Effects on functional groups and zeta potential of SAP1<MW<3kDatreated by pulsed electric field technology.
BACKGROUND
SAP1<MW<3kDawas 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 SAP1<MW<3kDawere evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition, as well as the zeta potential and functional groups.


RESULTS
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 SAP1<MW<3kDamay 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 SAP1<MW<3kDaincreased to 90.22 ± 0.90% at the optimal conditions (electric field intensity 15 kV cm-1, pulse frequency 1600 Hz and flow velocity 2.93 mL min-1). Furthermore, the PEF-treated SAP1<MW<3kDaunder 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.


CONCLUSIONS
Overall, the results of the present study suggest that the improvement of antioxidant activity of SAP1<MW<3kDais a result of the contribution of the functional groups and the change in zeta potential when treated with PEF. © 2016 Society of Chemical Industry.
College of Food Science and Technology, Jilin University, Changchun, 130062, P.R. China.
Rong
R
Liang
College of Food Science and Technology, Jilin University, Changchun, 130062, P.R. China.
Xuenan
X
Li
College of Food Science and Technology, Jilin University, Changchun, 130062, P.R. China.
Songyi
S
Lin
Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958, Frederiksberg C, Denmark.
Jia
J
Wang
D000975:Antioxidants / Q000737:chemistry*; D019587:Dietary Supplements; D055664:Electrochemical Techniques; D005520:Food Preservatives / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry*; D014674:Plant Proteins, Dietary / Q000737:chemistry*; D030262:Soybean Proteins / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013223:Statistics as Topic; D013499:Surface Properties
D000975:Antioxidants; D005520:Food Preservatives; D016166:Free Radical Scavengers; D010446:Peptide Fragments; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins
functional groups; pulsed electric field; soybean antioxidant peptides; zeta potential