热加工条件对牛血清白蛋白-葡萄糖糖基化体系抗氧化活性的影响

Effect of Heat Processing Conditions on the Antioxidant Activity of Bovine Serum Albumin-Glucose Glycosylation System

为了得到具备优良抗氧化活性的糖基化产物,建立牛血清白蛋白(bovine serum albumin,BSA)-葡萄糖糖基化反应模型,以可溶性蛋白、自由氨基质量浓度为指标,考察不同反应时间和反应温度下体系的糖基化反应程度;并以1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸(2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS)阳离子自由基清除能力和还原能力为指标,评估上述条件对糖基化反应产物的体外抗氧化活性影响。结果表明:延长反应时间和升高反应温度均可提高糖基化反应程度,随着糖基化反应程度增加,BSA-葡萄糖体系中糖基化产物的抗氧化能力也随之增强,但反应程度过高,其抗氧化能力反而下降。反应温度为55℃时,反应48 h制备的糖基化体系具有最强的DPPH自由基清除能力、ABTS阳离子自由基清除能力和还原能力,其DPPH自由基清除能力、ABTS阳离子自由基清除能力半数清除率(half maximal inhibitory concentration,IC50)及还原能力(以光密度值为0.5时所需样品质量浓度ρ(OD0.5)计)分别为1.17、0.92 mg/mL和3.25 mg/mL;反应温度为80℃时,反应12 h制备的糖基化体系具有较强的DPPH自由基清除能力、ABTS阳离子自由基清除能力和还原能力,其DPPH自由基清除能力、ABTS阳离子自由基清除能力IC50及还原能力ρ(OD0.5)分别为1.02、0.68 mg/mL和3.62 mg/mL。综上,本实验可为控制食品热加工过程中抗氧化物质的形成提供数据参考。

In order to obtain glycosylation products with excellent antioxidant activity,a bovine serum albumin(BSA)-glucose glycosylation model was established.The contents of soluble protein and free amino groups were used as indicators of the glycosylation degree of the system at different reaction times and temperatures.The 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging capacity,2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)cation radical scavenging capacity and reducing power assays were applied to investigate the in vitro antioxidant activity of glycosylation products.The results showed that prolonging the reaction time and improving the reaction temperature could increase the glycation degree.With increasing glycation degree,the antioxidant capacity of BSA-glucose system first increased and then decreased.The product obtained after reaction at 55℃for 48 h had the strongest DPPH and ABTS cation radical scavenging capacity with half maximal inhibitory concentration(IC50)of 1.17 and 0.92 mg/m L,respectively,and the strong reducing power with a concentration required for optical density of 0.5(ρ(OD0.5))of and 3.25 mg/m L.In contrast,the product obtained after 12 h reaction 80℃exhibited IC50 of 1.02 and 0.68 for DPPH and ABTS cation radical scavenging,respectively andρ(OD0.5)of 3.62 mg/m L.Therefore,this study can provide useful data for controlling the formation of antioxidants in thermal food processing.