海洋微藻中EPA和DHA的超临界CO_2提取方法研究

A STUDY ON SC-CO_2 EXTRACTING TECHNOLOGY OF EPA AND DHA FROM MARINE MICRO-ALGAE

用超临界CO_2萃取海洋微藻中的EPA和DHA，选用乙酸乙酯为改性剂，通过正交试验确定了工作压力、温度、CO_2消耗量和改性剂添加量等工艺条件的最优化组合，对日本小球藻Chlorellahiralaii、钝顶螺旋藻Spirulinaplatensis和亚心形扁藻Platymonassubcordiformis进行提取试验，并与直接酯化法、Bligh－Dyer法、索氏抽提法和乙醇－乙烷法等溶剂法作对比。以提取效率最高的直接酯化法为基础，超临界萃取法对日本小球藻中ω－3脂肪酸二十碳五烯酸（EPA）的提取率为92．1％，二十二碳六烯酸（DHA）为89．4％，对钝顶螺旋藻和亚心形扁藻的提取率也达到90％左右，高于其他溶剂法，产物中EPA和DHA的纯度亦优于溶剂法。

EPA and DHA in marine micro-algae were extracted with supercriticalCO_2(SC-CO_2). Ethyl acetate was chosen as a polar alternative. Suitable technologyconditions, such as pressure, temperature and consumption of CO_2, for EPA and DHAextraction from Platymoras subcordiformis, Chlorella hirataii and Spirmlina platensiswere determined by experiment of orthogonal composition design. Compared withmethods of Bligh-Dyer, ethanol-hexane mixed solvent extraction and Soxhlet extraction,SFE is the best one in terms of the extracting rate and product quality. Theextracting rates of EPA and DHA from Chlorella hirataii were 92.1% and 89.4%respectively; and those from the other two kinds of micro-algae were about 90%.