Functional properties of protein isolates, globulin and albumin extracted from Ginkgo biloba seeds

In this study, the functional properties of Ginkgo seed protein isolate (GPI), Ginkgo seed globulin protein (GGP) and Ginkgo seed albumin protein (GAP) extracted from Ginkgo biloba seeds were investigated. The protein contents of GPI, GGP and GAP were 91.0%, 93.4% and 87.8%, respectively in the samples in which the sugar, polyphenol and crude fibre were removed by the preparation procedure. For functional properties of Ginkgo seed proteins in the natural state, GAP showed the highest oil-absorption capacity (9.3 ml/g), foaming capacity (67.8%), emulsifying capacity (65.4%) and emulsion stability (90.6%); while GPI showed the highest water absorption capacity (1.93 ml/g), and GGP showed the highest foam stability (55.5%). The differences of the chemical components, surface hydrophobicity, disulphide bond (SS) and sulfhydryl group (SH) contents of GPI, GGP and GAP, which were correlated significantly with functional properties of Ginkgo seed proteins, were also investigated. The improved functional properties, such as water absorption capacity, solubility, foaming properties and emulsifying properties of Ginkgo seed proteins were observed in a pH range of 8.0–10.0 or sodium chloride concentration of 0.5–0.75 M.