固定化酶催化合成EPA/DHA型磷脂的研究

Immobilized Enzyme Catalysis for the Synthesis of Eicosapentaenoic Acid/Docosahexaenoic Acid-Type Phospholipids

以大豆卵磷脂和富含二十碳五烯酸(EPA)/二十二碳六烯酸(DHA)的鱼油为底物,在固定化磷脂酶A_(1)(PLA_(1))的催化作用下,制备EPA/DHA型磷脂(EPA/DHA-PLs)。考察了PLA_(1)的固定化酶用量、水用量、反应温度、底物鱼油与磷脂质量比对EPA/DHA-PLs制备的影响,并通过响应面法分析了影响EPA/DHA-PLs合成的关键因素。研究结果表明:EPA甲酯保留时间约为54.594 min,DHA甲酯保留时间约为69.317 min,原料鱼油中EPA和DHA的总量为83.27%。EPA/DHA-PLs合成的最佳反应条件为:固定化PLA_(1)的添加量为21.81%(以底物鱼油/磷脂的总质量为基准),鱼油与磷脂质量比为5.45∶1,反应温度为54.3℃,水用量为1.08%(以底物的总质量为基准)。在此条件下,EPA/DHA的最大结合率可达65.5%。固定化PLA_(1)经5次重复使用后,剩余的酶活性仍不低于52.3%。

Eicosapentaenoic acid/docosahexaenoic acid-type phospholipids(EPA/DHA-PLs)were prepared from soybean lecithin and fish oil rich in EPA/DHA as substrates under the catalysis of immobilized phospholipase A_(1)(PLA_(1)).The effects of immobilized enzyme dosage of PLA_(1),water dosage,reaction temperature,substrate fish oil to phospholipid mass ratio on the preparation of EPA/DHA-PLs were investigated,and the key factors affecting the synthesis of EPA/DHA-PLs were analyzed by response surface method.The results showed that the retention time of EPA methyl ester was about 54.594 min,the retention time of DHA methyl ester was about 69.317 min,and the total content of EPA and DHA in raw fish oil was 83.27%.The optimal reaction parameters were determined:21.81%addition of immobilized PLA_(1)(relative to the total mass of the substrate),a substrate-to-mass ratio of 5.45∶1(fish oil/phospholipids),a reaction temperature of 54.3℃,and a water addition of 1.08%(relative to the total mass of the substrate).Under these conditions,the maximum binding rate of EPA/DHA could reach 65.5%.In addition,through the repeated use experiment of immobilized enzymes,the remaining enzyme activity of immobilized PLA_(1)was still not less than 52.3%after five repeated uses.