绿豆分离蛋白-葡聚糖接枝反应及产物抗氧化性研究  

Research on Grafting Reaction of Mung Bean Protein Isolate-Dextran and Antioxidant Activity of Conjugates

作　　者：齐宝坤[1] 赵城彬[2] 杨树昌 谭兆伦 李杨[1] Qi Baokun;Zhao Chengbin;Yang Shuchang;Tan Zhaolun;Li Yang(College of Food Science,Northeast Agricultural University,Harbin 150030;College of Food Science and Engineering,Jilin Agricultural University,Changchun 130118)

机构地区：[1]东北农业大学食品学院,哈尔滨150030 [2]吉林农业大学食品科学与工程学院,长春130118

出　　处：《中国食品学报》2018年第12期74-80,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：黑龙江省高等学校青年创新人才项目(UNPYSCT-2017010)

摘　　要：采用湿热法将绿豆分离蛋白(MBPI)与葡聚糖(DX)进行接枝反应,并对MBPI-DX接枝物的结构及抗氧化性进行研究。随着反应时间的延长,MBPI-DX接枝物的接枝度和褐变强度逐渐增加。MBPI的各亚基均能参与接枝反应,且小分子亚基最先参与反应。MBPI与DX接枝反应会降低蛋白质的荧光强度,同时使最大吸收波长发生不同程度红移,表明MBPI三级结构变得松散。随着反应时间的延长,MBPI-DX接枝物的表面疏水性逐渐降低,游离巯基含量呈先升高后下降的趋势,而整体上接枝反应会降低MBPI的游离巯基含量,这主要是因为热处理过程中蛋白质的巯基被氧化成二硫键造成的。接枝反应改善MBPI的抗氧化性,随着反应时间的延长,MBPI-DX接枝物的O2-·清除能力和还原力呈先增加后降低的趋势。Glycation reaction was occurred between mung bean protein isolate(MBPI) and dextran(DX) by wet heat processing. The structure and antioxidant activity of MBPI-DX conjugates were researched. The degree of graft and browning intensity of MBPI-DX conjugates increased gradually with the increase of reaction time. All the subunits of MBPI could participate in grafting reaction, and small molecule subunits were prior to participate in the reaction. Grafting reaction between MBPI and DX could reduce the fluorescence intensity of protein, and the maximum absorption wavelength appeared bathochromic shift in different degree, which indicated that the tertiary structure of MBPI became looser.As the increase of reaction time, the surface hydrophobicity decreased gradually, free sulfhydryl content showed a downward trend after the first rise. However, overall grafting reaction was able to reduce free sulfhydryl content of MBPI,which was mainly due to the oxidation of sulfhydryl to disulfide bond during the heat treatment. The antioxidant activity of MBPI could be improved by grafting reaction. Superoxide anion radical scavenging capacity and reducing power of MBPI-DX conjugates showed a downward trend after the first rise with the increase of reaction time.

关 键 词：绿豆分离蛋白 葡聚糖 接枝反应 抗氧化性 

分 类 号：TS201.21[轻工技术与工程—食品科学]