响应面优化粟米糠油溶剂萃取工艺及理化性质分析

Optimization of Extraction of Millet Bran Oil by Response Surface Design and Analysis of Physico-chemical Properties

以粟米糠为原料,采用正己烷为提取剂,对粟米糠油进行提取,并分析粟米糠油的理化特性和脂肪酸组成。在单因素试验的基础上,通过Box-Behnken试验设计对提取工艺进行响应面优化。结果表明,最佳提取工艺条件为:料液比1∶7(g/m L)、提取时间6 h、提取温度55℃。在此条件下,粟米糠油的实际提取率为83.3%,与理论值基本吻合。所得粟米糠油的凝固点19.0℃、酸值5.7 mg KOH/g、过氧化值2.1 mmol/kg、皂化值185.1 mg KOH/g、碘值118.9 g I2/100 g。通过气相色谱-质谱法确定了10种脂肪酸,不饱和脂肪酸含量为82.5%,其中亚油酸含量63.6%、油酸含量14.8%、α-亚麻酸含量2.7%。

In this study, millet bran oil was extracted from millet bran with n-hexane, and its physico-chemical properties and fatty acid composition were analyzed. The extraction process was optimized by Box-Behnken design using response surface methodology(RSM) on the basis of single factor experiments. Results indicated that the optimal extraction process was found to be extraction at 55 ℃ for 6 h with a material/liquidratio of 1:7(g/m L). Experiments conducted under the optimized conditions resulted in an extraction yield of 83.3%, which was consistent with the theoretical value. The freezing point of millet bran oil was 19.0 ℃, the acid value was 5.7 mg KOH/g, the peroxide value was 2.1 mmol/kg, the saponification value was 185.1 mg KOH/g and the iodine value was 118.9 g I2/100 g. In addition, 10 fatty acids were identified in the millet bran oil, and the total content of unsaturated fatty acids was 82.5%, including 63.6% linolic acid, 14.8% oleic acid and 2.7%α-linolenic acid.