不同方法提取‘凤丹’牡丹籽油品质比较

采用超临界CO_2萃取法、冷榨法和有机溶剂浸提法对‘凤丹’牡丹(Paeonia?ostii?‘Fengdan’)籽油进行提取,研究不同提取方法对牡丹籽油的出油率、理化特性、脂肪酸组成及体外抗氧化能力的影响。结果表明:3种方法中以有机溶剂浸提法的出油率最高(28.61%),超临界CO_2萃取居中(28.17%),冷榨法最低(19.14%);3种提取方法对牡丹籽油的皂化值、折光指数、相对密度影响差异不大,而对牡丹籽油的酸值、过氧化值、碘值、水分及挥发物和颜色等方面影响差异较大;3种方法对牡丹籽油主要脂肪酸组成和相对含量无显著影响,对体外抗氧化能力有显著影响,以指标1,1-二苯基-2-三硝基苯肼自由基清除率和半最大效应浓度(EC_(50))计,体外抗氧化能力依次为有机溶剂浸提法冷榨法超临界CO_2萃取法。3种方法各有特点,相比之下冷榨法成本少,操作简单,工艺流程简单,安全性好,更适宜牡丹籽油提取。

Comparison of Different Extraction Methods for Seed Oil from the ‘Fengdan’ Peony Cultivar

Peony seed oil from the ‘Fengdan’ cultivar was extracted by supercritical CO2 extraction, cold pressing, and organic solvent extraction, respectively, in order to explore the effect of different extraction methods on oil yield, physicochemical properties, fatty acid composition and antioxidant capacity in vitro. The results showed that organic solvent extraction produced the highest oil yield (28.61%), supercritical CO2 extraction was in the middle (28.17%), and the lowest oil yield (19.14%) was obtained by cold pressing. There were no significant variations in saponification value, refractive index or relative density among the three extracted oils, while considerable variations in acid value, peroxide value, iodine value, moisture and volatiles, and color were observed. Moreover, these oil samples had nearly identical fatty acid composition and content as measured by gas chromatography-mass spectrometry (GC-MS). In addition, their antioxidant activities in vitro were significantly different and followed the decreasing order of organic solvent extraction > cold pressing > supercritical CO2 extraction in terms of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging rate and EC50 (concentration for 50% of maximal effect). In conclusion, each method has both advantages and disadvantages for the extraction of peony seed oil. Cold pressing is advantageous with respect to lower cost, easier operation, simpler process, and higher safety over the two other methods and therefore it is more suitable for the extraction of peony seed oil.