Effects of extraction solvent and isoelectric point on the quality of jack bean (Canavalia ensiformis) protein

Jack bean is a potential alternative source of protein, but studies on isolated jack bean protein (JBP) have reported a protein content of less than 90%, which cannot be classified as protein isolate. JBP isolate (JBPI) has recently been obtained using a highly alkaline solvent. This research explored mild and high alkalinity extraction solvents and determined the isoelectric point (pI) for isolating JBP. The protein loss, recovery, and nativity were analyzed. A mild alkaline solvent at pH 8.5, extraction temperature at 40 °C, and pI of pH 4.0 yielded JBPI with a protein content of 94.24% on a dry basis. A highly alkaline solvent at pH 11.0 better solubilized the protein during extraction, but the JBPI was more denatured than the JBPI obtained at pH 8.5. Thus, a mild alkaline solvent is appropriate for producing JBPI while maintaining its nativity.