Alleviative Effects of Glutenin Macropolymer on the Quality Deterioration of Steamed Stuffed Bun During Freeze-Thaw Cycles

Glutenin macropolymer (GMP) plays a crucial role in counteracting the effects of freezing and ultimately improving the quality of steam bread. However, due to the different composition, structure, shape, and processing technology of steamed stuffed bun, the effects of GMP on steamed stuffed bun are totally unclear. In this study, we mainly concentrated on investigating the improvement effects of GMP on steamed stuffed bun after freeze-thaw cycles, which was compared with the addition of wheat gluten (WG). Results revealed that compared with the control group and WG group, after three freeze-thaw times, steamed stuffed bun with added GMP had a larger specific volume (3.95 cm3/g), springiness (0.885), brightness (80.57), more uniform cell structure, and more acceptable appearance. The addition of GMP significantly reduced the levels of free thiol groups and the moisture migration in frozen dough, suggesting an enhanced freeze-thaw resistance of GMP dough. Dynamic rheology indicated that GMP improved the rheological properties of dough primarily by enhancing its elasticity. Moreover, the incorporation of GMP exhibited better low-temperature protection than that of WG. The confocal laser scanning microscope (CLSM) images and protein network analysis (PNA) further illustrated that addition of GMP led to a more intact and continuous gluten network. Talking all together, our findings demonstrated that GMP could be used as a potential improver in steamed stuffed bun or other dough products.