White salt dried noodles (dried noodles) account for about 10%of China’s flour products. Drying can reduce the moisture content of dried noodles to less than 14%, greatly improve the stability of physical and chemical properties of dried noodles and extend the shelf life. It is one of the important processes in the manufacturing process of dried noodles. The essence of dried noodles is that water migrates from wheat protein/starch system to the outside world, the state of water in the system changes from”bound water + free water” to bound water, the water activity decreases, and the system gradually changes from rubber state to glass state; That is, drying of dried noodles is a process in which water in the wheat protein/starch system migrates to the outside world and changes towards vitrification. During this process, the deformation modulus of wheat protein/starch system will also change. Too fast glass transition rate, or the resulting uneven distribution of deformation modulus, will increase the internal stress. In order to balance the internal stress, the wheat protein/starch system will be deformed, and even the structure will be destroyed, resulting in the distortion, cracking and splitting of vermicelli. In response to the above problems, the grain processing and quality control innovation team used relative humidity to control the water migration rate, so as to control the glass transition rate of wheat protein/starch system, and used image processing methods to quantitatively characterize the deformation degree of the system. The results showed that the water activity of dried noodles and the relative humidity of the environment controlled the water migration rate of dried noodles, and there was a positive correlation between them; Higher water migration rate causes greater deformation. Relevant research results have been authorized with one invention patent, and LWT – Food Science and technology has been published online. The research was supported by modern agricultural industrial technology system (cars-03), National Natural Science Foundation of China (32172245 and 31771927), innovation project of Chinese Academy of Agricultural Sciences and other projects.
1. Yanfei Gong, Ang Meng, Yingquan Zhang, Bo Zhang, Danyang Ying, Boli Guo, Yimin Wei. Effect of water migration rate on the deformation characteristics of wheat starch/gluten extruded noodles. LWT, 163, 2022, 113546, https://doi.org/10.1016/j.lwt.2022.113546.
2. Invention patent, food drying method, zl202110345637.4, authorized on June 22, 2002.