【作者】 徐清萍；

【导师】 陶文沂；

【作者基本信息】 江南大学 ， 发酵工程， 2005， 博士

【摘要】 生活方式、饮食习惯与现代流行病肥胖、心血管疾病、癌症等密切相关。健康意识的提高使消费结构有了新的变化,健康食品需求增加。科技的发展使医学模式发生很大变化,从传统单纯的治病的医学模式逐步转变为预防、治疗、康复相结合。自由基医学基础研究表明氧自由基引起的疾病已超过百种,而食品中存在着多种抗氧化成分,并在体内也有发挥抗氧化作用的可能性,可用于抑制生物体的氧化性损害。酿造食醋含有丰富的营养成分,具有独特的药理作用,至今已有两千多年历史。现代食醋功能研究表明食醋具有抗疲劳、调节血糖、调节血脂、降血压、抗氧化、抗癌、促进食欲、预防骨质疏松等多种生理功能。现代对食醋功能性研究主要集中于日本,食醋功能性成分研究多集中于其主要成分醋酸的生理活性研究,对其它活性成分及作用机理尚未有全面系统的研究。在我国历代医学著作中都有不少食醋参与的组方,镇江香醋是我国的知名品牌,对其抗氧化性研究有助于了解食醋的保健机理,开发出具有预防心血管、延缓衰老等疾病的抗氧化性产品,具有重要的社会意义和广阔的市场前景。本论文在系统研究食醋功能的相关研究文献和现代自由基医学的有关氧化损伤与疾病关系的理论和实验基础上,以自由基医学理论为指导,应用现代生物技术研究了食醋不同极性、不同分子量分离组分的抗氧化活性,确定较高自由基清除活性组分;对食醋不同组分的体外抗氧化活性进行综合评价;对食醋的体内抗氧化性进行研究;并对食醋中抗氧化性成分的来源、不同品种食醋抗氧化性差异进行了探讨。本论文首先研究了镇江香醋不同极性部位对DPPH自由基的清除活性,结果镇江香醋及其各极性部位可不同程度地清除自由基,镇江香醋自由基清除活性部位不同于日本黑醋。与日本黑醋相比,镇江香醋乙酸乙酯萃取物具有弱自由基清除活性。初步化学定性试验表明镇江香醋中含有有机酸、酚类、黄酮类、氨基酸。乙醇沉淀上清液浓缩物经无水丙酮、无水乙醇处理后分离得到的镇江香醋提取物V4,乙醇沉淀物中的水溶性成分V5,具有较高自由基清除活性。V4和V5在终浓度为150μg/mL时的清除率分别达到了56.31%、59.42%,在250μg/mL时的清除率均达到71.44%。V4在醋中的得率远高于V5,分别为71.33 g/L和16.05 g/L。在此基础上对镇江香醋提取物V4不同分子量组分在体外不同体系中的抗氧化性进行研究。研究表明镇江香醋提取物各分子量组分除低分子量组分F4外,均具有一定的还原性、具有清除羟自由基、清除超氧阴离子自由基、抑制亚油酸氧化、抑制人低密度脂蛋白氧化的作用。镇江香醋提取物总酚含量与DPPH自由基清除活性、还原力、抗亚油酸氧化存在正相关性。镇江香醋提取物较高DPPH自由基清除活性组分为低分子量组分F4,其次为高分子量组分F1。镇江香醋提取物高分子量组分中活性物质确定为美拉更多还原

【Abstract】 Modern epidemics such as adiposis, cardio-vascular diseases, cancer correlated nearly tolife style and dietetic habits. Demands for healthy food increased due to awareness of healthand the change of consume style. Simple medical treatment mode changed to the combinationof prevention, therapy and healing due to the development of science and technology. Fundamental study in free radical iatrology showed that oxygen radicals relate to hundredsof diseases. Antioxidants in food may be useful in vivo and can be used to prevent oxidationimpair. Brewed vinegar, characterized by its affluent nutriments and special pharmacologicalfunction, has a history of more than two thousands years. Vinegar has physiological effects,such as: promoting recovery from exhaustion, regulating blood glucose, blood pressure,antioxidant activity, anticancer, aiding digestion, stimulating the appetite, and promotingcalcium absorption. Related references centralized in Japan and the focus was the bioactivityof acetic acid which is one of the main components in vinegar. Systematical study on otheractive compounds and function mechanism hasn’t been made. Vinegar uses have beenmentioned in past-dynasties medical literatures, however, few study about vinegar’sphysiological function was undertaken in these days. Zhenjiang aromatic vinegar is one of themost famous traditional vinegar in China. Study on the antioxidant activity of vinegar will behelpful for better understanding of the health protection mechanism,be favor to theexploitation of new products that can prevent cardio-vascular diseases and retardingsenescence. The study has great social significance and wide market foreground. This thesis systematically studied antioxidant activity of the different polar, differentmolecular fractions of vinegar and confirmed the more effective fractions. At the same time,this thesis also determined the in vitro and in vivo antioxidant activity of different fractions,discussed the source of antioxidants in vinegar and compared the antioxidant activitydifference of different kinds of vinegars. The experiment studied DPPH radical scavenging activities of different polar extracts invinegar, the results indicate that different polar extracts have DPPH scavenging activities at adifferent extent. Zhenjiang aromatic vinegar has weak radical scavenging activities comparedwith Kurosu. Organic acid, phenolic compounds, flavones and amino acid in vinegar wereconfirmed by chemical qualitative analysis. Zhenjiang aromatic vinegar extract (V4), obtainedby dealing concentrated ethanol supernate of vinegar with acetone and ethanol absolute, andsoluble fraction of Zhenjiang ethanol precipitation (V5) are more active components. PercentDPPH scavenging activities of V4 and V5 are 56.31% and 59.42%, respectively, at a finalconcentration 150 μg/mL. Percent DPPH scavenging activities for V4 and V5 both are71.44%. Yields of V4 are much higher than V5, 71.33 g/L and 16.05 g/L, respectively.On the base of former study, antioxidant activities of different fractions of V4 wereevaluated using different in vitro tests: the DPPH radical scavenging activity, the reducingpower, the amount of total phenolic compounds, the inhibitory effect on hydroxyl radical andsuperoxide anion radical, the inhibitory effect on oxidation of LDL. Zhenjiang aromaticvinegar extract (V4) and individual fractions, except F4, were found to have antioxidantactivities in all the model systems tested. Amounts of phenolic compounds have a positivecorrelation with DPPH radical scavenging activity, reducing power, inhibition of linoleic acidoxidation. DPPH scavenging activities of low molecular weight fraction (F4) is the highest,high molecular weight fractions (F1) the second. Active compounds in high molecular weightfractions of Zhenjiang aromatic vinegar are Maillard reaction products, melanoidins.Effect of concentrated Zhenjiang aromatic vinegar on oxidative modification of low densitylipoprotein (LDL) which was initiated by Cu2+ was studied. The results showed thatconcentrated Zhenjiang aromatic vinegar could inhibit the oxidative modification of LDL, andHV could block the oxidative reaction of the already oxidatively modified LDL.The senior model of Kunming-mice was built with D-galactose. Different doses of vinegarwere administered to the experimental mice. Liver index, spleen index and brain index weredetermined. MDA, SOD, GSH-Px of mice plasm, MDA and SOD of mice liver, brain weremeasured. The results indicated that HV could (1) effect greatly on liver index of mice(P<0.01), (2) increase the activities of SOD (P<0.05), GSH-Px/LPO ratio (P<0.01) andreduce the level of MDA in plasm, (3) reduce the level of MDA in liver (P<0.05).Changes of amount of total phenolic compounds, total flavones, and DPPH scavengingactivities during production were studied. The results indicated that (1)changes of amount oftotal phenolic compounds, total flavones have a positive relationship with percent DPPHscavenging activities, correlative coefficients were 0.9334 and 0.9353, respectively, (2)acetic acid fermentation period and decoction period have a higher influence on scavengingactivities. Storing time has a certain effect, short period of storing hasn’t a distinct effect, (3)phenolic compounds, flavones and Maillard reaction products ( MRPs ) were main DPPHscavenging activity compounds in Zhenjiang aromatic vinegar.Amount of total phenolic compounds, total flavones and DPPH scavenging activity fordifferent kinds of vinegars were compared. The results indicate that (1) DPPH scavengingactivity of different kinds of vinegars has a positive correlation with amount of total phenoliccompounds, total flavones, the correlation coefficients were 0.9523 and 0.8691, respectively,(2) the higher content of phenolic compounds and flavones in Zhenjiang aromatic vinegarrespond for its higher scavenging activity.This research also indicated that (1) amount of total phenolic compounds, total flavonesand percent of DPPH scavenging activity can be used as discriminate index for differentkinds of vinegars, (2) new antioxidant may be formed during acetic acid fermentation periodand decoction period, and be worth further researching.更多还原