Studies On Plastein Synthesis By Corn Protein And Soy Protein

The plastein reaction is considered to involve the formation of polypeptides by a reversal of the usual peptide bond hydrolysis to produce "resynthesized" protein or polypeptides from a hydrolysate of protein. It can improve biological value and functional properties of food proteins because of its process to meet demands of modern food industry.Corn protein is by-production of maize processing, which is used in crude feedstuff or discharged directly as wastes, it is a great mass of waste and pollution for environment. The sixty percent of corn protein is protein, so the reclaim protein form corn protein is important to develop food industry and protein industry. The contents of amino acid are higher than normal proteins in corn protein except for methionine. Soy protein is a kind of excellent protein, but the contents of methionine is low. So synthesis plastein by corn protein and soy protein can recycle corn ptorein and improve the functional properties of corn protein and soy protein.A method of immobilize Alcalase and papain proteinase by Fe₃O₄ magnetic chitosan was studied. The results showed: the conditions of immobilize Alcalase is: concentration of chitosan, 2%; concentration of glutaraldehyde, 20%; pH, 8.0; quantity of Alcalase, 1mL; time of deposit, 8h. the recycling rate of proteinase is 25.5%. the conditions of immobilize papain is: concentration of chitosan, 2%; concentration of glutaraldehyde, 20%; pH, 6.5; quantity of papain, 100mg; time of deposit, 8h. the recycling rate of proteinase is 44.8%.Com protein hydrolyzed by Alcalase proteinase was studied. The regnession Revolving Orthogonal and Tropical Design was adopted to study the effects offactors on degrees of hydrolysis (DH) and a mathmatics modle was built .F-test t-test and application test were used to verify the modle. The results indicated the testing goodness of fit .The contribution of three factors to DH was temperature >[E]/[S]>pH-value. The optimum of condition was battened, T, 60℃; [E]/[S], 4.5%; pH ,8.0, and DH is 30.18%, which is content for plastein reaction.Plastein synthesis with com protein hydrolysates and soy protein hydrolysates by papain proteinase was studied. The regnession Revolving Orthogonal and Tropical Design was adopted to study the effects offactors on plastein productivity and a mathmatics modle was built .F-test t-test and application test were used to verify the modle. The results indicated the testing goodness of fit .The contribution of three factors to plastein productivity was [E]/ [S]>pH> concentration of substrate. The optimum of condition was battened, pH, 5.6; [E]/[S], 2%; concentration ratio of substrate ,1/3 and plastein productivity is 90%.