College of Food Science and Technology, Jilin University, Changchun 130062, PR China; School of Food Science and Technology, Dalian Polytechnic University, Engineering Research Center of Seafood of Ministry of Education, Dalian 116034, PR China.
College of Food Science and Technology, Jilin University, Changchun 130062, PR China.
Food Chem. 2016 Dec 15;213:588-594. doi: 10.1016/j.foodchem.2016.07.017. Epub 2016 Jul 5.
Recently, high-intensity pulsed electric field (PEF) has successfully used in improvement of antioxidant activity. Ser-His-Cys-Met-Asn (SHCMN) obtained from soybean protein was chosen to investigate the phenomenon of antioxidant activity improvement. Effects of PEF treatment on antioxidant activity of SHCMN were evaluated by DPPH radical inhibition. Nuclear magnetic resonance (NMR), mid-infrared (MIR), circular dichroism (CD) were used to analyze structures of SHCMN. Two-factor-at-a-time results show that DPPH radical inhibition of SHCMN is significantly (P<0.05) increased to 94.35±0.03% at conditions of electric field intensity of 5kV/cm, pulse frequency of 2400Hz, and retention time of 2h. In addition, MIR and NMR spectra show that the basic structure of peptides SHCMN is stable by PEF treatment. But the secondary structures (α-helix, β-turn, and random coil) can be affected and zeta potential of PEF-treated SHCNM was reduced to 0.59±0.03mV. The antioxidant activity improvement of SHCMN might result from the changes of secondary structures and zeta potential.
最近，高强度脉冲电场（PEF）已成功用于提高抗氧化活性。选择大豆蛋白中获得的 Ser-His-Cys-Met-Asn（SHCMN）来研究抗氧化活性提高的现象。通过 DPPH 自由基抑制评估 PEF 处理对 SHCMN 抗氧化活性的影响。使用核磁共振（NMR）、中红外（MIR）、圆二色性（CD）分析 SHCMN 的结构。两因素析因结果表明，在电场强度为 5kV/cm、脉冲频率为 2400Hz 和保留时间为 2h 的条件下，SHCMN 的 DPPH 自由基抑制率显著（P<0.05）提高至 94.35±0.03%。此外，MIR 和 NMR 光谱表明，PEF 处理后肽 SHCMN 的基本结构稳定。但是二级结构（α-螺旋、β-转角和无规卷曲）可能会受到影响，PEF 处理的 SHCNM 的 ζ 电位降低至 0.59±0.03mV。SHCMN 的抗氧化活性提高可能归因于二级结构和 ζ 电位的变化。
