D-氨基半乳糖改性对玉米谷蛋白结构性质及抗氧化活性的影响  

Effects of modification by D-galactosamine on structural properties and antioxidant activities of corn glutelin

作　　者：王晓杰[1,2] 曲悦 刘晓兰 丛万锁[1,2] WANG Xiao-jie;QU Yue;LIU Xiao-lan;CONG Wan-Suo(College of Food and Biological Engineering, Qiqihar University, Qiqihar, Heilongjiang 161006, China;Key Laboratory of Corn Deep Processing Theory and Technology, Qiqihar, Heilongjiang 161006, China)

机构地区：[1]齐齐哈尔大学食品与生物工程学院,黑龙江齐齐哈尔161006 [2]黑龙江省玉米深加工理论与技术重点实验室,黑龙江齐齐哈尔161006

出　　处：《食品与机械》2019年第7期176-180,共5页Food and Machinery

基　　金：黑龙江省省属高等学校基本科研业务费科研项目(粮头食尾)(编号：LTSW201739,LTSW201719);黑龙江省省属高等学校基本科研业务费青年创新人才科研项目(编号：135309345)齐齐哈尔市科学技术计划项目(编号：GYTG-201701)

摘　　要：为了提高玉米谷蛋白的水溶性,采用谷氨酰胺转氨酶(TGase)和D-氨基半乳糖对玉米谷蛋白进行糖基化改性,研究了糖基化改性对原玉米谷蛋白结构性质及抗氧化活性的影响。红外光谱的测定结果表明,在TGase的催化下,玉米谷蛋白与D-氨基半乳糖发生了共价结合。与玉米谷蛋白相比,D-氨基半乳糖的共价结合使玉米谷蛋白的游离氨基含量增加158mmol/kg·蛋白,热变性温度和变性焓分别降低9.03℃和68.74J/g,即糖基化改性使玉米谷蛋白的结构变得无序而松散,热稳定降低;同时,糖基化改性使玉米谷蛋白对3种自由基(包括DPPH、羟基和超氧阴离子)的清除活性、对Fe^2+的螯合能力以及还原力等显著提高,尤其是Fe^2+螯合活性,其EC50值减少了1.27mg/mL。试验结果表明酶法糖基化是一种适合于对玉米谷蛋白进行改性的有效方法。The transglutaminase (TGase) and D -galactosamine were modified improve the solubility in water of corn glutelin. The effect of the glycosylation modification on structural properties and antioxidant activities of original corn glutelin were evaluated. The result of Fourier transform infrared spectroscopy indicated that D -galactosamine was covalently conjugated to corn glutelin under the catalysis of transglutaminase. The free amino groups and the denaturation temperature, as well as the enthalpy of thermal denaturation of the glycosylated corn glutelin, decreased by 158 mmol/kg protein and 9.03 ℃ and 68.74 J/g compared with the original corn glutelin, respectively. These indicated that the structure of corn glutelin became disordered and loose, and the thermal stability of corn glutelin was significantly decreased by glycosylation modification. Meanwhile, three radical scavenging activities (including DPPH, superoxide, hydroxyl), Fe^2+-chelating capacity, and the reducing power of the glycosylated corn glutelin were increased, and its EC 50 value for Fe^2+-chelating capacity was decreased by 1.27 mg/mL. The results suggested that enzymatic glycosylation would be an effective method for the modification of corn gluten.

关 键 词：玉米谷蛋白 D-氨基半乳糖 糖基化 热稳定性 抗氧化活性 

分 类 号：TS201.2[轻工技术与工程—食品科学]