Genomics and Applied Biology 2026, Vol.17, No.1, 16-25 http://bioscipublisher.com/index.php/gab 19 the stress change is small; while sun-drying is repeatedly exposed to moisture and then dried, cracks are more likely to form, ultimately affecting the quality and yield of the rice. Figure 2 Schematic illustration of the drying mechanisms affecting rice grain integrity. Mechanical drying maintains stable conditions, while sun-drying induces repeated moisture fluctuations that lead to internal stress and cracking (Adopted from Liao et al., 2020) 3.3 Granular integrity and appearance quality changes It's not just about whether the grains are broken or not; the appearance is also crucial (Zhang et al., 2018). Compared with other methods, the rice after mechanical drying has a whiter color, the grains look fuller, and there are fewer yellow grains and defective grains. For example, for a sample with an initial moisture content of 24.4%, the yellow grain rate after mechanical drying is only 0.05%, while it can reach 0.45% under sun-drying conditions. Problems such as immature grains and moldy grains are also relatively rare after mechanical processing. Sun-drying is prone to being overly dry on one side and then getting damp again, causing the grain surface to wrinkle, develop mold spots, and even get dust and impurities attached, thus affecting the appearance grade (Liu et al., 2021). This is actually related to the previous situation of a higher burst waist rate. Overall, mechanical drying is more likely to maintain the uniformity and integrity of the grains, while the unevenness and contamination brought about during sun-drying will also be reflected in the appearance. 4 Effects of Drying Methods on the Physicochemical Quality of Rice 4.1 Changes in starch structure and gelatinization properties Many people believe that the texture of rice is merely a matter of variety. In fact, the temperature during the drying process is equally crucial (Zhou et al., 2017). If the temperature is set too high, the internal structure of the starch is prone to be disrupted, resulting in an increase in amylopectin and a different final cooking state. This is particularly evident when drying at high temperatures. However, in this test, as long as the temperature is properly controlled, mechanical drying performed quite well. For example, for a sample with a moisture content of 24.4%, the initial gelatinization temperature after drying was lower, the peak viscosity was the highest, and the gelatinization temperature was approximately 67.4℃. The rice cooked with this sample expanded more easily and was more moist and smooth. On the other hand, for the samples dried by sun exposure, the gelatinization temperature moved upward and the viscosity decreased,
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