Effect of Tea Polyphenols on the Structural Property of Gluten in Wheat Dough

The effect of tea polyphenols on the structural property of gluten in the wheat dough was analyzed by Raman spectroscopy and scanning electron microscopy(SEM). With 0.5%,1.0%,2.0% of tea polyphenols addition,the content of wet gluten in the dough decreased by 17.8%,66.3% and 93.3%,the free amino content increased by 57%,151% and 313%,and the content of sulfhydryl increased by 48%,69% and 111%,respectively. Raman spectroscopy analysis showed that the addition of tea polyphenols led to an increasing in hydrogen bonding of dough,the relative content of α-helix(21.9%) reduced,and the β-sheet and random coil secondary structure increased by 17.2% and 5.1%,and dose-dependently reduced the relative absorption intensity of tryptophan residue at 757 cm^-1. Additionally,the analysis of the conformation of disulfide bonds showed that they were transformed from gauche-gauche-gauche to gauche-gauche-trans with an increase rate of 3.0%,6.0%,13.4% along the content of tea polyphenols addition of 0.5%,1.0% to 2.0%. SEM and CSLM analysis revealed a disrupted gluten network structure. Thus,preventing the interaction of tea polyphenols with gluten is essential for the development of the functional dough-based food containing flavonoids.