【作者】 黄盟盟；

【导师】 周广田；

【作者基本信息】 山东轻工业学院 ， 发酵工程， 2010， 硕士

【摘要】 10-羟基-2-癸烯酸(10-HDA),是蜂王浆中一种重要的不饱和脂肪酸,占蜂王浆脂肪酸总量的50%左右,在蜂王浆中的含量为1.4%～2.0%。10-HDA能强烈地抑制细菌、真菌的生长,并具有杀死肿瘤细胞的作用。原浆小麦啤酒是不经过滤的小麦啤酒,其中含有一定数量的活酵母;但是其生物稳定性较差,主要是短乳杆菌和有害片球菌作用引起的。有资料表明,10-HDA对酵母菌无抑制作用,可以考虑作为啤酒中抑菌剂,改善啤酒的生物稳定性。本论文主要内容:1.在前人对10-HDA研究的基础上,将提取条件进行了优化,并分别用HPLC法和分光光度法测定提取液中10-HDA的含量。HPLC中以对羟基苯甲酸甲酯为内标物,甲醇+0.01mol/L HCl (55+45)为流动相。我们还分析了HPLC方法的重现性,回收率和精密度,结果表明HPLC方法的重现性较好,10-HDA在第4～5min开始出峰;平均回收率为100.3%,RSD为0.28%;精密度为99.9%,RSD为1.3%。2.测定了引起啤酒污染的短乳杆菌和有害片球菌的生长曲线,为我们以后的菌种培养工作提供了依据。采用扩散法证明了10-HDA对两种细菌均具有抑菌活性;用逐步稀释法测定了短乳杆菌和有害片球菌的的最低抑菌浓度(MIC)分别为:125μg/mL和500μg/mL;在啤酒中接入有害菌模拟污染啤酒,并加入10-HDA,并用流式细胞仪测定抑菌效果,发现加入10-HDA 2h后对两种细菌的致死率分别为92.98%和90.92%,而36h后致死率为95.66%和92.16%,最终确定了10-HDA在清酒罐中的添加量为最终浓度为500μg/mL。3.测定了加入10-HDA的原浆小麦啤酒的一系列的理化指标,结果均符合国家标准的要求,同时还应用NBB-B在27℃培养基检测其中的有害菌变色反应,啤酒在3天后变色,属于啤酒厂安全卫生生产要求的范围之内。还建立了啤酒品评的模糊矩阵法,是一种快速简单、直观、量化地鉴定啤酒的感官质量的方法,加入10-HDA原浆小麦啤酒评价为“优”和“良好”的隶属度分别为0.48和0.368。更多还原

【Abstract】 10-hydroxy-2-decenoic acid (10-HDA) is a significant unsaturated fatty acid in royal jelly.10-HDA content takes 50% of total fatty acid content and 1.4% to 2.0% of royal jelly. Prior studies indicated that 10-HDA showed obvious inhibition with microbe and fungi, it also play roles in killing tumor cell. Plasm wheat beer was a novel beer product, which contains a spot of viable yeast cells, whereas it has a brittle biological stability, derived from contamination of Lactobacillus brevis and Pediococcus damnosus. Some essay confirmed that 10-HDA did not has any inhibition on yeast metabolism, thus our purpose was applying 10-HDA to beer conservation and got a longer quality guarantee period under good biological stability.The main contents of this paper was under list:1. Extracting conditions were optimized on the basis of the predecessors′study of the 10-HDA extraction. The content of 10-HDA in extraction solution was determined with High Performance Liquid Chromatography method and spectrophotometry method, respectively. Methyl-p-hydroxybenzoate was served as internal standard substance in determination process of High Performance Liquid Chromatography mobile phase was a mixed solution of methanol to 0.01mol/L hydrochloric acid ratio of 55:45. Repeatability, recovery and precision of High Performance Liquid Chromatography were analyzed. 10-HDA chromatographic peak appeared ranges from 4 to 5 min and showed good repeatability. Average recovery rate was 100.3% has a RSD of 0.28%, precision was 99.9% has a RSD of 1.3%, respectively.2. Growth curve of Lactobacillus brevis and Pediococcus damnosus inoculated in MRS medium were described, give us a guidance of in their subsequent culturing. Bacteriostatic circle experiments, a diffusion method, was employed to certificated inhibition of 10-HDA to the two microbe. Minimum inhibitory concentration (MIC) of 10-HDA to Lactobacillus brevis and Pediococcus damnosus were 125μg/mL and 500μg/mL, respectively. The two strains were inoculated into plasm wheat beer, antimicrobial affect were determined after adding 10-HDA with a flow cytometry. Lethality of Lactobacillus brevis at the 2ed hour and 36th hour were 92.98% and 95.66%, respectively; Pediococcus damnosus was at 90.92% and 92.16%. The final dosage of 10-HDA in Bright Beer Tank was 500μg/mL.3. Physical and chemical index of plasm wheat beer, contains 10-HDA, was measured. The index was within the pale of national standards. The test solution turned into yellow at the 3rd day while deal with NBB-B medium under 27℃was safe. Fuzzy matrix comprehensive evaluation model in beer sensory analysis was constructed, is characterized by simple, quick, visual and quantized. Evaluation of beer belongs to excellent and good were 0.48 and 0.368, respectively.更多还原