Isolation of protein isolated from defatted Carica papaya linn. seeds: influence of pH and NaCl on its solubility and functional properties

Abstract

This work reports the isolation of protein from defatted Carica papaya Linn. Seed (CPS), with the crude protein product containing 88.08% protein. Under its natural conditions, the solubility of this protein isolate is comparable to sweet lupin protein isolate (98.79%). The solubility of the protein decreases with decreasing pH, with the minimum solubility observed at its isoelectric point (pH 4). The water holding capacity, oil holding capacity, foaming capacity, foam stability, emulsifying capacity and emulsion stability were found to be 3.65 g/g, 3.60 g/g, 26.14%, 13.06%, 74.05m2/g, 100.80%. The profiles of functional properties were determined with varying pH values and NaCl concentration, and improved properties were observed in the alkaline pH range and in the presence of NaCl.