Abstract:
To investigate the quality changes of indica rice stored under different temperature conditions after nitrogen modified atmosphere sealing and unsealing, the indica rice was packaged under 99% N
2 and stored at 25 ℃ for 180 days before unsealing. Subsequently, the samples were transferred to low temperature (15 ℃), room temperature (25 ℃), and high temperature (35 ℃) conditions for an additional 180 days of storage. The physicochemical quality, processing quality, microscopic structure of endosperm, cooking quality, and textural characteristics of indica rice were measured and analyzed. The results showed that during 180 days after nitrogen modified atmosphere unsealing, the fatty acid value, amylose content, water absorption capacity, swelling rate, hardness, and chewiness of cooked rice increased under all three temperature conditions. Conversely, moisture content, peroxidase (POD) activity, brown rice rate, head rice rate, pH value of rice soup, adhesiveness, and elasticity of rice all showed a decreasing trend. Except for amylose content and water absorption rate of rice stored at 15 ℃, the other indexes were better than those stored at 25 ℃ and 35 ℃, with the grain structure remaining relatively dense and complete. Correlation analysis revealed that the storage temperature of rice had a significant negative correlation with moisture content, POD activity, brown rice rate, head rice rate, and elasticity of rice, with the absolute correlation coefficient of 0.51 and above. The storage temperature of rice showed a significant positive correlation with fatty acid value, hardness, and adhesiveness of rice, with correlation coefficient of 0.54 and above. After nitrogen modified atmosphere unsealing, low temperature storage could slow down the quality deterioration of indica rice by delaying changes in biochemical indexes. The research results provide a theoretical basis for the scientific storage of indica rice after nitrogen modified atmosphere unsealing.