超声波辅助水酶法提取米胚油及其成分分析

Ultrasonic-Assisted Aqueous Enzymatic Extraction and Chemical Composition of Rice Germ Oil

以稻米胚芽为原料,通过超声波辅助水酶法提取富含生育酚的米胚油。通过单因素试验得到,当纤维素酶和中性蛋白酶质量比为1∶1时,复合酶添加量1.2%、酶解料液比1∶5、酶解时间3 h时,米胚油的提取率为(87.4±0.04)%。同时经透射电镜观察发现,超声波处理米胚后脂肪与蛋白分离明显。运用响应面优化发现超声各因素对米胚油提取率的影响力依次为超声功率>超声温度>超声时间。在超声温度55℃、超声功率400 W、超声时间20 min条件下,米胚油的提取率为(92.1±0.03)%。超声辅助提取的米胚油饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸含量占比分别为(20.62±0.14)%、(39.62±0.96)%、(37.46±0.43)%,超声辅助提取米胚油中γ-谷维素、植物甾醇及总生育酚的含量分别为(490.00±2.12)、(384.19±5.14)mg/100 g和(93.01±2.75)mg/100 g。

Rice germ oil rich in tocopherol was extracted by ultrasonic-assisted aqueous enzymatic method.Under the following conditions:mass ratio of cellulase to neutral protease 1:1,enzyme concentration 1.2%,material-to-liquid ratio 1:5,and hydrolysis time 3 h,the extraction efficiency was(87.4±0.04)%.Through transmission electron microscopy,it was found that obvious separation was observed between fat and protein after ultrasonic treatment of rice germ.Response surface analysis showed that ultrasonic power had the greatest effect on the extraction efficiency,followed sequentially by temperature and duration.Under the conditions of temperature of 55℃,ultrasonic power of 400 W,and time of 20 min,the extraction efficiency of rice germ oil was(92.1±0.03)%.Saturated fatty acids,monounsaturated fatty acids and polyunsaturated fatty acids accounted for(20.62±0.14)%,(39.62±0.96)%and(37.46±0.43)%of the total fatty acids in rice germ oil extracted by the ultrasonic-assisted aqueous enzymatic method,respectively.The contents ofγ-oryzanol,phytosterols and total tocopherols in the oil were(490.00±2.12),(384.19±5.14)and(93.01±2.75)mg/100 g,respectively.