Abstract:Objective: to study the effects of different heating temperatures and times on the structural characteristics, enzymatic hydrolysis characteristic, and the content of glutamine at non-nitrogen terminal of wheat gluten. Methods: Firstly, wheat gluten were pretreated with heating treatment at three heating temperatures (60, 70, 80, 90 ℃) for (15, 30, 60 min) and then enzymatically hydrolyzed by Alcalase 2.4L alkaline protease. Using the untreated wheat gluten hydrolysate as a reference, we compared the structure changes of wheat gluten and the hydrolysis efficiency and content of glutamine at non-nitrogen terminal of hydrolysates. Results: the dough structure formed by wheat gluten proteins in water gradually loosened or even dispersed with heating treatment at increasing heating temperature, and at the same time heat treatment changed the secondary structure of wheat gluten, which might expose more enzymatic cleavage sites. Moreover, heat treatment significantly increased the extent of hydrolysis and increased the content of glutamine at non-nitrogen terminal (P<0.05). In particular, compared to wheat gluten without heating treatment, the control protease lysates wheat gluten with heating treatment at 90 ℃ for 30 min showed better performance, the content of the components with a molecular weight less than 1 ku of whose hydrolysates increased from 75.85% to 80.75% and the content of glutamine at non-nitrogen terminal of whose hydrolysates increased from 26.27% to 34.87%. Conclusions: heat treatment was beneficial in hydrolysis and increasing the content of glutamine at non-nitrogen terminal of wheat gluten hydrolysates.