【作者】 刘欢；

【导师】 黄师荣；

【作者基本信息】 湘潭大学 ， 化学工程与技术， 2022， 硕士

【摘要】 腌榨菜叶含有丰富的多酚、黄酮、花青素和单宁等酚类物质,可以有效预防糖尿病、肥胖症、高血压等疾病。而酚类物质能否在人体内充分释放并实现其各种功能与其在人体内的消化、吸收和代谢状况有着密切联系,因此,评估酚类物质消化后的变化尤为重要。本文以腌榨菜叶为原料,通过体外模拟消化的方式,研究消化后腌榨菜叶及其乙醇提取物酚类物质成分含量、抗氧化活性和代谢综合征相关酶活性变化,植物油对酚类物质的保护作用以及不同消化方法对腌榨菜叶抗氧化性能的影响。主要研究内容及结论如下:(1)研究了体外模拟消化对腌榨菜叶(PM)及其乙醇提取物(PM-E)酚类物质和抗氧化活性的影响。结果表明PM和PM-E经消化后总酚、黄酮、花青素和单宁含量均显著增加,2,2’-偶氮-双(3-乙基苯并噻唑-6-磺酸)二铵盐(ABTS)、2,2-联苯基-1-苦基肼基(DPPH)自由基清除能力和铁离子还原能力(FRAP)提高,抗氧化能力增强,且PM>PM-E。关联性分析表明总酚、黄酮、花青素和单宁含量是影响PM和PM-E抗氧化活性的主要原因。通过液质联用分析,共鉴定出包括邻香豆酸、对香豆酸、对羟基苯甲酸、阿魏酸、4-羟基肉桂醛、没食子酸、槲皮素、山奈酚和异鼠李素等9种酚类化合物,经消化后邻香豆酸、对羟基苯甲酸和没食子酸的含量显著增加。(2)研究了腌榨菜叶及其乙醇提取物经体外模拟消化后不同形态酚类化合物的抗氧化活性变化。结果表明,PM和PM-E消化后游离酚总酚、黄酮含量显著增加,ABTS、DPPH自由基清除能力和FRAP提高,抗氧化活性增强。而共轭酚和结合酚总酚、黄酮含量、ABTS、DPPH自由基清除能力和FRAP总体呈上升趋势,抗氧化活性增强。关联性分析表明总酚和黄酮含量是影响PM和PM-E消化后不同形态酚类化合物抗氧化活性变化的主要原因。(3)研究了腌榨菜叶及其乙醇提取物经体外模拟消化后对代谢综合征相关酶活性的影响。结果表明,PM和PM-E消化后总酚和黄酮的生物可及性提高,对于未消化样品,PM和PM-E都可以抑制α-淀粉酶和α-葡萄糖苷酶活性,且PM-E>PM,经消化后对α-淀粉酶和α-葡萄糖苷酶抑制作用明显提高。PM和PM-E消化前后对脂肪酶均无抑制作用。关联性分析表明,总酚、黄酮和单宁是影响PM和PM-E消化后对α-淀粉酶、α-葡萄糖苷酶抑制作用的关键因素。(4)研究了腌榨菜叶与植物油(O)的组合,以评价植物油对体外消化条件下酚类化合物的保护作用。结果表明,PM+5%O和PM+10%O消化后总酚、黄酮、花青素和单宁含量均显著增加,抗氧化活性增强。与PM消化后相比,添加植物油样品消化后的总酚、花青素和单宁含量更高,抗氧化能力提高,且随着植物油含量的增加,抗氧化能力更强。(5)研究了腌榨菜叶经五种不同体外模拟方法(D1-D5)消化后的抗氧化活性变化。结果表明,PM-D1消化后总酚、黄酮、花青素和单宁含量增加,抗氧化活性增强;PM-D2消化后总酚、黄酮和单宁含量增加,抗氧化活性增强;PM-D3消化后总酚、黄酮和单宁含量增加,抗氧化活性降低;PM-D4消化后总酚、黄酮和花青素含量降低,单宁含量无明显差异,抗氧化活性降低;PM-D5消化后总酚和单宁含量增加,黄酮和花青素含量降低,ABTS自由基清除能力降低,DPPH自由基清除能力增强,FRAP无明显差异,抗氧化活性不明显。更多还原

【Abstract】 Pickled mustard is rich in polyphenols,flavonoids,anthocyanins,tannins,which can effectively prevent diabetes,obesity,hypertension and other diseases.Whether phenolics can be fully released in the human body and realize their various functions is closely related to their digestion,absorption and metabolism.Therefore,it is particularly important to evaluate the changes of phenolics after digestion.In this study,pickled mustard leaves were used as raw materials to study the changes of phenolic components,antioxidant activities and the activities of enzyme related to metabolic syndrome of pickled mustard leaves and its ethanol extracts after digestion,the protective effects of vegetable oil on phenolic substances,and the effects of different digestion methods on antioxidant performance were studied by simulated digestion in vitro.The main research contents and conclusions were shown as follows:(1)The effects of simulated digestion in vitro on the phenolic compounds and antioxidant activities of pickled mustard leaves(PM)and its ethanol extracts(PM-E)were studied.The results showed that the contents of total phenol,flavonoids,anthocyanins and tannins were significantly increased in PM and PM-E after in vitro digestion,2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt(ABTS),2,2-diphenyl-1-picrylhydrazyl(DPPH)free radical scavenging ability and iron reducing ability(FRAP)were increased,the antioxidant ability was enhanced,and PM>PM-E.The correlation analysis showed that total phenol,flavonoids,anthocyanins and tannins were the key factors affecting the change of the antioxidant activities of PM and PM-E.HPLC-MS analysis showed that nine phenolic compounds including o-coumaric acid,p-coumaric acid,p-hydroxybenzoic acid,ferulic acid,4-hydroxyl cinnamaldehyde,gallic acid,quercetin,kaempferol and isorhamnetin were identified.After in vitro digestion,the contents of o-coumaric acid,p-hydroxybenzoic acid and gallic acid were significantly increased.(2)The effects of simulated digestion in vitro on the antioxidant activities of phenolic compounds in different forms from pickled mustard leaves and its ethanol extracts were studied.The results showed that the contents of total phenol and flavonoids were significantly increased in free phenolics from PM and PM-E after digestion,ABTS,DPPH radical scavenging ability and FRAP were increased,and the antioxidant activity was enhanced.The contents of total phenol and flavonoids,ABTS,DPPH free radical scavenging ability and FRAP were overall upward trend in conjugated and bound phenolics after digestion,and the antioxidant capacity was enhanced.The correlation analysis showed that the contents of total phenol and flavonoids were the main factors affecting the change of the antioxidant activities of phenolic compounds in different forms from PM and PM-E after digestion in vitro.(3)The effects of simulated digestion in vitro on the activity of enzymes related to the metabolic syndrome of pickled mustard leaves and its ethanol extracts were studied.The results showed that the bioaccessibility of total phenol and flavonoids increased in PM and PM-E after digestion.The undigested samples of PM and PM-E inhibited α-amylase and α-glucosidase,PM-E>PM,the inhibitory effect of digested samples on α-amylase and α-glucosidase was significantly enhanced.PM and PM-E had no inhibitory effect on lipase before and after digestion.The correlation analysis showed that total phenol,flavonoids and tannin were the key factors affecting the inhibition of PM and PM-E on α-amylase and α-glucosidase.(4)The combination of pickled mustard leaves with vegetable oil(O)were studied in order to evaluate the protection of vegetable oil on the phenolic compounds submitted to in vitro digestion conditions.The results showed that the contents of total phenol,flavonoids,anthocyanins and tannins were significantly increased in PM+5%O and PM+10%O after digestion,and the antioxidant activity was enhanced.Compared with PM,the contents of total phenol,anthocyanins and tannins were higher after adding vegetable oil,the antioxidant capacity was enhanced.The antioxidant capacity was stronger with the increase of vegetable oil.(5)The effects of five different simulated digestion in vitro methods(D1-D5)on the antioxidant activities of pickled mustard leaves were studied.The results showed that the contents of total phenol,flavonoids,anthocyanins and tannins were increased in PM-D1 after digestion,and the antioxidant ability was enhanced.The contents of total phenol,flavonoids and tannins were increased in PM-D2,and the antioxidant ability was enhanced.The contents of total phenol,flavonoids and tannins were increased in PM-D3,and the antioxidant ability was decreased.The contents of total phenol,flavonoids and anthocyanins were decreased in PM-D4,the content of tannin had no significant difference,and the antioxidant activity was decreased.The contents of total phenol and tannins were increased in PM-D5,and the contents of flavonoids and anthocyanins were decreased,ABTS free radical scavenging ability was decreased,DPPH free radical scavenging ability was increased,while FRAP showed no significant difference,and the antioxidant activity was not obvious.更多还原