| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 6395135 | Food Research International | 2015 | 7 Pages |
Abstract
DPPH assay is widely used to evaluate the radical scavenging activities of peptides. Effects of pH and buffers on the stability of DPPH
- and its reduced product (DPPHH) in the ethanol-buffer solution were investigated in this study and the reactivity of DPPH
- towards several dipeptides was compared to that of 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS
- +) and the peroxyl radicals in oxygen radical absorbance capacity (ORAC) assay. Results showed that the deprotonation of DPPHH under basic condition could interfere with the spectrophotometric measurement at 515-525Â nm. It was suggested that the reaction mixture be maintained at a final pH range of 5.0-6.5 in 1:1 ethanol-acetate/citrate buffer medium when evaluating the activities of peptides. Additionally, among tested dipeptides, only Cys-containing dipeptides displayed DPPH
- scavenging activity with 0.14-0.28 μmol TE (Trolox equivalent)/μmol, while Tyr/Trp-containing dipeptides with high reactivity towards ABTS
- + and peroxyl radicals were inert to DPPH
- with TE values less than 0.02.
- and its reduced product (DPPHH) in the ethanol-buffer solution were investigated in this study and the reactivity of DPPH
- towards several dipeptides was compared to that of 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS
- +) and the peroxyl radicals in oxygen radical absorbance capacity (ORAC) assay. Results showed that the deprotonation of DPPHH under basic condition could interfere with the spectrophotometric measurement at 515-525Â nm. It was suggested that the reaction mixture be maintained at a final pH range of 5.0-6.5 in 1:1 ethanol-acetate/citrate buffer medium when evaluating the activities of peptides. Additionally, among tested dipeptides, only Cys-containing dipeptides displayed DPPH
- scavenging activity with 0.14-0.28 μmol TE (Trolox equivalent)/μmol, while Tyr/Trp-containing dipeptides with high reactivity towards ABTS
- + and peroxyl radicals were inert to DPPH
- with TE values less than 0.02.
Related Topics
Life Sciences
Agricultural and Biological Sciences
Food Science
Authors
Lin Zheng, Lianzhu Lin, Guowan Su, Qiangzhong Zhao, Mouming Zhao,