Enzymatic preparation of immunomodulatory hydrolysates from defatted wheat germ ( Triticum Vulgare ) globulin

Summary Defatted wheat germ globulin ( DWGG ) was hydrolysed using the enzymes alcalase, neutrase, papain, pepsin or trypsin to improve the immunomodulatory effects of the protein. The degree of hydrolysis ( DH ), molecular weight distribution, hydrophobicity, secondary structures and immunomodulatory activities were determined. The DH of hydrolysate using alcalase or neutrase was higher ( P < 0.05) than that of hydrolysate prepared by other proteases. Alcalase hydrolysate ( AH ) had the strongest ( P < 0.05) immunomodulatory activity with respect to lymphocyte proliferation, phagocytosis of neutral red and secretion of pro‐inflammatory cytokines. The molecular weight of AH ranged between 300 and 1450 Da and was composed of α‐helix and β‐turns. AH also showed the highest hydrophobic value ( P < 0.05). The DH and hydrophobicity appear to be related to immunomodulatory activities. The hydrolysate prepared by the alcalase treatment on DWGG may be used as an immune supplement by the food industry.