植物甾醇酯的脂肪酶促催化合成及其分析表征

运用中心组合设计，以酯化率为考察指标，对脂肪酶(由Candida rugosa生产)催化合成植物甾醇油酸酯进行优化研究。通过甾醇酯化率的响应面分析，研究反应温度、反应时间、底物物质的量的比(油酸:植物甾醇)和酶量及其交互作用对酯化反应的影响，构建相应的回归模型，并进行验证。结果表明：反应温度41℃、反应时间19h、底物物质的量的比2.4:1、加酶量7%为最佳条件，验证实验酯化率可达77.43%。并采用红外光谱和气相色谱-质谱对甾醇酯进行有效检测分析及结构表征。

Lipase-Catalyzed Synthesis and Characterization of Phytosterol Esters

The synthesis of phytosterol oleic acid esters catalyzed by lipase from Candida rugosa in organic medium was investigated.The reaction conditions were optimized by response surface methodology(RSM) using the degree of esterification(DE) as the evaluation index.A quadratic regression equation of esterification rate on the basis of independent variables such as temperature,reaction time,oleic acid-phytosterol ratio and catalyst amount was established.The results indicated that the optimal synthesis conditions were reaction temperature of 41 ℃,reaction time of 19 h,oleic acid-phytosterol ratio of 2.4:1 and catalyst amount of 7%.Under the optimal reaction conditions,the DE between phytosterol and oleic acid reached up to 77.43%.In addition,the phytosterol ester synthesized at optimal conditions were confirmed by gas chromatography-mass spectrometry(GC-MS) and infrared spectrometry(IR) analysis.