玉米肽的纳滤脱盐工艺及脱盐产物抗氧化活性

以具有抗氧化活性的玉米肽为原料，首先采用150 Da纳滤膜对玉米肽进行脱盐处理，通过对膜通量、电导率、Na＋质量分数、脱盐率和纳滤后产物抗氧化活性等参数的分析，确定玉米肽的纳滤脱盐工艺，然后利用H2O2诱导的Caco-2细胞氧化损伤模型对脱盐玉米肽的抗氧化活性进行研究。结果表明：利用150 Da纳滤膜对玉米肽脱盐的工艺条件为压力20 bar、频率50 Hz、温度20 ℃、纳滤5 次，每次体积浓缩倍数为2。在此条件下，玉米肽的脱盐率为70.73%，短肽回收率达96.73%，与纳滤前相比，电导率降低了33.86%，玉米肽的1,1-二苯基-2-三硝基苯肼自由基和羟自由基清除率分别提高21.55%和35.93%，而亚铁离子螯合率降低7.38%。质量浓度为75 μg/mL的脱盐玉米肽通过显著提高细胞内的抗氧化酶（超氧化物歧化酶、谷胱甘肽还原酶、过氧化氢酶和γ-谷氨酰半胱氨酸合成酶）活力而提高由H2O2诱导的氧化性损伤Caco-2细胞的存活率。

Corn Peptide:Desalting by Nanofiltration and Antioxidant Activity

In the present study,corn antioxidant peptide was desalted using a nanofiltration membrane with molecular mass cut-off of 150 Da.The desalting process was evaluated with respect to membrane flux,conductivity,Na⁺concentration,desalting efficiency and antioxidant of nanofiltration product,and the protective effect of the desalted peptide on H2O2-induced oxidative damage in Caco-2 cell model was determined.The results showed that the desalination conditions were as follows:pressure 20 bar,frequency 50 Hz,temperature 20℃,number of nanofiltration cycles 5,and volumetric concentration factor in each nanofiltration 2.Under these conditions,the desalting efficiency was 70.73%,and the recovery of short peptide was 96.73%.Compared to that before nanofiltration,the conductivity was decreased by 33.86%,the 1,1-diphenyl-2-picrylhydrazyl(DPPH)and hydroxyl radical scavenging capacities were increased by 21.55%and 35.93%,respectively,while the ferrous ion chelating capacity was reduced by 7.38%.The desalted corn peptides at 75μg/mL remarkably increased the viability of H2O2-induced Caco-2 cells by increasing the activity of cellular antioxidant enzymes(superoxide dismutase,glutathione peroxidase,catalase,andγ-glutamylcysteine synthetase).