Liang Rong, Li Xuenan, Lin Songyi, Wang Jia
College of Food Science and Technology, Jilin University, Changchun, 130062, P.R. China.
Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958, Frederiksberg C, Denmark.
J Sci Food Agric. 2017 Jan;97(2):578-586. doi: 10.1002/jsfa.7768. Epub 2016 Jun 3.
SAP was chosen to investigate the improvement of antioxidant activity of peptides treated with pulsed electric field (PEF) technology. The effects of electric field intensity and pulse frequency on SAP were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition, as well as the zeta potential and functional groups.
One-factor-at-a-time tests indicated that the PEF-treated sample had the strongest antioxidant activity (P < 0.05) and the lowest zeta potential value. The increase of antioxidant activity of SAP may be attributed to a loss of C = C and the amide band. Using a response surface methodology (RSM) experiment, it was shown that DPPH radical inhibition of SAP increased to 90.22 ± 0.90% at the optimal conditions (electric field intensity 15 kV cm , pulse frequency 1600 Hz and flow velocity 2.93 mL min ). Furthermore, the PEF-treated SAP under optimal conditions lacked the characteristic absorbance of N-H, C = C and the amide band and the zeta potential was reduced to -18.0 mV.
Overall, the results of the present study suggest that the improvement of antioxidant activity of SAP is a result of the contribution of the functional groups and the change in zeta potential when treated with PEF. © 2016 Society of Chemical Industry.
选择大豆抗氧化肽（SAP）来研究脉冲电场（PEF）技术处理对其抗氧化活性的改善情况。采用2,2-二苯基-1-苦基肼（DPPH）自由基抑制法以及ζ电位和官能团分析，评估电场强度和脉冲频率对大豆抗氧化肽的影响。
单因素试验表明，经脉冲电场处理的样品具有最强的抗氧化活性（P < 0.05）和最低的ζ电位值。大豆抗氧化肽抗氧化活性的提高可能归因于C = C键和酰胺带的损失。采用响应面法（RSM）实验表明，在最佳条件下（电场强度15 kV/cm，脉冲频率1600 Hz，流速2.93 mL/min），大豆抗氧化肽对DPPH自由基的抑制率提高到90.22±0.90%。此外，在最佳条件下经脉冲电场处理的大豆抗氧化肽缺乏N - H、C = C键和酰胺带的特征吸收，ζ电位降至 - 18.0 mV。
总体而言，本研究结果表明，大豆抗氧化肽抗氧化活性的提高是由于官能团的贡献以及经脉冲电场处理后ζ电位的变化所致。© 2016化学工业协会。
