We compared four esterifiable enzymes. The lipase Novozym 435 possessed the highest activity for the conjugated linoleic acid esterification during the synthesis of triglycerides. The triglycerides were synthesized by...We compared four esterifiable enzymes. The lipase Novozym 435 possessed the highest activity for the conjugated linoleic acid esterification during the synthesis of triglycerides. The triglycerides were synthesized by esterification of glycerol and conjugated linoleic acid （CLA） in a no-solvent system using lipase catalysis. We investigated the effects of temperature, enzyme concentration, water content, and time on esterification. Enzyme and water concentrations of up to 1% of the total reaction volume and a system temperature of 60℃ proved optimal for esterification. Similarly, when the esterification was carried out for 24 h, the reaction ratio improved to 94.11%. The esterification rate of the rotating screen basket remained high （87.28%） when the enzyme was re-used for the 5th time. We evaluated the substrate selectivity of lipase （NOVO 435） and determined that this lipase prefers the 10,12-octadacadienoic acid to the 9,11-octadecadienoic acid.展开更多
基金Supported by the High Technology Research and Development Program of China (No 2007AA091905)the Technical Program of Municipal Technology Bureau Qingdao (No 04-2-JS-117)
文摘We compared four esterifiable enzymes. The lipase Novozym 435 possessed the highest activity for the conjugated linoleic acid esterification during the synthesis of triglycerides. The triglycerides were synthesized by esterification of glycerol and conjugated linoleic acid （CLA） in a no-solvent system using lipase catalysis. We investigated the effects of temperature, enzyme concentration, water content, and time on esterification. Enzyme and water concentrations of up to 1% of the total reaction volume and a system temperature of 60℃ proved optimal for esterification. Similarly, when the esterification was carried out for 24 h, the reaction ratio improved to 94.11%. The esterification rate of the rotating screen basket remained high （87.28%） when the enzyme was re-used for the 5th time. We evaluated the substrate selectivity of lipase （NOVO 435） and determined that this lipase prefers the 10,12-octadacadienoic acid to the 9,11-octadecadienoic acid.
文摘T1脂肪酶是一种新型耐热脂肪酶,能催化油酸与甘油的酯化反应。当甘油与油酸物质的量比2∶1、酶的添加量9.7 U/g(占总反应物质量)、缓冲液的添加量5%(占总反应物质量)和转速542r/min时,考察不同反应温度(40、50、60℃)下T1脂肪酶催化油酸与甘油酯化反应的动力学。结果表明,T1脂肪酶催化该酯化反应活化能为20.272 9 k J/mol;当反应温度较低(40℃)时遵循准一级反应;随着反应温度升高到较高范围(50、60℃),则变为准二级反应。
