优选南极磷虾蛋白肽抗氧化活性组分

目的制备南极磷虾抗氧化肽,优选出抗氧化活性最好的南极磷虾肽成分。方法采用脱脂、酶解、超滤等手段制备南极磷虾抗氧化肽;以DPPH自由基清除率、ABTS自由基清除率、抗氧化能力指数3个抗氧化指标和超氧化物歧化酶(superoxide dismutase, SOD)、过氧化氢酶(catalase, CAT)活力2个酶活力指标为评价指标,优选出抗氧化活性最好的南极磷虾肽组分;基于G-25凝胶层析技术对抗氧化活性最好的南极磷虾肽组分进行分离纯化,进一步基于电子顺磁共振(electron paramagnetic resonance,EPR)方法测定洗脱后各峰的DPPH自由基清除率,得到抗氧化活性最好的南极磷虾抗氧化肽组分。结果通过抗氧化指标测定,截留分子量3～10 KDa的肽的DPPH自由基清除率最高,为(30.10±1.10)%,截留分子量3 KDa的南极磷虾肽的ABTS清除能力和抗氧化指数较好,则IC50值为(0.74±0.08) mg/mL、氧化自由基吸收能力(oxygen radical absorbance capacity, ORAC)值为6.39±0.21;通过酶活力指标测定,截留分子量3 KDa的肽的SOD活力和CAT活力最好,分别为(45.7±0.13)U/mg和(17.1±0.19)U/mg蛋白质。对截留分子量3KDa和3～10KDa的南极磷虾肽进行G-25分离纯化后,测定各组分的DPPH自由基清除率,可知截留分子量3～10KDa的F2-2峰清除率最好,为(51.55±1.54)%。结论基于EPR方法优选出分子量为3～10 KDa的南极磷虾肽的F2-2组分的DPPH自由基清除率最高。

Optimizing the antioxidant components of Antarctic krill protein peptides

Objective To prepare antarctic krill antioxidant peptide and select the Antarctic krill peptide components with the best antioxidant activity. Methods The antioxidant peptides of Antarctic krill were prepared by means of degrease, enzymatic hydrolysis, and ultrafiltration. DPPH radical scavenging capacity, ABTS radical scavenging capacity, oxygen radical absorbance capacity, superoxide dismutase (SOD) activity and catalase (CAT) activity were used as evaluation indicators to select Antarctic krill peptide components with the best antioxidant activity. Based on G-25 gel chromatography, the Antarctic krill peptides were further separated and purified. The DPPH free radical removal rate of the elution peaks was determined by using the electron paramagnetic resonance (EPR) method, and the Antarctic krill antioxidant peptide component with the maximal antioxidant activity was obtained. Results From the results of antioxidant indicators, the Antarctic krill peptides with the molecular weight of 3-10 KDa peptide have the best DPPH radical scavenging capacity (30.10%±1.10%); the Antarctic krill peptides with the molecular weight of <3 KDa have the best ABTS radical scavenging capacity (0.74 mg/mL±0.08 mg/mL) and antioxidant index (6.39±0.21). From the results of enzymatic activity, the Antarctic krill peptides with the molecular weight of <3 KDa produced higher SOD and CAT activity than other components. After the purification by G-25 gel chromatography, the F2-2 peak of Antarctic krill peptides with the molecular weight of 3-10 KDa generated the maximal DPPH radical scavenging capacity (51.5±1.54 %) measured by the EPR method. Conclusion Based on the EPR method, the highest DPPH free radical scavenging capacity is derived from the F2-2 component of Antarctic krill peptides with the molecular weight of 3-10 KDa.