三相萃取黄参蛋白质及其抗氧化性分析

Three phase-partitioning extraction and antioxidant activity of protein from Sphallerocarpus gracilis

在单因素试验基础上,采用正交试验优化三相萃取(TPPE)蛋白质的条件,对黄参蛋白质(SGP)组分SGP-1和SGP-2的体外抗氧化性进行研究。结果表明,SGP的最优提取条件为硫酸铵饱和度50%,蛋白质提取液和叔丁醇体积比1.0∶1.0,萃取体系pH值4.5,萃取温度20℃,萃取时间15 min。在此优化条件下,平均蛋白质提取率为(88.71±0.54)%,显著高于硫酸铵沉淀法(76.49±0.70)%(P<0.05)。蛋白组分SGP-1和SGP-2对DPPH、ABTS+自由基最大清除率分别为(61.25±1.51)%、(51.20±1.40)%和(89.20±1.46)%、(89.10±1.39)%;蛋白组分SGP-1和SGP-2的铁离子还原能力(FRAP)值、氧自由基吸收能力(ORAC)指数分别为0.99 mmol/L、(109±1.56)μmol TE/mg和0.59 mmol/L、(65±1.42)μmol TE/mg。两个样品在一定质量浓度范围内抗氧化性均呈现浓度依赖性,与SGP-2相比,SGP-1具有较高的体外抗氧化活性。

On the basis of single factor experiments,the three phase-partitioning extraction(TPPE)technology of Sphallerocarpus gracilis protein(SGP)was optimized by orthogonal experiments,and the in vitro antioxidant activities of SGP components SGP-1 and SGP-2 were further studied.The results showed that the optimal extraction condition of SGP was ammonium sulfate saturation 50%,protein extract solution to tert-butanol ratio 1.0∶1.0,system pH 4.5,extraction temperature 20℃and time 15 min.Under the optimal condition,the average protein extraction rate was(88.71±0.54)%,which was significantly higher than that from ammonium sulfate precipitation(76.49±0.70)%(P<0.05).The maximum scavenging rates of protein components SGP-1 and SGP-2 on DPPH and ABTS+free radicals were(61.25±1.51)%,(51.20±1.40)%and(89.20±1.46)%,(89.10±1.39)%,respectively.The ferric reducing ability of plasma(FRAP)value and oxygen radical absorbance capacity(ORAC)index of protein components SGP-1 and SGP-2 were 0.99 mmol/L,(109±1.56)μmol TE/mg and 0.59 mmol/L,(65±1.42)μmol TE/mg,respectively.The antioxidant activities of both samples showed concentration dependence within a certain mass concentration range,and the SGP-1 exhibited better antioxidant activities than SGP-2.