【作者】 潘艳；

【导师】 郑群雄；

【作者基本信息】 浙江工商大学 ， 食品科学， 2008， 硕士

【摘要】 食品热加工过程中会形成丙烯酰胺,该物质具有神经毒性、基因毒性等,对动物具有致癌性,其毒性的控制是目前国际上研究的热点。丙烯酰胺本身是低毒的,当丙烯酰胺进入机体后经细胞色素P450 2E1催化氧化为环氧丙酰胺,后者才是对机体产生危害的根源。加入外源性抗氧化剂（如维生素C、蛋氨酸、大蒜素等）可有效抑制丙烯酰胺的环氧化,降低环氧丙酰胺的形成,达到控制丙烯酰胺毒性的目的。本文以抑制丙烯酰胺的环氧化和降低其吸收为切入点,对丙烯酰胺毒性控制作一些基础性的探索。1.食品中美拉德反应生成丙烯酰胺的同时还会形成一些具有抗氧化活性的物质。本论文为了研究由美拉德反应生成的抗氧化物质的抗氧化能力与由同一反应形成的丙烯酰胺的浓度之间的关系,通过模拟食品中葡萄糖和天门冬酰胺美拉德反应,探寻丙烯酰胺生成量和美拉德反应产物抗氧化活性间关系。利用反相高效液相色谱（RP-HPLC）检测丙烯酰胺的浓度,以DPPH清除率、还原能力和羟基自由基清除率表征产物的抗氧化活性,研究了pH值、温度、时间、葡萄糖和天门冬酰胺体积比、氨基酸和糖对美拉德反应的影响。结果表明,食品热加工过程中既会生成丙烯酰胺又可以生成具有抗氧化活性的物质,且随着丙烯酰胺生成量的增加,美拉德反应产物抗氧化活性也增强（在120℃和180℃之间,丙烯酰胺生成量和产物羟基清除率在一定程度上呈线性关系）,这些抗氧化物质有可能作为食品内源性抗氧化剂参与抑制丙烯酰胺的环氧化,降低环氧丙酰胺的生成,从而控制丙烯酰胺的毒性。2.模拟体外丙烯酰胺和谷胱甘肽反应,其产物可经尿液直接排出体外,降低了丙烯酰胺的吸收,减少被氧化的丙烯酰胺浓度。通过降低丙烯酰胺吸收的方法,为进一步控制丙烯酰胺毒性提供新的思路。建立了谷胱甘肽巯基反相高效液相色谱检测方法,通过巯基变化测得丙烯酰胺和谷胱甘肽一次反应速率和二次反应速率分别为0.0491 min^-1和0.0001 mM^-1min^-1。结果表明,丙烯酰胺与谷胱甘肽反应后可以降低游离丙烯酰胺的含量,有可能在一定程度上起到降低丙烯酰胺毒性的作用。更多还原

【Abstract】 Acrylamide produced in heat-processed foods had been known to be neurotoxic,genotoxic and carcinogenic in animals.Presently, investigation of inhibiting acrylamide-induced toxicity had triggered worldwide concern.It was well known that acrylamide converted into glycidamide was catalyzed from P450 2E1 in vivo,which played an important role in toxicity effects.Exogenous antioxidant can inhibit acrylamide toxicity bycontrolling epoxidation to decrease the process of its conversion into glycidamide such as Vitamine C,Methionine,Allicin, etc.There was a preliminary study on reducing acrylamide toxicity by controlling epoxidation and elimination of acrylamide.1.Maillard reaction in foods produced acrylamide and other products which exhibited antioxidant activity.The aim of this study was to estimate the correlation of acrylamide with antioxidant activity of Maillard reaction products（MRPs）by a glucose-asparagine model.Acrylamide in reaction solutions was determined by reversed phase high performance liquid chromatography（RP-HPLC）.Antioxidant activity was characterized by 1,1-dipheny-2-picrylhydrazyl（DPPH）, reducing power and hydroxyl radical scavenging activity.Factors including pH,temperature,reaction time,the volume ratio of glucose-to-asparagines,the sorts of amino acid as well as sugar affecting the acrylamide formation were tested with glucose-asparagines as a model.By the way,products from Maillard reaction exhibited antioxidant activity.The result in this paper showed the more concentration of acrylamide,the higher antioxidant activity of MRPs（hydroxyl radical scavenging activity presented good correlation with acrylamide treated between 120℃and 180℃）.Antioxidant activity of MRPs may inhibit acrylamide toxicity by preventing the process of epoxidation from P450 2E1 to decrease glycidamide.2.Acrylamide-glutathione reaction simulated in vitro was investigated.The reaction products were directly excreted in urine,which decreased the absorption of acrylamide not to be converted into glycidamide.Reducing of acrylamide absorption will provide a new way for controlling acrylamide toxicity.A RP-HPLC method was developed for determination of glutathione sulfhydryl to observe the acrylamide-glutathione reaction and pseudo-first-order rate constants and second-order rate constants of acrylamide with glutathione were 0.0491 min^-1and 0.0001 mM^-1min^-1 respectively.It was showed that the process of reaction will decrease the concentration of acrylamide for controlling acrylamide toxicity.更多还原