关键词: 大米, 高温高湿, 储藏, 纳米包装

Abstract: Objective: A nano-packaging material containing nano-silver, nano-titanium dioxide, nano-attapulgite and nano-silica was prepared, and the effect of this material on the preservation of the rice cultivar Huaidao 5 at high temperature (37 ℃) and high humidity (relative humidity 85%) was studied. Methods: The rice was packaged in nanocomposite pouches, polyethylene (PE) pouches and not packaged and then stored for 10 weeks, respectively. The effects of different packaging materials on color difference, O2 and CO2 percentages inside packages, peroxide value (POV), catalase activity, and the contents of carbonyl groups, sulfhydryl groups and disulfide bonds were investigated. Meanwhile, the flavor of rice was measured by electronic nose during storage. Results: The low O2 and high CO2 atmosphere was maintained inside nano-packages, and the percentages of O2 and CO2 were 16.4% and 1.4% after 10 weeks of storage, respectively. The nano-packaging material effectively maintained the original color and flavor of rice at the end of storage. Nano-packaging delayed the increase of peroxide value and the decrease of catalase activity during the storage period. Meanwhile, the increase of carbonyl groups and disulfide bonds and the decrease of sulfhydryl groups indicated that the oxidation of rice protein was delayed by nano-packaging. Conclusion: The nano-packaging material has antibacterial effects and can maintain low O2 content and high CO2 content in packages, thereby inhibiting mold growth, decrease catalase activity, and reduce peroxide production. Furthermore, it can also attenuate the oxidation of fat and protein and efectively maintain the original color and flavor of rice.

Key words: rice, high temperature and high humidity, storage, nano-packaging