Study On The Improvement In The Emulsifying Properties Of Wheat Gluten By Proteinase

Wheat gluten is a kind of cheap and superior quality protein resources. But the presence of hydrophobic amino acids leads to poor function. Its application is limited. Emulsification is an important function of wheat gluten. So it is a very significant job that enzymatic modification of wheat gluten by controlling proteolysis can enhance the functionality.Choosing the right proteolytic enzyme, environmental condition for hydrolysis and degree of hydrolysis is crucial for enhancing emulsification of wheat gluten.Wheat gluten was hydrolyzed by Neutrase, Alcalase, Papain, Protamex.and Flavourzyme, respectively. Flavourzyme and Protamex were found to be the best proteolytic enzyme by comparing the relation between the degree of hydrolysis and emulsiability.The influence of different factors which include wheat gluten concentration, additive dosage of proteolytic enzyme, and the degree of hydrolysis were studied at the optimal temperature and pH of enzymes. On the basis of one-factor experiments, the following optimum processing condition for Flavourzyme and Protamex hydrolyzing wheat gluten were obtained using L₉(3⁴) orthogonal experimentThe optimal reaction conditions hydrolyzed by Flavourzyme were that concentration of substrate 8%, the protease usage 1000u/g, the degree of hydrolysis 7% without pretreatment. Its emulsifying ability and the emulsifying stability could reach 73.71% and 62.44% respectively. The optimal reaction conditions hydrolyzed by Protamex were that concentration of substrate 8%, the protease usage 1250u/g, the degree of hydrolysis 7% without pretreatment.Its emulsifying ability and the emulsifying stability could reach 74.5% and 63.5% respectively.Wheat gluten hydrolyzed by Flavourzyme and Protamex had much higher emulsification when the concentration of NaCl is 0.2mol/L and pH is at low or high value.The two kinds of wheat gluten hydrolyzed by Flavourzyme and Protamex were used for making butterine respectively. The conclusion indicated the emulsification of wheat gluten hydrolyzed by Protamex was better than that by Flavourzyme. But the butterine's quality of the wheat gluten hydrolyzed by Flavourzyme was better than that by Protamex, because Flavourzyme could eliminate the protein's bitterness.