不同提取方法对米糠油品质的影响

The effect of different extraction methods on the quality of rice bran oil

米糠是稻米加工的副产物,包含稻米60%以上的营养物质,可以用来加工提取米糠油.目前我国油脂70%依赖国外进口,存在潜在的市场风险,因此提高粮油自给率迫在眉睫.以米糠为原料,研究分析了不同提取方法对米糠油品质的影响,并通过扫描电镜观察不同提取方法处理后米糠表面的形态特征.结果表明:在米糠油提取过程中,石油醚提取效果优于正己烷和异丙醇.同时通过微波辅助处理后,溶剂提取米糠油的出油率显著升高,其中石油醚-微波提取米糠油,出油率可达到8.84%,过氧化值为0.93 mmol/kg;不同溶剂提取后,米糠油的酸价高低顺序为异丙醇>正己烷>石油醚;通过气相色谱分析发现,不同提取方法对米糠油脂肪酸组成影响不显著,但对甘油酯组成有一定的影响;在通过辅助处理后,米糠油的谷维素含量出现波动,生育酚的总酚含量明显升高,异丙醇-微波处理提取的米糠油中总酚含量最大可达到23.64 mg/100 g,说明辅助方法有利于提取米糠中的生育酚.研究结果不仅为提高我国粮油自给率提供了新的思路,还为米糠的加工利用提供了技术参考.

Rice bran is the by-product of rice processing,containing more than 60%of the nutrients of rice,can be used to process and extract rice bran oil.At present,70%of China′s oils and fats depend on foreign imports,and there is a potential market risk,so it is urgent to improve the self-sufficiency rate of grain and oil.In this study,the effect of different extraction methods on the quality of rice bran oil was studied and analyzed by using rice bran as raw material,and the morphological characteristics of the surface of rice bran after treatment with different extraction methods were observed by scanning electronic microscopy.The results show that petroleum ether is better than hexane and isopropyl alcohol in the extraction process of rice bran oil.Meanwhile,the oil yield of solvent-extracted rice bran oil is significantly higher after microwave-assisted treatment,among which the oil yield of petroleum ether-microwave-extracted rice bran oil has reached 8.84%with peroxide value of 0.93 mmol/kg;the acid values of rice bran oil in the order of isopropyl alcohol>hexane>petroleum ether after different solvents extraction;it is found by gas chromatography analysis that the effects of different extraction methods on the fatty acid composition of rice bran oil is not significant,but has some effects on the composition of glycerides;after the auxiliary treatment,the oryzanol of rice bran oil has changed,and the total phenolic content of tocopherol has increased significantly,and the maximum total phenolic content in rice bran oil extracted by isopropanol-microwave treatment has reached 23.64 mg/100 g,which indicates that the auxiliary method is beneficial to the extraction of tocopherol in rice bran.This study not only provides a new idea for improving the self-sufficiency of grain and oil in China,but also provides a technical reference for the processing and utilization of rice bran.