【作者】 侯东丽；

【导师】 张正茂； 师俊玲；

【作者基本信息】 西北农林科技大学 ， 粮食油脂及植物蛋白工程， 2011， 硕士

【摘要】 谷氨酰胺转胺酶(TGase,简称TG)是一种催化酰基转移反应的转移酶,作为一种新型、安全的酶制剂,在国外已经历了十几年的研究,进行了大量的试验并逐渐应用于面粉制品生产中,而国内这方面的研究较少。目前,国内外对谷氨酰转胺酶在面制品中的应用研究主要集中在制粉和面制品加工两方面:在小麦制粉的润麦、混合等工序中使用TG可改善面粉品质,延长保质期,降低面粉致敏性;在焙烤食品如面包、曲奇饼、蛋糕等加工中使用,可改善食品品质。因此,利用TG的共价交联化学特性对面粉品质进行改善,在面粉制品的加工中具有重大的意义。本文针对TG对蛋白质的交联催化反应,主要研究了TG对小麦蛋白质和淀粉颗粒组分内及组分间的催化机理,以及TG对小麦面团结构特性的影响。为面粉加工品的发展奠定了理论基础。主要获得了以下结论:(1)采用组分分离方法,获得了小麦清蛋白、球蛋白、醇溶蛋白和麦谷蛋白等各个蛋白组分和淀粉颗粒,通过电子显微镜观察、可溶性蛋白含量的检测以及SDS-PAGE电泳分析,研究了TG对这些蛋白质的单一组分、两种蛋白组分、三种蛋白组分和四种蛋白组分内部及相互间作用的影响,重点考察了作用过程中可溶性蛋白含量和蛋白质电泳条带的变化;用扫描电子显微镜观察了酶作用条件下,每种单蛋白组分、两种蛋白组分、三种蛋白组分及四种蛋白组分与淀粉颗粒表面之间作用的影响。结果发现,TG可以催化小麦中清蛋白、球蛋白和醇溶蛋白组分的分子内和分子间的作用;对球蛋白的催化作用大于清蛋白,但两者均小于醇溶蛋白;清蛋白对TG催化其它蛋白组分的分子内结合有促进作用;球蛋白对TG催化醇溶蛋白分子内结合都有一定的抑制作用。(2)试验以小麦面团加酶前后,从面团的微观结构、蛋白质组分变化等方面研究了TG对小麦中蛋白组分间结合作用的影响。结果发现:TG可以增强小麦面团中面筋结构的强度;催化小麦清蛋白和球蛋白的相互作用;对小麦球蛋白的催化作用大于小麦清蛋白。更多还原

【Abstract】 Transglutaminase(TG) as a new, safe enzyme, which has been researched about ten years in foreign country. A series of tests had been carried out and it has gradually applied to the production of flour products, but there is less research about this area in domestic. The present researches of Transglutaminase focused on the two aspects of milling and pasta processing : the use of TG can improve flour quality, extend shelf life and reduce the allergenicity of wheat flour in the processes of tempering and mixing wheat flour, it can also rebound wheat quality when TG was used to hand Worm-eaten wheat and improve food quality of baked goods such as bread, cookies, cakes and so on. Therefore, the use of covalent crosslinking properties of Transglutaminase can improve the flour quality, which has a great significance and foreground in the processing of flour products.In this paper, the catalytic mechanism of TG in and between the components of wheat protein and starch granules was researched, meanwhile, the effort of group structure of wheat and buckwheat noodles was discussed, all above have laid a theoretical foundation for the development of flour processing.Through this research, the main conclusions were as following:(1)Based on the method of components separation,wheat albumin, globulin, gliadin, glutenin and starch granules were obtained, the effect of transglutaminase on the intra- and interaction of these isolated compounds was studied in the paper. The reaction was studied at the levels of single, two, three and four kinds of protein compounds and starch granules. Before and after the enzymatic reaction, content and molecular weight were analyzed according to the soluble protein content and SDS-PAGE analysis, and microstructure of the starch granules was also observed by using EMS. The results showed that TG could catalyze the interactions inner a same protein or between the different proteins including albumin, globulin, and gliadin. The effect of TG was greater on globulin than on albumin, and the greatest on gliadin among the three proteins. Albumin showed a negative effect on TG catalyzing the interaction of globulin and gliadin, while globulin showed a negative effect on gliadin.(2)Meanwhile, The Soba and the mixture of buckwheat flour and wheat were used as the control group to research the effect of transglutaminase (TGase) on the interaction among the buckwheat and wheat protein compounds in the aspects of microstructure, soluble protein content, and protein compounds. Results showed that TG strengthened the structure of gluten net in dough of wheat, buckwheat and mixture of the both. TG also could catalyze the interaction of albumin and globulin of wheat and buckwheat. As to buckwheat, the effect of TG was greater on albumin than on globulin, however, for wheat, it was reverse. TG showed greater effect on the mixture of buckwheat albumin and globulin than wheat albumin and globulin.更多还原