Fractionation and Some Chemical Studies on Ailanthus excelsa Roxb. Seed Protein

摘要

The unavailability of protein foods, particularly in the context of population growth, has been an important factor in the protein malnutrition encountered in developing countries. The fractionation, gel filtration and polyacrylamide gel electrophoresis (PAGE) of Ailanthus excelsa seed (a nontraditional source containing 15.81% protein) proteins were carried out in the present study, and their solubility profiles, surface topographies and amino acid compositions were evaluated. The globulin fraction dominated the seed protein composition, accounting for 51.31% (w/w) of the total soluble proteins in the seeds. Protein isolate and protein fractions of A. excelsa seeds showed similar topographical structures to those of other plant seed proteins. Analysis of the isolated proteins identified 17 amino acids, of which nine were essential. Gel filtration on Sephadex G-200 revealed the presence of seven components. PAGE detected different polypeptide bands in the range of 28.8-154.9 kDa in the protein isolate as well as in protein fractions for A. excelsa. The amino acid compositions, the solubility patterns and the high abundances of low molecular weight proteins indicate that the isolated seed protein of A. excelsa may be a potential food protein.