Table 1.
Four antioxidant activity levels of peptides after purification.
| The Source of Peptides | ABTS Radical Scavenging Activity (%) | DPPH Radical Scavenging Activity (%) | OH Radical Scavenging Activity (%) | Ferric Reducing Antioxidant Power |
|---|---|---|---|---|
| WPI hydrolysate | 53.44 ± 0.53 b | 8.34 ± 0.09 b | 79.91 ± 0.85 b | 0.297 ± 0.001 b |
| Top phase of ATPE | 68.53 ± 0.50 c | 15.98 ± 0.03 c | 85.98 ± 0.38 c | 0.361 ± 0.001 c |
| Bottom phase of ATPE | 34.81 ± 0.49 a | 5.98 ± 0.17 a | 51.26 ± 0.33 a | 0.167 ± 0.003 a |
| Top phase of ATPF | 81.88 ± 0.68 d | 23.68 ± 0.07 d | 89.72 ± 0.64 d | 0.403 ± 0.001 d |
The data (mean ± standard deviation) derived from three replicates, as described in the Materials and Methods section. a–d means in the same column with different superscripts are significantly different (P ˂ 0.01); ABTS: 2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate); DPPH: 2,2-diphenyl-1-picrylhydrazyl; OH radical: hydroxyl radical (OH radical); WPI: whey protein isolate; ATPE: Aqueous two-phase extraction; ATPF: Aqueous two-phase flotation.