Table 5.
Experimental validation of optimal conditions obtained with response surface methodology.
| Sample | A: Temperature [°C] | B: Time [min] |
C: Solvent/Plant Ratio [g/g] |
TP [mg GAE 1/g DW 2] |
DPPH [μM TE 3/g DW] |
Ellagic Acid [mg/100 g DW] |
Ellagic Acid [mg/100 g Extract] |
|||
|---|---|---|---|---|---|---|---|---|---|---|
| Predicted responses | ||||||||||
| Opt1-pred | 1 | 85 | 0.01 | 100.45 | 1 | 35 | 45.28 | 772.59 | 151.56 | 2.96 |
| Opt2-pred | 1 | 85 | 0.94 | 147.00 | −0.92 | 15.76 | 39.69 | 1125.64 | 114.48 | 5.07 |
| Experimentally obtained responses | ||||||||||
| Opt1 | 1 | 85 | 0.01 | 100.45 | 1 | 35 | 44.77 ± 1.76 c | 707.25 ± 2.87 b | 147.02 ± 7.18 c | 2.98 ± 0.13 b |
| Opt2 | 1 | 85 | 0.94 | 147.00 | −0.92 | 15.76 | 40.16 ± 1.90 b | 995.18 ± 32.08 c | 117.94 ± 5.93 b | 5.21 ± 0.17 d |
| Opt3 * | 95 | 240 | 10 | 37.97 ± 0.60 b | 679.97 ± 27.45 b | 115.62 ± 4.41 b | 7.93 ± 0.15 e | |||
| ETOH 80% | 60 | 60 | 20 | 20.67 ± 0.73 a | 197.78 ± 2.76 a | 45.23 ± 0.88 a | 1.37 ± 0.03 a | |||
| 2M HCl in MEOH | 85 | 150 | 170 | 37.33 ± 1.46 b | 4128 ± 35.91 d | 1031.41 ± 20.73 d | 4.34 ± 0.09 c | |||
1 Galic acid equivalent; 2 Trolox equivalent; 3 Dry weight of defatted raspberry seeds; Nd—not determined. Experimental results are presented as mean values ± sd (n = 3) followed by different letters which within the same row represent statistically significant differences (p < 0.05) according to post hoc Tukey’s HSD test. * NADES extract obtained with a set of conditions out of experimental domain in optimization step.