Table 3.
In vitro evaluation of total phenolic content and antioxidant and antimicrobial activities.
| Source | Method and Activity | Ref. |
|---|---|---|
| Phenolic content and antioxidant activity | ||
| Apple peel extract | TPC: 1.39–3.30 g GAE/100 g dry weight TFC: 1.15–2.04 g QE/100 g |
[79] |
| Date extract | TPC: 2.74–3.60 µg GAE/mL TFC: 4.77–9.06 µg CE/mL DPPH: 720–1.120 µmol Trolox/mL ABTS: 621–774 µmol Trolox/mL |
[80] |
| Grape pomace | TPC: 20–35.0 mg GAE/g dry weight | [81] |
| Grape extract | TPC: 10.99 mg GAE/100 mL DPPH: 10.17% inhibition |
[82] |
| Jabuticaba peel extract | TPC: 13.22 mg GAE/mL FRAP: 5.76 μmol Trolox/L DPPH: 36.03 mmol Trolox/L |
[83] |
| Jabuticaba peel extract | TPC: 18.51 mg GAE/mL DPPH: 36.75 µg TEAC/mL |
[84] |
| Kiwifruit extract | TPC: 21.32 mg GAE/100 mL DPPH: 19.84% inhibition |
[82] |
| Olive extract | TPC: 41.4 mg GAE/g ABTS: 79.6% inhibition DPPH: 78.0% inhibition ORAC: 140.5 µM Trolox FRAP: 71.2 µM Trolox |
[85] |
| Pomegranate peel powder | TPC: 215.2 mg/g TFC: 70.4 mg/g DPPH (EC50): 17.8 μg/mL |
[42] |
| Pomegranate peel extract powder | TPC: 101–169 mg GAE/100 g | [86] |
| Pomegranate extract | TPC: 33.15 mg GAE/100 mL DPPH: 20.34% inhibition |
[82] |
| Pomegranate byproduct extract | TPC: 127.51 mg GAE/100 mL DPPH: 93.61% inhibition |
[82] |
| Red pitaya pulp extract | TPC: 268.13 mg of GAE/100 g DPPH (EC50): 229 mg Trolox/100 g FRAP: 825.40 μmol Fe+2/100 g. |
[87] |
| Watermelon rind extract | DPPH: 77.46% inhibition ABTS: 75.57% inhibition FRAP: 77.5 mM Fe2+/mL SASA: 47.5% inhibition |
[88] |
| Antimicrobial activity | ||
| Citrus unshiu peel extract |
Bacillus cereus (MIC): 10–20 mg/mL Staphylococcus aureus (MIC): 10–20 mg/mL Listeria monocytogenes (MIC): 10–20 mg/mL |
[89] |
| Olive extract |
Escherichia coli (IZ): 11 mm Listeria monocytogenes (IZ): 6–13 mm Staphylococcus aureus (IZ): 8–25 mm |
[85] |
| Orange peel essential oil |
Bacillus subtilis (IZ): 7.0–7.5 mm Candida albicans (IZ): 10–12 mm Pseodomonas aeruginosa (IZ): 10.5–13 mm Stapylococcus aureus (IZ): 8.5–12.5 mm Escherichia coli (IZ): 9.5–12.0 mm |
[72] |
| Pomegranate peel extract | Pseudomonas putida (IZ): 3–8 mm | [90] |
| Pomegranate peel extract powder |
Bacillus cereus (IZ): 13–19 mm Escherichia coli (IZ): 12–17 mm Pseudomonas aeruginosa (IZ): 12–16 mm Staphylococcus aureus (IZ): 13–19 mm |
[86] |
| Pomegranate peel extract | Penicillium digitatum (IZ): 0.3–4.1 mm | [91] |
ABTS: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); CE: catechin equivalent; DPPH: 2,2-diphenyl-1-picrylhydrazyl; EC50: extract concentration decreasing the initial DPPH radical concentration by 50%; FRAP: ferric-reducing ability of plasma; GAE: gallic acid equivalent; IZ: inhibition zone; MIC: minimum inhibitory concentration; ORAC: oxygen radical absorbance capacity; QE: quercetin Equivalent; SASA: superoxide anionic scavenging activity; TFC: total flavonoid content; and TPC: total phenolic content.