大豆糖蛋白的抗氧化特性  

Antioxidant Property of Soy Glycoprotein

作　　者：夏秀芳[1] 王博[1] 郑幸子 邓思杨[1] 潘男 王浩[1] XIA Xiufang;WANG Bo;ZHENG Xingzi;DENG Siyang;PAN Nan;WANG Hao(College of Food Science,Northeast Agricultural University,Harbin 150030,China)

机构地区：[1]东北农业大学食品学院,黑龙江哈尔滨150030

出　　处：《食品科学》2018年第7期91-97,共7页Food Science

基　　金：黑龙江应用技术研究与开发计划重大项目(GA15B302);黑龙江省博士后资助项目(LBH-15013)

摘　　要：大豆分离蛋白(soy protein isolate,SPI)与葡萄糖按质量比1∶1混合后通过美拉德反应生成大豆糖蛋白,通过测定不同反应温度(70、80、90℃)、反应时间(0、1、2、3、4、5、6 h)大豆糖蛋白的还原能力、羟自由基清除能力、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力、游离氨基含量、褐变程度、紫外光谱扫描分析和十二烷基硫酸钠-聚丙烯酰氨凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)等指标,探讨大豆糖蛋白的抗氧化性及其作用机理。结果表明:随着反应时间的延长、反应温度的升高,大豆糖蛋白的抗氧化性越高、游离氨基含量下降越多、反应褐变程度越大,90℃、6 h制得的大豆糖蛋白还原能力达到最高,比SPI还原能力高4.6倍;90℃、5 h的大豆糖蛋白羟自由基清除能力最高,为5.87%,是SPI羟自由基清除率的1.69倍;同时在90℃、5 h制得的大豆糖蛋白还具有最高的DPPH自由基清除率,比SPI提高了2.68倍。由大豆糖蛋白的紫外光谱二阶导数分析可知,经过美拉德反应后蛋白中色氨酸发生偏移,而从SDS-PAGE的分析中也看出蛋白质与糖发生聚合。因此,大豆蛋白葡萄糖反应生成的大豆糖蛋白具有很强的抗氧化性,并且抗氧化性与蛋白结构的变化密切相关。Soy glycoprotein was prepared from soy protein isolate(SPI)and glucose(m/m=1:1)by Maillard reaction at 70,80 or 90℃for 0,1,2,3,4,5,6 h respectively.The reducing power,and hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging capacity of products at different reaction times were determined.Moreover,browning degree,ultraviolet(UV)spectroscopic analysis,and sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)were studied to explore the antioxidant mechanism of soy glycoprotein.The results showed that the antioxidant effect and browning degree of soy glycoprotein was significantly increased,and free amino group content was remarkably increased with an increase in reaction temperature and time.It was proved that soy glycoprotein obtained after reaction for 6 h at 90℃had the maximum reducing power,which was 5.6 times higher than SPI.Soy glycoprotein obtained after reaction at 90℃for 5 h exhibited the highest hydroxyl radical scavenging(a 1.69-fold increase over SPI)and DPPH radical scavenging activity(scavenging activity of 68.55%,a 3.68-fold enhancement over SPI).Through analysis of the secondary derivative ultraviolet spectrum,tryptophan migration in the protein occurred during the Maillard reaction.Meanwhile,SDS-PAGE illustrated that SPI and glucose formed high molecular weight conjugates.All in all,these results suggest that soy glycoprotein has antioxidant properties,which has a close relationship with the changes of protein structure.

关 键 词：大豆蛋白 美拉德反应 糖蛋白 抗氧化 结构 机理 

分 类 号：TS201.2[轻工技术与工程—食品科学]