Table 2.
Antioxidant activity (mM TE/mg protein) of protein and peptide-rich fractions determined by FRAP and DPPH methods.
| Antioxidant assay1 |
Method A (Acetonitrile/water/formic acid) |
Method B (Sodium acetate solution) |
Method C (Alkaline water) |
||||
|---|---|---|---|---|---|---|---|
| F > 10 kDa | F < 10 kDa | F > 10 kDa | F < 10 kDa | F > 10 kDa | F < 10 kDa | ||
| DPPH | ETC | 30.1 ± 1.8b,A | 22.2 ± 0.1b,B | 1.7 ± 0.1b,D | 22.4 ± 1.3b,B | 18.4 ± 0.1c,C | 20.9 ± 1.2a,B |
| HTC | 16.9 ± 0.4d,B | 19.2 ± 0.2d,B | 1.9 ± 0.1a,C | 22.6 ± 1.0b,A | 16.6 ± 0.3d,B | 17.0 ± 0.1b,B | |
| Autoclaved | 39.8 ± 0.2a,A | 20.8 ± 0.1c,B | 0.9 ± 0.02c,D | 21.1 ± 1.0b,B | 21.8 ± 2.7b,B | 14.5 ± 0.2c,C | |
| Extruded | 28.1 ± 1.4b,B | 47.7 ± 0.5a,A | 2.5 ± 0.02a,D | 44.7 ± 1.5a,A | 26.1 ± 0.2a,B | 20.6 ± 1.3a,C | |
| FRAP | ETC | 3.7 ± 0.3c,D | 62.1 ± 1.6b,B | n.d.2 | 51.7 ± 1.3c,C | n.d. | 81.1 ± 1.9a,A |
| HTC | 3.4 ± 0.2c,C | 48.1 ± 3.2c,B | n.d. | 57.4 ± 1.9c,A | n.d. | 49.0 ± 0.7b,B | |
| Autoclaved | 8.6 ± 0.3b,D | 61.7 ± 1.9b,B | n.d. | 70.4 ± 3.9b,A | 1.6 ± 0.01a,E | 44.1 ± 1.6c,C | |
| Extruded | 15.5 ± 0.5a,D | 121.0 ± 3.1a,A | 3.6 ± 0.4E | 81.1 ± 3.9a,B | 0.9 ± 0.04b,F | 44.1 ± 0.2c,C | |
1
Results are means of three determinations ± standard deviation. Data followed by the same lowercase letters in the same column are not significantly different (p > 0.05). Data followed by different uppercase letters in the same line are statistically different (p < 0.05). 2n.d.: not detected. ETC = easy-to-cook (non-hardened) beans; HTC = hard-to-cook (hardened) beans.