Table 2.
Protein recovery, protein concentration, peptide concentration, and antioxidant activity of CS protein hydrolysate.
| Extraction Time (min) | Protein Recovery (mg/g CS) | Decrease in Protein Concentration (mg/mL) | Increase in Peptide Concentration (mg/mL) | Increase in Antioxidant Activity (µmole TE/mL) |
||
|---|---|---|---|---|---|---|
| ABTS | DPPH | FRAP | ||||
| Conventional alkaline extraction (CAE) * | ||||||
| 240 | 12.26 ± 0.96 d | 0.730 ± 0.017 b | 0.261 ± 0.006 a | 0.834 ± 0.016 a | 0.891 ± 0.015 a | 0.615 ± 0.001 a |
| Ultrasound-assisted alkaline extraction (UAE) ** | ||||||
| 10 | 13.06 ± 0.71 d | 0.879 ± 0.005 ab | 0.269 ± 0.009 a | 1.073 ± 0.015 a | 1.038 ± 0.008 a | 0.607 ± 0.009 a |
| 25 | 18.31 ± 0.22 c | 0.733 ± 0.011 b | 0.240 ± 0.004 b | 0.752 ± 0.081 b | 0.640 ± 0.012 b | 0.224 ± 0.007 b |
| 40 | 18.60 ± 0.36 c | 0.679 ± 0.010 c | 0.177 ± 0.052 c | 0.507 ± 0.030 c | 0.264 ± 0.009 c | 0.041 ± 0.006 c |
| Microwave-assisted alkaline extraction (MAE) *** | ||||||
| 2 | 12.19 ± 0.39 d | 0.902 ± 0.090 a | 0.357 ± 0.020 a | 1.418 ± 0.002 a | 1.258 ± 0.051 a | 0.858 ± 0.052 a |
| 5 | 20.06 ± 0.39 b | 0.701 ± 0.016 b | 0.247 ± 0.008 b | 1.028 ± 0.028 b | 0.877 ± 0.051 b | 0.521 ± 0.002 b |
| 10 | 21.77 ± 0.32 a | 0.512 ± 0.042 d | 0.144 ± 0.001 d | 1.007 ± 0.035 b | 0.806 ± 0.006 b | 0.451 ± 0.021 b |
* Conventional alkaline extraction was performed at 50 °C. ** Ultrasound-assisted alkaline extraction was performed using 80% amplitude. *** Microwave-assisted alkaline extraction was performed using 90 W electric power. The experiments are performed in triplicate (n = 3). The results are reported as mean ± SD. Different letters (a–d) within columns are significantly different at p < 0.05 according to analysis by Duncan’s multiple range test.