Table 5.
Experimental results of total phenolic content (TPC), total flavonoid content (TFC) and DPPH assay for the ultrasound-assisted extraction of bioactive compounds from Spanish saffron floral-by products, and for Greek saffron stigmas extracted with the optimal UAE conditionsa.
| Extraction | UAE Conditions |
Responses |
|||||
|---|---|---|---|---|---|---|---|
| Time (min) | Power (W) | NaDES (Pro/Gly 1:2) (%) | TPC (mg GAE/g dw) | TFC (mg CE/g dw) | DPPH Scavenging Ability, IC50 (mg of extract/mL) | ||
| Saffron floral by-products | 1 | 35 | 180 | 60 | 42.27 ± 2.55b | 3.60 ± 0.32cde | 6.64 ± 0.24b |
| 2 | 20 | 60 | 30 | 27.89 ± 0.61cde | 3.10 ± 0.07e | – | |
| 3 | 20 | 120 | 60 | 27.10 ± 0.83cde | 3.67 ± 0.08cde | – | |
| 4 | 20 | 120 | 60 | 28.21 ± 2.41cd | 4.60 ± 0.04abc | – | |
| 5 | 35 | 60 | 60 | 29.38 ± 2.13c | 4.93 ± 0.25 ab | – | |
| 6 | 20 | 180 | 30 | 22.15 ± 0.02efg | 3.15 ± 0.08e | – | |
| 7 | 5 | 60 | 60 | 26.66 ± 0.45cdef | 4.54 ± 0.03abcd | – | |
| 8 | 20 | 60 | 90 | 5.99 ± 0.15h | 1.30 ± 0.06f | – | |
| 9 | 20 | 180 | 90 | 88.96 ± 1.08a | 4.36 ± 0.48bcd | 2.06 ± 0.15a | |
| 10 | 35 | 120 | 90 | 20.17 ± 0.67g | 0.60 ± 0.11f | – | |
| 11 | 20 | 120 | 60 | 29.26 ± 0.58c | 4.77 ± 0.14 ab | – | |
| 12 | 20 | 120 | 60 | 27.49 ± 2.23cde | 5.49 ± 0.05a | – | |
| 13 | 35 | 120 | 30 | 26.01 ± 2.57cdefg | 3.02 ± 0.13e | – | |
| 14 | 5 | 120 | 90 | 31.56 ± 0.09c | 2.73 ± 0.24e | 6.36 ± 0.51b | |
| 15 | 5 | 180 | 60 | 23.24 ± 1.68defg | 3.59 ± 0.42de | – | |
| 16 | 5 | 120 | 30 | 21.17 ± 0.78 fg | 2.75 ± 0.56e | – | |
| Saffron stigmas | 20 | 180 | 90 | 95.66 ± 9.34 | 9.56 ± 0.60 | 2.74 ± 0.47 | |
a
Means ± standard deviation in the same column followed by different lowercase letters indicate statistically significant differences at (p ≤ 0.05) for each sample (n = 3).