Chemical investigation of Erythrina variegata Linn. seed proteins

Proteins were extracted from deoiled seeds of Erythrina variegata Linn., a potential source of non-conventional seed, in aqueous solutions of various pHs or by different concentrations of NaCl, KCl, CaCl2 and MgSO4 at pH 7.0. Nitrogen contents of the seeds and deoiled seeds showed good protein content. Fractionation of protein was done to separate albumin, globulin, prolamine and glutelin. Amino acid analysis of the total protein isolates (TPI) and the fractions isolated (except prolamine) identified 17 amino acids, most of which were essential. The molecular weights of TPI and the fractions were determined by SDS–PAGE electrophoresis. The results showed that TPI was composed of twelve bands, eight for globulin, nine for prolamine and six for glutelin. Studies on surface structure of the proteins and seed flour by scanning electron microscopy (SEM) are also included.