Effects of Packaging Methods and Wheat Varieties on Starch Aging in Wine-brewed Steamed Bread during Storage

In order to explore the relationship between the internal starch aging of wine-stuffed steamed bread stored at 4 ℃ for 7 days and the packaging form as well as wheat varieties, ‘Zhengmai 113’, ‘Yangmai 20’ and ‘Xinmai 129’ were used as raw materials to make wine-stuffed steamed bread and then treated with unpackaged and sealed packaging. The changes in moisture, texture characteristics, starch order, microstructure, and sensory quality during the storage period were analyzed. The internal starch aging trend was evaluated by the Avrami equation. The results showed that, compared with the same group of wheat, the amylose content of ‘Zhengmai 113’ and the amylopectin content of ‘Xinmai 129’ were significantly different (P<0.05), and the crude protein content of ‘Yangmai 20’ was not significantly different. During the storage period, the hardness of unpackaged ‘Zhengmai 113’ and sealed packaged ‘Yangmai 20’ samples increased, the elasticity of unpackaged ‘Yangmai 20’ samples increased, while the hardness of sealed packaged ‘Xinmai 129’ samples showed no significant change. The infrared spectra indicated that the internal starch of the unpackaged ‘Zhengmai 113’ and the sealed packaged ‘Yangmai 20’ samples with a higher ratio of (1047/1025) cm⁻¹ showed an ordered transformation. Sensory and microscopic structures indicated that all three groups of unpackaged samples cracked and gelatinized starch particles could be seen at the fracture sites. The appearance of the three groups of sealed packaged samples was intact, but the internal pores were blurred. The construction of the Avrami dynamic equation based on the hardness index indicated that the starch aging and crystallization rates in the unpackaged ‘Zhengmai 113’ and sealed packaged ‘Yangmai 20’ samples were relatively high. In conclusion, the use of ‘Xinmai 129’ and sealed packaging treatment can effectively delay the aging of starch inside the 4 ℃ stored wine-stuffed steamed buns and effectively improve their storage and transportation quality.