超声辅助提取小米谷糠油工艺优化

本研究探讨了小米谷糠前处理方式和新鲜程度对小米谷糠油提取率的影响，采用超声波辅助技术，选取最适提取溶剂，通过单因素实验和响应面分析优化小米谷糠油提取工艺，并分析了小米谷糠油脂主要理化性质及其脂肪酸组成。结果表明:选用新鲜小米谷糠，经过温度为121 ℃红外加热15 min处理；选择无水乙醇作为最佳提取溶剂，浸提时间为2 h、料液比为1:6.5 g/mL、浸提温度为56 ℃，在此条件下小米谷糠油提取率为78.57%；各因素对小米谷糠油提取率的影响程度的顺序依次为:料液比>浸提温度>浸提时间；该条件下提取的小米谷糠油酸值、过氧化值均符合《食品安全国家标准 植物油》（GB2716-2018）米糠油的指标；小米谷糠油的脂肪酸主要成分为棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸，不饱和脂肪酸含量占总脂肪酸含量的90.58%，其中亚油酸含量高达72.31%。本研究提出的超声辅助无水乙醇提取小米谷糠油工艺路线是可行的，可为小米谷糠进一步开发利用提供重要的理论支撑。

Optimization of Ultrasound-assisted Extraction Process of Millet Bran Oil

This study explored the effects of millet bran pretreatment methods and fresh level on the extraction rate of millet bran oil.The ultrasonic assist technology was used,and the optimal extraction solvent was selected.The extraction process of millet bran oil was optimized through single-factor experiments and response surface analysis.The main physical and chemical properties of millet bran oil were determined,and the fatty acid composition was analyzed.The results showed that fresh millet bran need be selected and treated with infrared heating at 121℃for 15 min.Anhydrous ethanol could be used as the best extraction solvent.The optimized extraction conditions were the extraction time 2 h,the material to solvent ratio 1:6.5 g/mL,and the extraction temperature 56℃.Under this condition,the extraction rate of millet bran oil was 78.57%.The order of various factors on the extraction rate of millet bran oil was:Material to solvent ratio>extraction temperature>extraction time.The acid value and peroxide value of millet bran oil extracted under this conditions were in line with the National Food Safety Standard(GB2716-2018)indicators for rice bran oil.The main fatty acid components of millet bran oil contained palmitic acid,stearic acid,oleic acid,linoleic acid,and linolenic acid.The content of unsaturated fatty acid accounted for 90.58%of the total fatty acid content,of which the linoleic acid content was as high as 72.31%.The ultrasonic-assisted extraction process of millet bran oil with anhydrous ethanol proposed in this study was feasible and could provide important theoretical support for the further development and utilization of millet bran.