The Study On Enzymatic Synthesis Of Maltose Stearic Acid Ester

Based on enzymology theory,the lipase-catalyzed synthesis of maltose fatty acid ester by transesterification and esterification reaction has been studied.Compared the activities of 6 sorts of lipases from different soures in synthesis of fatty acid esters and choose the 4 betters.In comparing the different media lipase-catalyzed maltose stearic acid ester synthesis activities and found that only Novozym435 have the catalytic ability,and the best catalytic esterification lipase Novozym435 is elected.Using Novozym 435 lipase,maltose fatty acid ester is synthesized in sorts of different solvents,the best solvent is the mixture solution of tert-butyl alcohol and n-hexane. Reaction time,reaction temperature,reaction materials ratio,water content,dosageof lipase have been investigated,the optimum conditions are as follows:77℃,reaction materials ratio 1:1,dosage of lipase 12.0%,10.0%of water,after reaction for 24 hours,rate of conversion can reach 91.3%.By n-hexane,tert-butyl alcohol system,using oil-water separator in order to remove water,adding Novozym435 to lipase-catalyz the reaction of maltose syrup and stearic acid, while reaction time,reaction temperature,reaction materials ratio,water content,dosageof lipase have been investigated,The optimum conditions are as follows:75℃,reaction materials ratio 1:1,dosage of lipase 10.0%,10.0%of water,after reaction for 24 hours,rate of conversion can reach 72.6%.Reaction products are qualitatively analyzed through TLC;we preliminary consider it maltose stearic acid ester,and we identify it by IR farther,results show that there is a strong absorb peak in 1740 cm^-1 place that it a character peak of esters,that proves the products are sucrose esters.