该研究以海藻油为原料,通过醇解法合成了2-二十二碳六烯基单甘脂(2D-MAG),并分别对脂肪酶种类、藻油与乙醇的底物摩尔比、反应时间、反应温度和脂肪酶利用次数等影响因素进行了研究。结果表明,藻油中sn-2位脂肪酸以n-3 PUFA (62.26%)含量最多,是合成sn-2长链结构脂2D-MAG较为理想的原料。催化藻油合成脂肪酶的催化活性由高到低依次为:Lipozyme RM IM >Novozym 435(质量分数)>Lipozyme TL IM >Newlase F > Lipase AK > Lipase AY。当藻油与乙醇底物摩尔比为1∶40、酶添加量为10%(质量分数),反应时间为3 h、反应温度为35 ℃条件下利用Lipozyme RM IM催化藻油醇解更有利于2D-MAG合成产物的积累,在此条件下催化合成的2D-MAG产物得率为45.36%。Lipozyme RM IM脂肪酶在重复第6次后,2D-MAG的含量显著低于前5次(P<0.05),表明随着反复利用次数的增加Lipozyme RM IM脂肪酶催化活性在后期显著弱化。该研究将为相关sn-2长链多不饱和脂肪酸功能性结构脂的制备和改性研究提供参考。
In this study, 2-monoacyl glycerolrich in 2D-MAG was synthesized from algal oil by ethanol, and the types of lipase, the molar ratio of algal oil to ethanol, reaction time, reaction temperature and utilization times of lipase were studied. The results showed that n-3 PUFA (62.26%) was the most abundant fatty acid of sn-2 in algal oil, and it was an ideal raw material for the synthesis of the sn-2 long-chain structural lipid 2D-MAG.The catalytic activity of lipozyme RM IM >Novozym 435 >lipozyme TL IM >Newlase F > Lipase AK > Lipase AY was in the order of high to low. Lipozyme RM IM was used to catalyze the alcoholysis of alga oil under the conditions of molar ratio of alga oil/ethanol of 1∶40, enzyme addition of 10%, reaction time of 3h and reaction temperature of 35 ℃, which was more conducive to the accumulation of 2D-MAG synthesis products. Under these conditions, the yield of 2D-MAG was 45.36%. After the 6th repetition of Lipozyme RM IM lipase, the content of 2D-MAG was significantly lower than that of the previous five times (P<0.05), indicating that although the overall catalysis of Lipozyme RM IM lipase was stable, its catalytic activity significantly weakened with the increase of repeated use. The results will provide references for the preparation and modification of functional structural lipids of related sn-2 long-chain polyunsaturated fatty acids.
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