Table 1.
Information on published design of experiments used in extraction optimization studies of phenolics from fruit and vegetables peels
| No. | Peel material | Extraction methoda | Solvent | Design (n/r)b | Solvent to solid ratio (ml/g) | Time (min) | Tempe-rature (°C) | Other variables | TPC | ABTS assay | DPPH assay | References |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fruits | ||||||||||||
| 1 | Apple | USc | Aqueous ethanol | BBD (3/17) | 57 | 20–40 | 30–50 | Enzyme amount | 7.0 | N | N | |
| 2 | Bambangan | C | Aqueous ethanol | CCD (3/20) | 20–50 | 30 | 30–65 | Ethanol concentration | 14.6 | N | N | Prasad et al. (2011) |
| 3 | Banana | C | Methanol | CCD (3/16) | 6.7 | 21–141 | 25–55 | Number of extractions | 22 | 49 | 31 | |
| 4 | Grape | SF | Carbon dioxide | Fd (3/16) | 30 | 37–46 | Pressure and modifier | 0.44 | N | N | ||
| 5 | Grape | C | Ethanol | F (3/11) | 10–30 | 540-1740 | 25 | – | 3.22 | N | N | Casazza et al. (2012) |
| 6 | Jabuticaba | HP | Carbon dioxide | F (2/10) | 45 | 40–80 | Pressure and solid–liquid/CO2 | 13 | N | N | Santos and Meireles (2011) | |
| 7 | Mangosteen | C | Aqueous methanol | CCD (3/20) | 5.4–200 | 22–382 | 25 | Methanol (%) | 140.6 | N | N | Cheok et al. (2012) |
| 8 | Orange | US | Aqueous acetone | CCD | 250 | 5–15 | 27 | Ultrasound power and acetone concentration | 13.57 | N | N | Dahmoune et al. (2014) |
| 9 | Pomegranate | US | Aqueous ethanol | CCD (3/16) | 50 | 10–30 | 30–60 | Ethanol concentration | 91.98 | N | N | Tabaraki et al. (2012) |
| 10 | Pomegranate | C | Aqueous ethanol | CCD (3/16) | 60 | 60–300 | – | Ethanol concentration and pH | 325 | N | N | Amyrgialaki et al. (2014) |
| 11 | Rambutan | US | Water | CCD (4/30) | 10-20 | 10-30 | 30-50 | Ultrasound power | 5.52 | N | N | Prakash Maran et al. (2013) |
| 12 | Tangerine | US | Water | F (2/4) | 10 | 30–90 | 40 | Peels humidity | 19.6 | N | N | Londoño-Londoño et al. (2010) |
| 13 | Tea fruit | C | Aqueous ethanol | CCD (3/20) | 40 | 10–40 | 30-70 | Ethanol concentration | 47.5 | N | N | Xu et al. (2012) |
| Vegetables | ||||||||||||
| 14 | Potato | MW | Aqueous methanol | F (3/20) | 10 | 5–15 | – | Power and solvent % | 3.94 | N | N | Singh et al. (2011) |
| 15 | Potato | C | Water | BBD (3/17) | 20000 | 40-60 | 40-80 | 3.94 | N | 3.52 | Wijngaard et al. (2012) | |
| 16 | Potato | PL | Carbon dioxide | CCD (2/13) | 65–135 | Ethanol concentration | 3.68 | N | 3.39 | Wijngaard et al. (2012) | ||
| 17 | Potato | C | Aqueous ethanol | CCD (3/20) | 2000 | 5–150 | 25–90 | Ethanol concentration | 10.3 | N | Ye | |
TPC total phenolic content by Folin–Ciocalteau method (mg GAE/g dw), ABTS and DPPH assays (mg TE/g dw), N not included in the study)
a C conventional, HP high pressure carbon dioxide assisted, MW microwave assisted, PL pressurized liquid, SF supercritical fluid, US ultrasound assisted
b BBD Box–Behnken design, CCD Central Composite Design, F factorial design, (n number of factors/r number of runs)
cCellulase enzymolysis extraction
dOrthogonal array design L16:45
eNot expressed in TE units