Studies On Lipase-Catalyzed Synthesis Of Sugar Esters In Non-Aqueous

In this paper, we attempted to synthesize sugar esters of fatty acids using immobilized lipase in organic solvents and solvent-free system media, according to non-aqueous enzymology.Compared the activities of 5 sorts of lipases from different source in synthesis of fatty acid esters and hydrolysis of olive oil, 3 sorts of lipases are better. Compared the stability and the activities of 3 sorts of Upases in different media, organic solvents and CAL lipase are best.Using CAL lipase, sucrose-laurate esters were synthesized in the 8 sorts of different solvents, the best solvent was tert-butanol, dosage of solvent 5 ml. Temperature, molar ratio of sugar to acid, pH, initial water activity, dosage of lipase, molecular sieve and rotation speed were investigated, the optimum conditions as follows: 45 C , sugar to acid 1:3, pH7.5, initial water activity 0.75, dosage of lipase 50mg, 1g molecular sieve, rotation speed 150r/min, after reaction for 32h, conversion of lauric can reach 69%.Through adding different salt hydrate pairs to reaction to control water content in solvent-free system, CAL lipase can maintain higher activity, dosage of Na4P2O7 (10/0)H2O is 0.6/2.68g substrates. Else reaction conditions were also studies, as follows: 50 C, sugar to acid 1:5,pH7.5, initial water activity 0.75 , dosage of lipase 200mg, rotation speed 200r/min, after reaction for 32h, conversion of lauric can reach 69%.Reaction products were qualitatively analyzed through TLC and HPLC; we preliminary consider it sucrose mono-laurate, we identify it by IR farther, results show that there is a strong absorb peak in 1739-1cm place that it is a character peak of esters, it proved sucrose esters.