The Influences Of Succinylation And Protease Modification On Wheat Gluten Protein Functionality

Wheat gluten protein (WGP) is a kind of widely used food additive. The water-insolubility of gluten is one of the major limitations for its more extensive use in food processing. WGP functionalities could be improved by chemical modification, enzymatical hydrolyzation or multiple modification.The influence of different factors which include WGP concentration, succinic anhydride dosage, reaction temperature, pH and reaction time to functionalities of product were studied. The influences of succinylation and protease modification on wheat gluten protein functionalities were studied. The influences of different degrees of hydrolysis (DH) on the functionalities of products which included solubility, foaming capacity (FC) and foaming stability (FS) were studied. Multiple modification technological conditions were examined and the functionalities of multiple modified WGP were specially analyzed compared to original WGP, succinyled WGP, neutral protease wheat gluten hydrolysates (WGH) and alcalase WGH. The influences of multiple modified WGP which was used as additive on the stickness of dough and on the quality of bread was preliminary examined.When WGP concentration was 12%, succinic anhydride dosage was 8%, reaction temperature was 45℃, pH was 8.0 and reaction time was 30min, The properties of modified WGP were much improved. The result showed that when pH range over 3-11 and DH from 4% to 12%, the solubility of single protease WGHs increased with the DH while the foaming properties were impaired.The foaming capacity of neutral protease WGH decreased from 135% with DH 4% to 45% with DH 12%, while foaming stability decreased from 25% to 10%. The foaming capacity of alkaline protease WGH decreased from 70% to 10%. while foaming stability decreased from 25% to 7.5%. The solubility of modified WGP increased with the DH increased too, the values were all above 80%, higher than original WGP, succinyled WGP and protease WGHs. The foaming properties increased at first and then decreased and lower than single condition modified WGP. In addition, multiple modified WGP could improve the stickiness of dough and the properties of bread.