Abstract: This study aimed to solve the problem of fast aging of rice during storage in plum rain season environment. High-quality rice of the ‘Nanjing 9108’ cultivar was packaged with a nano-antibacterial material prepared in our laboratory or a normal material (control) and stored in a simulated plum rain season environment (38 ℃ and 92% RH). Samples were withdrawn every 7 days for the measurement of α, β-amylase, catalase and lipase activities, fatty acid and total acid contents, the cross-sectional microscopic structure of rice endosperm and starch pasting properties. The results showed that nano-packaging led to a slower decline in α, β-amylase and catalase activities of rice compared with normal packaging. In addition, nano-packaging delayed the time to reach the lipase activity peak by two weeks and simultaneously mitigated the accumulation of fatty acids and total acid. More importantly, there was no evident difference in the cross-sectional microscopic structure of rice endosperm between nano-packaging and fresh rice, implying that nano-packaging could retard rice aging. Moreover, starch pasting characteristics of nano-packaged rice significantly differed from those of normally packaged rice. This study confirmed that the nano-packaging could retard rice aging in high temperature and humidity environment, inhibit the changes in related enzyme activities and chemical components, and consequently maintain the storage quality of rice.

Key words: rice, nano-packaging, aging, enzyme activity