Genomics and Applied Biology 2026, Vol.17, No.1, 16-25 http://bioscipublisher.com/index.php/gab 20 resulting in a poorer performance (Li et al., 2020). Overall, mechanical drying with controllable temperature is more likely to stabilize the starch state while removing moisture, and the taste is naturally not compromised. 4.2 Response differences of protein and lipid-related indicators During drying, the nutritional components are not completely unchanged (Zhang et al., 2019). The total protein content seems to remain relatively stable, which is consistent in both the experiments and previous data. However, when the temperature is higher, the fatty acid value often increases. The reason is not complicated; high temperature makes lipolytic enzymes more active, and some fats are decomposed into free fatty acids. With a larger quantity, the rice grains are more prone to deterioration and may even produce substances with an unpleasant smell. In this study, the samples dried at high temperature and stored showed significantly higher fatty acid values than the low-temperature treatment group, and the degree of oil oxidation was also more severe. Although the protein content difference was not obvious, its structure may have changed. From this, it can be seen that temperature control cannot be ignored. Lowering the temperature is more conducive to maintaining quality, while excessively high temperature will instead affect the taste (Liu et al., 2021). 4.3 The mechanism of the effects of drying temperature and rate on physicochemical properties Many people think that drying means removing water. In fact, once the temperature and speed increase, changes have already occurred inside the grains (Zhou et al., 2017). It's not just about losing water on the surface; under high temperatures, starch granules will be disrupted, short-chain molecules will increase, and the gelatinization temperature and viscosity curve will shift accordingly. Sometimes the problem doesn't stop there; proteins will also denature under high temperatures and combine with starch. Once this structure is formed, the starch's ability to absorb water and expand is limited, and the gelatinization performance naturally weakens. After long-term high-temperature treatment, the phenomenon of decreased viscosity and retrogradation value is also common (Li et al., 2020). If drying is only focused on speed, these changes are easily overlooked. Therefore, methods such as staged heating and slow cooling are actually more conducive to balancing efficiency and taste. 5 Effects of Drying Methods on Eating Quality and Sensory Characteristics 5.1 Differences in texture and taste of rice Many people only realize the impact of the drying method when they taste the rice (Li et al., 2020). Comparing the data would be more intuitive. The mechanically dried samples performed better in terms of viscosity and stability. Taking rice with a moisture content of 24.4% as an example, the peak viscosity and disintegration value after drying were both higher. The cooked rice was sticky but not greasy, and had elasticity. The values of the samples dried in the sun were significantly lower, and the taste was thus more loose (Zhang et al., 2018). The sensory scoring was actually not off track. The rice dried mechanically and those left in the shed were more recognized in terms of appearance and flavor. The sun-dried group often ranked lower. Overall, mechanical drying is more likely to retain the glutinous aroma and elasticity, while during the sun-drying process, the rice becomes harder and its stickiness decreases more frequently. 5.2 Preservation of aroma and flavour changes characteristics Often, the rice aroma is subtly altered during the drying process (Figure 3) (Tan et al., 2025). The aroma of rice is inherently fragile and can easily deteriorate over time and in an uncontrolled environment. In experiments, it can be observed that mechanical drying with stable temperature control is more likely to preserve the original aroma; while prolonged sun-drying not only leads to a loss of aroma but may also introduce off-flavors. In sensory scoring, the sun-dried group had the lowest flavor score, which is related to exposure to dust, pollutants, and excessive water loss (Pang et al., 2021). In contrast, samples treated with mechanical drying and proper storage in sheds had cleaner and more natural aromas, and received higher overall evaluations. From this perspective of smell, mechanical drying truly has an advantage.
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