SPI successive 68 ml/g and 8%, lower OHC and WHC than SPI at successive 84.89% and 136.61%, lower emulsion capacity and higher emulsion stability than the value of SPI with consecutive 2.41 m /g and 78.15 hours, lower than the gelation of SPI with a value of 4 gf. CPI has a major fraction of protein bands with molecular weight of 59.11 kDa and 54.22 kDa, while the fraction of SPI has major protein bands with molecular weight of 50.66 kDa and 57.02 kDa