山核桃油的超临界CO_2萃取工艺及其特性研究

Study on Supercritical CO_2 Fluid Extraction Technology and Properties of Carya kernel Oil

对超临界CO2萃取山核桃油的工艺条件进行了实验。单因素试验结果表明,粉碎粒度20～40目(孔径0.9～0.4mm)、萃取时间最短2h、萃取压力大于30MPa、萃取温度35～45℃时,山核桃油的萃取率较高。在单因素试验的基础上用正交试验进行了工艺参数优化,其适合工艺条件为:萃取时间2.5h,萃取压力30MPa,粉碎粒度30目(孔径0.6mm),萃取温度40℃。在该萃取条件下,山核桃油的提取率为95.74%。不同方法提取山核桃油主要理化特性测定结果表明,超临界CO2萃取的山核桃油具有碘价高、皂化价低、酸价低等特点,质量较好。采用气相色谱仪对油脂的脂肪酸组成及含量进行了测定。结果表明,不饱和脂肪酸含量为93.55%,其中油酸、亚油酸和亚麻酸的含量分别为68.01%、23.21%和2.11%。

This experiment studied the supercdtical CO2 fluid extraction（SFE-CO2） technology of Carya kernel oil（CKO）. The results showed the extraction rate was high when the grind degree was 0.9～0.4 mm（20～40 mesh）, time longer than 2 h, pressure higher than 30 MPa and temperatures 35 ～45℃. On basis of single factor test, the orthogonal test was used in optimization of technological parameters. The feasible technological conditions were 2.5 h, 30 MPa, 0.6 mm（30 mesh）and 40℃. By the above conditions, the extraction rate could be 95.74%. The effects of extraction methods on CKO physieochemical properties were researched. Compared with the ether extraction and the aqueous extraction, the obtained oil by SFE-CO2 has the following several traits： the high iodine, the low acid value, the low sponification value and the low peroxide and so on. By means of gas chromatography （GC）, 93.55% unsaturated fatty acid were determined in the oil, including oleic acid 68.01%, linoleic acid 23.21% and linolenic acid 2.11%.