多糖的共价键合对7S球蛋白凝胶性能的影响  

Effect of glycosylation on gel properties of β-conglycinin under macromolecular crowding condition

作　　者：翁静宜 齐军茹[1] 张曦[1] 康燕辉[1] 冯纪璐 杨晓泉[1] 朱建华[2] 

机构地区：[1]华南理工大学轻工与食品学院,广东广州510640 [2]韶关学院食品科学与工程学院,广东韶关512005

出　　处：《化工学报》2014年第12期5075-5081,共7页CIESC Journal

基　　金：国家自然科学基金青年面上连续资助项目(31370036);国家自然科学基金项目(31101215);广东省高等学校高层次人才项目(粤财教[2013]246号)~~

摘　　要：引入细胞学说中的大分子拥挤体系并在该体系通过Maillard反应制备了大豆7S球蛋白(β-conglycinin,7S)和葡聚糖(dextran,Dex)的共价复合物,利用转谷氨酰胺酶(transglutaminase,TGase)的交联作用制得蛋白-多糖共价复合物凝胶。对其流变学、质构特性及微结构进行分析。结果表明,在大分子拥挤环境下,7S-葡聚糖比例为2:1的共价复合物制得具有致密且孔洞分布均匀的凝胶网络结构。单纯的蛋白自聚集或者与多糖的共混状态时形成的凝胶弹性模量都较高,但蛋白过度的聚集并不能得到孔洞均匀的凝胶网络结构,共价复合物制备的凝胶中葡聚糖的共价键合作用抑制了TGase交联过程中蛋白质分子间发生过度的相互作用。形貌学观察表明,共价复合物制备的凝胶形成了网络孔径均匀且非常致密的凝胶网络结构。The effect of glycosylation on the aggregation behavior of β-conglycinin （7S） under the macromolecular crowding condition in the liquid system and the influence of covalent attachment of polysaccharide on gelation of β -conglycinin （7S） were investigated. The gel network of the conjugate became orderly and compact at 7S/dextran （mass ratio） of 2：1. First, β-conglycinin-dextran covalent conjugate was prepared via the Maillard reaction under macromolecular crowding condition. Sodium dodecyl sulfate- polyacrylamide gel electrophoresis （SDS-PAGE） was used to confirm the formation of covalent conjugate of 7S-dextran. Transglutaminase （TGase） was introduced for gelation to form a covalent network. Dynamic rheological analysis indicated that the addition of dextran increased the degree of crowding in the liquid system, promoting the formation of gel network. The presence of dextran with high concentration and the covalent attachment to ^-conglycinin led to phase separation and inhibited extensive protein-protein interactions during the process of TGase cross-linking. Moreover, frequency sweep measurements revealed that the strength of the gel prepared by conjugation was reduced with increasing concentration of dextran. Scanning electron microscopy observation indicated that the network of gel began to transform to lamellar structure with increasing dextran concentration.

关 键 词：大豆7S球蛋白 葡聚糖 大分子拥挤体系 MAILLARD反应 凝胶特性 聚集 流变学 

分 类 号：TS201.7[轻工技术与工程—食品科学]