天美传媒

Abstract

The preparation conditions and efficiency of glucose stearic acid esters (GSAE) by lipase-catalyzed reaction in non-aqueous media were studied in this work. The available lipase of catalytic synthesis GSAE in non-aqueous media was screened from 7 commercial lipases, and the effects of various lipase andamount, variousorganic solvent and amount, molar ratio of substrates, water amount, molecular sieve 3Aamount, Agitation speed, reaction temperature, reaction time on GSAE yield were experiment, respectively. The results showed that acetone was appropriate solvent, the immobilized lipase Novozym 435 was the best catalyst for esterification reactions in acetone, and excessive water in the reaction system obviously decreased Novozyme 435 activity and GSAE yield, thus it was very necessary to add defined amount moisture absorber to remove the water of substrates, solvent and reaction process. The optimized esterification reaction conditions with 0.08 gNovozyme 435, 0.8 g3A molecular sieve, the mole ratio of stearic acid and glucose =3:1, 10 ml acetone, 150r/min shaking, 45 o C reaction temperature, 5 h reaction time were good for making the produce GSAE in non-aqueous media. In the optimized condition, the maximum reaction rate Vm was 0.749 μmol/min?g, Km was 0.0203 mmol/L and the GSAEyield rate was up to 64.11%.

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