Table 2.
25−1 factorial design with process parameters of solid/liquid extraction and experimentally obtained values of total polyphenol (TP) content, antioxidant activity (DPPH), and ellagic acid content. Citric acid monohydrate, betaine (1 mol), and water were used for NADES formulation.
| Sample | A: Temperature [°C] | B: Moles of Citric Acid Monohydrate | C: Water Content [g/100 g] |
D: Time [min] |
E: NADES/Plant Ratio [g/g] |
TP [mg GAE 1/g DW] |
DPPH [μM TE 2/g DW 3] |
Ellagic Acid [mg/100 g DW] |
Ellagic Acid [mg/100 g Extract] |
|||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solid/liquid extraction | ||||||||||||||
| 1 | −1 | 60 | 1 | 3 | 1 | 25 | 1 | 60 | −1 | 10 | 34.01 ± 1.05 a,b,c,d | 650.43 ± 4.28 c,d,e | 45.66 ± 0.24 a,b | 3.45 ± 0.09 d |
| 2 | 1 | 70 | 1 | 3 | −1 | 20 | 1 | 60 | −1 | 10 | 33.25 ± 2.60 a,b,c,d | 637.13 ± 12.26 c | 52.56 ± 0.03 c,d | 3.91 ± 0.01 f |
| 3 | 1 | 70 | 1 | 3 | 1 | 25 | 1 | 60 | 1 | 20 | 37.21 ± 0.32 e,f | 427.99 ± 9.87 a | 72.96 ± 0.90 f | 2.74 ± 0.05 c |
| 4 | 1 | 70 | 1 | 3 | 1 | 25 | −1 | 30 | −1 | 10 | 35.15 ± 1.33 b,c,d,e,f | 679.23 ± 10.31 d,e | 49.30 ± 0.17 b,c | 3.64 ± 0.01 e |
| 5 | 1 | 70 | −1 | 2 | 1 | 25 | −1 | 30 | 1 | 20 | 36.62 ± 1.41 d,e,f | 454.28 ± 11.16 a,b | 65.33 ± 0.89 e | 2.50 ± 0.04 a,b |
| 6 | −1 | 60 | 1 | 3 | −1 | 20 | −1 | 30 | −1 | 10 | 33.70 ± 0.43 a,b,c,d,e | 632.19 ± 11.41 c | 45.25 ± 1.79 a | 3.39 ± 0.09 d |
| 7 | 1 | 70 | −1 | 2 | −1 | 20 | 1 | 60 | 1 | 20 | 35.21 ± 0.93 b,c,d,e,f | 447.31 ± 2.09 a,b | 70.67 ± 0.94 f | 2.64 ± 0.02 b,c |
| 8 | −1 | 60 | 1 | 3 | −1 | 20 | 1 | 60 | 1 | 20 | 31.48 ± 0.80 a | 480.17 ± 17.37 b | 62.56 ± 0.71 e | 2.41 ± 0.01 a |
| 9 | −1 | 60 | −1 | 2 | −1 | 20 | 1 | 60 | −1 | 10 | 32.20 ± 0.87 a,b | 643.54 ± 2.12 c,d | 45.00 ± 0.19 a | 3.42 ± 0.01 d |
| 10 | 1 | 70 | 1 | 3 | −1 | 20 | −1 | 30 | 1 | 20 | 32.77 ± 0.28 a,b,c | 451.86 ± 14.34 a,b | 64.18 ± 0.95 e | 2.43 ± 0.03 a |
| 11 | −1 | 60 | −1 | 2 | 1 | 25 | −1 | 30 | −1 | 10 | 36.05 ± 0.66 c,d,e,f | 655.80 ± 3.56 c,d,e | 47.33 ± 2.17 a,b | 3.52 ± 0.14 d,e |
| 12 | 1 | 70 | −1 | 2 | −1 | 20 | −1 | 30 | −1 | 10 | 32.74 ± 1.63 a,b,c | 641.05 ± 12.33 c | 45.35 ± 0.78 a,b | 3.43 ± 0.01 d |
| 13 | −1 | 60 | −1 | 2 | 1 | 25 | 1 | 60 | 1 | 20 | 36.29 ± 0.10 c,d,e,f | 455.17 ± 3.03 a,b | 69.43 ± 3.87 f | 2.56 ± 0.09 a,b |
| 14 | −1 | 60 | −1 | 2 | −1 | 20 | −1 | 30 | 1 | 20 | 33.84 ± 0.44 a,b,c,d,e | 436.22 ± 11.59 a | 64.71 ± 0.47 e | 2.46 ± 0.03 a |
| 15 | 1 | 70 | −1 | 2 | 1 | 25 | 1 | 60 | −1 | 10 | 38.72 ± 1.90 f | 682.23 ± 29.08 e | 53.50 ± 0.14 d | 3.94 ± 0.03 f |
| 16 | −1 | 60 | 1 | 3 | 1 | 25 | −1 | 30 | 1 | 20 | 35.08 ± 1.19 b,c,d,e | 474.21 ± 14.51 b | 65.24 ± 0.29 e | 2.45 ± 0.02 a |
| Additional experiments with ultrasound-assisted extraction | ||||||||||||||
| 17 | 1 | 70 | 1 | 3 | −1 | 20 | 1 | 60 | −1 | 10 | nd | nd | 47.58 ± 0.23 | 2.06 ± 0.02 |
| 18 | 1 | 70 | −1 | 2 | 1 | 25 | 1 | 60 | −1 | 10 | nd | nd | 51.30 ± 2.58 | 2.11 ± 0.11 |
1 Galic acid equivalent; 2 Trolox equivalent; 3 Dry weight of defatted raspberry seeds; Nd—not determined. 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.