青稞酒糟脂溶性成分超临界CO2提取工艺优化及其组成分

Optimization of the Supercritical CO2 Extraction Process and Composition Analysis of the Fat-soluble Components of Highland Barley Brewer’s Spent Grains

摘要:

以青稞酒糟为研究对象，采用超临界CO2萃取法提取青稞酒糟脂溶性成分，利用单因素和响应面试验确定最佳的提取条件，并用气相色谱-质谱联用法（Gas Chromatography-Mass Spectrometer，GC-MS）对酒糟脂溶性成分中脂肪酸和甾醇的组成及含量进行分析。结果表明，青稞酒糟脂溶性成分的最佳提取条件为：装料系数0.6，萃取压力25 MPa，萃取温度40 ℃，萃取时间120 min，脂溶性成分的提取得率达5.50%。通过谱图解析和峰面积归一化法得出，酒糟脂溶性成分中共分离鉴定出18种脂肪酸，主要为亚油酸、棕榈酸和油酸，不饱和脂肪酸（Unsaturated Fatty Acid，USFA）含量为67.09%，单不饱和脂肪酸（Monounsaturated Fatty Acid，MUFA）含量为19.66%，多不饱和脂肪酸（Polyunsaturated Fatty Acid，PUFA）含量高达47.43%；此外，脂溶性成分中共分离鉴定出9种甾醇，β-谷甾醇的相对含量最高，为52.78%，其次是樟脑酚即菜油甾醇（12.80%）和豆甾醇（5.10%）。该研究可为青稞酒糟的深度开发和高值化利用提供理论依据。

Abstract:

The fat-soluble components of highland barley brewer’s spent grains were extracted via supercritical CO2 extraction, and the optimal extraction conditions were determined using single factor and response surface experiments. The composition and content of fatty acids and sterols in the fat-soluble components of brewer’s spent grains were analyzed using gas chromatography-mass spectrometry (GC-MS). The optimal extraction conditions for the fat-soluble components of highland barley brewer’s spent grains were as follows: loading coefficient, 0.6; extraction pressure, 25 MPa; extraction temperature, 40 ℃; and extraction time, 120 min, which led to an extraction rate of 5.50%. According to spectral analysis and peak area normalization method, 18 types of fatty acids were isolated and identified from the fat-soluble components of brewer’s spent grains, mainly linoleic acid, palmitic acid, and oleic acid. The content of unsaturated fatty acids (USFA) was 67.09%, that of monounsaturated fatty acid (MUFA) was 19.66%, and that of polyunsaturated fatty acid (PUFA) was 47.43%. Nine sterols were isolated and identified as fat-soluble components. β-sitosterol accounted for the highest relative content (52.78%), followed by camphorol (12.80%) and stigmasterol (5.10%). This study may provide a theoretical basis for the in-depth development and high-value utilization of highland barley brewer’s spent grains.