(503e) Lipase-Catalyzed Synthesis of Plant Sterol Esters and Its Kinetic Studies

Plant sterol esters (phytosterols esters) have been shown to have beneficial effects on lowing plasma cholesterol level by inhibiting the absorption of cholesterol from small intestine and have been used as functional food ingredients. The plant sterol esters via lipase-catalysed esterification with fatty acids are suitable for applying in food ingredients. Lipase-catalyzed esterification reactions are important area of research in non-aqueous enzymology. In this work, five lipases as a biocatalyst were used to synthesis plant sterol esters and find AY30G (from Candida rugosa) was the most effective for synthesis of plant sterol esters , the optimum parameters of preparation of plant sterol esters were obtained : ratio of FA to plant sterol 2:1 , amount of catalyst 5% of plant sterol and FA , the amount of molecular Sieve was 60mg/ml and reaction temperature 45°C , the conversion was to be 90.24%. Lipase catalyzed esterification in non-aqueous reaction kinetics study on the industrial application of plant sterol esters instructive, through the experiment and used the nonlinear regression analysis the method to establish dynamics model to the lipase synthesis plant sterol esters reaction process. A simplified model based on Ping-Pong Bi-Bi with substrate competitive inhibition by sterol was found to fit the initial rate data and the kinetics parameters were evaluated.