低温储藏解除后长粒型籼稻的品质变化和动力学分析

Quality change and kinetic analysis of long-grain indica rice after low temperature storage

中文关键词:  长粒型籼稻  低温储藏  品质指标  相关性分析  动力学分析

英文关键词:long-grain indica rice  low temperature storage  quality index  kinetic analysis

中文摘要:

      目的 探讨长粒型优质籼稻低温储藏解除后的品质变化。方法 以广西桂林新收获的长粒型优质籼稻为对象, 对低温储藏解除后的稻谷进行低温(15℃)、常温(25℃)和高温(35℃)储存180 d, 每20 d取样进行品质指标检测, 并进行动力学分析。结果 在3个温度条件下, 稻谷的出糙率、整精米率、水分含量、发芽率、过氧化物酶活性、多酚氧化酶活性和品尝评分值呈下降趋势, 黄粒米率、直链淀粉含量、丙二醛含量、脂肪酸值呈上升趋势, 15℃条件下继续储存可以有效地延缓稻谷品质的劣变, 低温解除前后的温差对稻谷储存前期品质变化影响较大。相关性分析表明, 储藏时间和温度与稻谷各品质指标均呈显著相关性; 温差与稻谷各品质指标的相关性不强。动力学分析结果表明不同温度下水分含量、丙二醛含量和脂肪酸值的变化均符合零级动力学模型, 在相同储藏温度条件下, 丙二醛含量的活化能均小于水分含量和脂肪酸值的活化能。结论 稻谷低温解除后, 短时间储存稻谷应避免温差较大, 长时间储存应在较低温度下储存, 既能延缓稻谷品质劣变, 又能节约储存成本。丙二醛含量可作为低温解除后稻谷品质变化的早期预测参考指标。

英文摘要:

      Objective To study the quality change of long-grain high quality indica rice after low temperature storage. Methods After low temperature storage, the newly harvested long-grain high-quality indica rice from Guilin, Guangxi, was stored at low temperature (15℃), normal temperature (25℃) and high temperature (35℃) for 180 days, and the samples were taken every 20 days for quality index detection and dynamic analysis. Results Under the 3 temperature conditions, rice emergence rate, finishing rice rate, water content, germination rate, peroxidase activity, polyphenol oxidase activity and taste score showed a downward trend, while yellow grain rice rate, amylose content, malonaldehyde content and fatty acid value showed an upward trend. Storage at 15℃ could effectively delay the deterioration of rice quality. The temperature difference before and after low temperature relief had a great influence on the quality change of rice in the early stage of storage. The correlation analysis showed that the storage time and temperature were significantly correlated with each quality index of rice. The correlation between temperature difference and rice quality index was not strong. The kinetic analysis results showed that the changes of water content, malondialdehyde content and fatty acid value at different temperatures were consistent with the zero-order kinetic model, and the activation energy of malondialdehyde content was lower than that of water content and fatty acid value at the same storage temperature. Conclusion After the low temperature storage of rice is lifted, the short-term storage of rice shall avoid large temperature difference, and the long-term storage shall be stored at a lower temperature, which can delay the deterioration of rice quality and save storage costs. Malondialdehyde content can be used as an early prediction index for rice quality change after low temperature removal.