小米糠油的超声辅助提取工艺及GC-MS分析

Optimization of Ultrasonic-Assisted Extraction of Millet Bran Oil and GC-MS Analysis of Its Fatty Acid Composition

以小米糠为原料,利用超声波辅助提取小米糠油,通过单因素及正交试验,研究提取溶剂、料液比、提取温度、提取时间、提取次数、超声频率和超声功率对出油率的影响,确定超声波辅助提取小米糠油的最佳工艺条件,并用气相色谱-质谱(GC-MS)分析小米糠油的脂肪酸组成。结果表明:最佳提取工艺参数为热水饱和的正丁醇为提取溶剂、超声频率40kHz、超声功率300W、料液比1:10(g/mL)、提取温度60℃、提取时间20min、提取次数2次,在此工艺条件下小米糠油的提取率为87.68%。GC-MS分析显示,小米糠油的主要成分是棕榈酸13.08%、亚油酸56.73%、油酸19.78%、硬脂酸5.41%,另外还含有0.80%β-谷甾醇,说明小米糠油是一种营养保健的高级食用油脂。

Ultrasonic-assisted extraction was used to extract essential oil from millet bran. The effects of extraction solvents, solid-to-liquid ratio, extraction temperature and repeated extraction cycles and extraction duration, ultrasonic frequency and ultrasonic power on the yield of millet bran oil were investigated by using one-factor-at-a-time and orthogonal array designs. The results showed that the optimal extraction conditions were determined as follows： n-butyl alcohol as extraction solvent, solid-to-liquid ratio of 1：10 （g/mL）, two repeated cycles of extraction at 60 ℃ for 20 min, ultrasonic frequency of 40 kHz and ultrasonic power of 300 W. Under these conditions, the yield of millet bran oil was 87.68%. The major fatty acids of millet bran oil were 13.08% hexadecanoic acid, 56.73% 9,12-octadecadienoic acid, 19.78% 9-octadecenoic acid, and 5.41% octadecanoic acid, as demonstrated by GC-MS analysis. Additionally, 0.8% β-sitosterol was also detected. These results indicate that the millet bran oil is a healthy and nutritional cooking oil.