【作者】 黄琴；

【导师】 陈茂彬； 姚晓玲；

【作者基本信息】 湖北工业大学 ， 发酵工程， 2006， 硕士

【摘要】 植物甾醇是一种新型的降低血清胆固醇的功能活性成分。为了拓宽植物甾醇的应用范围,本论文对植物甾醇酯的制备工艺、生物活性及应用进行了研究。实验主要包括四个部分的内容:1)研究了植物甾醇的气相色谱定量分析方法:采用HP-5号石英毛细管气相色谱柱(30m×0.25mm×0.25μm),FID检测器;角鲨烷为内标;柱温285℃,进样器温度300℃。2)研究了化学方法合成甾醇乙酸酯(PSA)、甾醇油酸酯(PSO)、甾醇硬脂酸酯(PSS)和β—谷甾醇烟酸酯(PSN)四种甾醇酯的最佳合成工艺,重结晶精制工艺。采用气相色谱、红外光谱和质谱等方法对产品进行了定性分析。研究了植物甾醇和植物甾醇酯在大豆色拉油中的溶解度。初步研究了三种脂肪酶作生物催化剂在有机溶剂中对月桂酸甾醇酯的催化效果:最终选定Novo435脂肪酶为催化剂,正己烷为溶剂,反应温度40℃,酶用量为底物质量的15%,底物摩尔配比为3:1(月桂酸:甾醇),反应时间为24小时,酯化率达到36.5%。3)研究了PSA、PSO、PSS对高脂血症小鼠的治疗作用:与模型组相比,三种甾醇酯可不同程度地降低高脂血症小鼠的血清总胆固醇(TC)、低密度脂蛋白(LDL-C)、动脉硬化指标(AI),降低高血脂小鼠的肝重、肝脏TC和TG。其中,PSA与PSO对小鼠高脂血症的治疗效果比较理想,且明显好于PSS。4)研究了PSO的免疫调节作用:与S180荷瘤小鼠模型组比较,PSO能显著增加荷瘤小鼠巨噬细胞吞噬率和吞噬指数,效果优于环磷酰胺(Cy)药物对照组;PSO对迟发型超敏反应强度的作用明显,但效果不如Cy组;PSO虽能提高荷瘤小鼠的脾细胞抗体生成能力,但未达显著水平(p>0.05);PSO对荷瘤小鼠的血清溶血素含量影响不明显(p>0.05)。实验结果表明,PSO具有一定的免疫调节作用。5)研究了含植物甾醇乙酸酯酸奶的制作工艺:乳酸杆菌和嗜热链球以1:1的配比制作发酵剂,接种量为3%,加糖量为5%,甾醇乙酸酯添加量为0.65 g(每200 ml奶中),在43℃条件下发酵5 h,然后在0~5℃后熟24h制得。更多还原

【Abstract】 Phytosterol was used as a novel functional food ingredient with plasma cholesterol lowering activities for years. In order to improve solubility of free phytosterols in edible fats/oils, preparation technology, bioactivities and applications of phytosterols ester were studied systematically in this dissertation. It included four parts:1) GC method for the quantitative of phytosterols was developed: HP-5 capillary gas-chromatography column; FID detector; injector 300℃; oven temperature 285℃; squalane as internal standard.2) Four kinds of phytosterols esters involving phytosterols acetate(PSA)phytosterols oletate(PSO)、phytosterols stearic(PSS)andβ-Sitostanol nicotinate(PSN) was synthesized by chemosynthesis. The recrystallization method and optimal synthetic conditions of four phytosterols esters were studied. GC, IR and MS were used to determine the configuration of phytosterols esters. The solubility of phytosterols ester and phytosterols in soy salad oil were studied as well .Compared the catalysis of three lipases as biocatalyst to phytosterol laurate in a solvent-free system for pilot study: the Novo435 lipase was selected as biocatalyst, the optimal reaction conditions were confirmed to be 40℃, mole ratio of substrates 1:1,enzyme ratio over total weight 15%, reaction time 24h, and the yield of esterification was 36.5% in hexane.3) On therapeutic effect: compared with the hyperlipidemic model group, phytosterol esters could significantly reduce the serum TC, LDL-C and AI, lower the liver weight , TC and TG. There were different active effects among three phytosterol esters, PSA and PSO had ideal treatment effects on hyperlipidemia in mice and better than PSS.4) To evaluate the effects of PSO on the immune function : compared with the S18O-bearing mice model group,PSO could enhance significantly the phagocytosing ratio and the phagocytosing index(P<0.05 or P<0.01),the effects of PSO were better than Cyclophosphamide ; PSO also could improve evidently delayed—type hypersensitivity(P<0.05 or P<0.01),but worse than Cyclophosphamide;PSO could increase formation of antibody in splenic cells of S180-bearing mice,but there is not remarkable different(P>0.05);PSO had little influence on the contents of serum hemolysin(P>0.05). The results show that PSO could improve immunologic function of mice.5) Investigated the fermentation yogurt production technology of phytosterols acetate. The zymogen was fermented by Streptococcus thermophilus and Lactobacillus bulgaricus to 1:1;inoculation dosage was 3%; the amout of sugar was 5%, the amout of phytosterols acetate was 0.65 (every 200ml yogurt ); the zymolysis time was 5hr in 43℃. It was best to be cold stored at 0~5℃after fermentation and using post-acidification 24 h.更多还原