包装材料对紫米贮藏品质的影响

紫米在储藏过程中易受内部及外部因素如温度、湿度、氧气等的影响,合适的包装能有效抑制紫米的陈化与霉变,本研究通过使用四种不同阻隔性的包装材料AL/PE、PA/PE单面压纹、PA/PE、PE/EVOH/PA/PE对紫米进行包装后储藏98 d,储藏期间定期测定紫米的水分含量、脂肪酸值、蛋白质含量、霉菌数量、电导率、色价、色差、电子鼻气味、形态结构等指标的动态变化并对各指标进行相关性分析。结果表明,各材料包装的紫米的水分含量有不同程度的上升而后下降、电导率先增加后降低、△E、脂肪酸值不断增大,蛋白质含量小幅上升后不断下降,霉菌含量先增加后减少至稳定,电子鼻能明显区分不同储藏期及不同包装材料中的紫米。从水分含量、△E、色价、脂肪酸值、形态结构指标来看,高阻隔材料PE/EVOH/PA/PE包装的紫米品质较稳定,从霉菌含量、电导率指标来看,PA/PE单面压纹材料包装的紫米品质较稳定。

Effect of Packaging Materials on the Storage Quality of Purple Rice

Purple rice is susceptible to the influence of internal and external factors such as temperature, humidity and oxygen during storage, and proper packaging can effectively inhibit aging and mildew of purple rice. In this study, purple rice was packed and stored for 98 days using four packaging materials with different barrier properties, AL/PE, PA/PE single-sided embossed, PA/PE, PE/EVOH/PA/PE, and the dynamic changes of moisture content, fatty acid value, protein content, mold count, electrical conductivity, color value, color difference, E-nose odor, morphological structure and other indicators of purple rice were measured periodically during storage and correlation analysis was performed for each indicator. The results showed that the moisture content of purple rice increased and then decreased, the conductivity increased and then decreased, the △E and fatty acid value increased, the protein content increased slightly and then decreased, the mold count increased and then decreased to stable, and the electronic nose could significantly distinguish purple rice in different storage periods and different packaging materials. From the moisture content, △E, color value, fatty acid value and morphological structure indexes, the quality of purple rice packed with high barrier material PE/EVOH/PA/PE was more stable, and from the indexes of mold count and conductivity, the quality of purple rice packed with PA/PE single-sided embossed material was more stable.