Table 2.
Experimental design for SPI hydrolysates production and the responses evaluated for the hydrolysates
| Test | Independent variables | Evaluated responses | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| T (°C)(x 1) | pH (x 2) | E/S (U g1)(x 3) | Soluble peptides (mg mL−1) | ABTS (%) | DPPH (%) | Reducing power (Abs 700 nm) | Fe2+-chelating ability (%) | Foaming activity (%) | Emulsifying activity (%) | |
| 1 | 35 | 6.5 | 1,649 | 67.93 | 24.68 | 72.43 | 0.140 | 39.75 | 51.09 | 4.67 |
| 2 | 55 | 6.5 | 1,649 | 14.73 | 12.16 | 75.78 | 0.094 | 10.84 | 18.42 | 5.73 |
| 3 | 35 | 9.5 | 1,649 | 65.64 | 35.62 | 74.26 | 0.309 | 79.22 | 41.95 | 8.38 |
| 4 | 55 | 9.5 | 1,649 | 16.68 | 14.92 | 73.29 | 0.093 | 18.02 | 21.44 | 5.29 |
| 5 | 35 | 6.5 | 6,321 | 51.94 | 28.95 | 74.45 | 0.191 | 46.11 | 54.17 | 7.40 |
| 6 | 55 | 6.5 | 6,321 | 55.58 | 31.13 | 74.99 | 0.248 | 36.77 | 28.96 | 4.55 |
| 7 | 35 | 9.5 | 6,321 | 73.74 | 32.43 | 74.93 | 0.464 | 60.30 | 51.10 | 5.17 |
| 8 | 55 | 9.5 | 6,321 | 59.69 | 33.19 | 73.28 | 0.294 | 18.75 | 37.09 | 4.58 |
| 9 | 28.2 | 8.0 | 4,000 | 66.74 | 40.40 | 72.03 | 0.265 | 84.58 | 52.66 | 4.87 |
| 10 | 61.8 | 8.0 | 4,000 | 22.49 | 18.66 | 70.65 | 0.271 | 86.12 | 19.79 | 10.53 |
| 11 | 45 | 5.5 | 4,000 | 10.53 | 13.99 | 72.53 | 0.088 | 3.69 | 14.88 | 2.94 |
| 12 | 45 | 10.5 | 4,000 | 30.59 | 23.12 | 77.44 | 0.247 | 12.57 | 18.41 | 5.41 |
| 13 | 45 | 8.0 | 100 | 26.09 | 20.37 | 71.04 | 0.290 | 46.40 | 35.84 | 12.01 |
| 14 | 45 | 8.0 | 8,000 | 46.04 | 42.83 | 64.87 | 0.465 | 10.46 | 65.49 | 5.13 |
| 15 | 45 | 8.0 | 4,000 | 21.93 | 21.92 | 74.53 | 0.378 | 29.35 | 31.25 | 6.25 |
| 16 | 45 | 8.0 | 4,000 | 22.04 | 23.32 | 71.58 | 0.262 | 37.34 | 33.28 | 5.28 |
| 17 | 45 | 8.0 | 4,000 | 23.99 | 18.67 | 74.57 | 0.210 | 21.62 | 18.41 | 5.13 |
| Ca | 14.09 (run 7) | 10.20 (run14) | 68.62 (run 12) | 0.88 (run 14) | 45.30 (run 10) | 9.10 (run 14) | 5.13 (run13) | |||
aC = control (without enzyme), determined at the condition of maximum response