Optimization of enzymatic esterification of oleic acid with glycerol for the preparation of triglycerides by response surface methodology

The triglycerides were synthesized from glycerol and oleic by Novozym 435 lipase catalysis in a solventfree system, and the reaction conditions were optimized by response surface methodology ( RSM) . The substrate molar ratio, reaction time, reaction temperature and enzyme load strongly affected triglyceride content ( p < 0.05) , and substrate molar ratio had the most significant effect on triglyceride content ( p = 0.0104) . The optimum conditions were as follows: substrate molar ratio ( oleic acid / glycerol) 2.92 ∶ 1, reaction time 12 h, reaction temperature 98 ℃, and enzyme load 2.96% ( based on the total weight of oleic acid and glycerol) . Under the optimum conditions, triglyceride content was 90.88% ± 1.56%, esterification degree was 93.09% ± 1.42%.