Table 1.
Influence of plasma treatments on phenolic compounds of uncut, fresh cut, and processed foods.
| Food | Gas (Applier and Energy Source) | Treatment Conditions | Point(s) of Assay | Effect of Plasma Treatment on Phenolic Compounds | Reference |
|---|---|---|---|---|---|
| Fresh and dried walnuts (uncut) | Ar (capillary tube, electric source) | Voltage (15 kV); frequency (12 kHz); gas flow (1 L/min); and time (3, 5, 7, 9, and 11 min) | After treatment | No effect of treatment time or storage time on TPC | [28] |
| Strawberries (uncut) | Air (dielectric barrier discharge, electric source) | Voltage discharge (60 and 80 kV) and time (1 and 5 min) | After treatment | No effect on anthocyanin content | [29] |
| Strawberries (fresh cut) | Air (dielectric barrier discharge, electric source) | Voltage (45 kV) and time (1 min) | 7 days at 4 °C | Increase TPC, flavonoid, and anthocyanin contents up to day 5 | [17] |
| Mandarin (uncut) | N2, (chamber, MW source) | MW power (900 W), frequency (2.45 GHz), vacuum, and time (10 min) | 7 at 25 °C and 28 days at 4 °C | No effect on TPC of flesh; slight increase on peel | [30] |
| Blueberries (uncut) | Air (capillary tube, electric source) | Power (549 W), frequency (47 kHz), gas flow (4 ft3/m), and time (15–120 s) | After treatment | Reduction of anthocyanin content as treatment time increased | [31] |
| Blueberry (uncut) | Air (dielectric barrier discharge, electric source) | Voltage (36 V), current (1.8 A), and time (up to 10 min) | 20 days at 25 °C | Highest anthocyanin levels were obtained using 6 and 8 min; effect lasted for 20 days | [32] |
| Dragon fruit (fresh cut) | Ar (capillary tube, RF source) | RF power (40 W) and time (60 s) | After treatment | No effect on TPC | [33] |
| Apples (fresh cut) | Air (dielectric barrier discharge, electric source) | Power (150 W), frequency (12.7 kHz), gas flow (1.5 L/min), and time (30 and 120 min) | After treatment | Reduced TPC; reduction of some procyanidin dimers and trimers (120 min) | [34] |
| Kiwi (fresh cut) | Air (dielectric barrier discharge, electric source) | Voltage (15 kV) and time (20 and 40 min) | 4 days at 10 °C | No effect on hydrophilic fraction of phenolics; slight reduction on hydrophobic fraction of phenolics after 4 days | [35] |
| Pitaya (fresh cut) | Air (dielectric barrier discharge, electric source) | Voltage (60 kV) and time (5 min) | 48 h at 15 °C | Slight increase on selected phenolic and expression of genes related to polyphenol synthesis during storage | [36] |
| Onion powder | He (chamber, MW source) | MW intensity (400 W), frequency (2.45 GHz), gas flow (1 L/min), pressure (0.7 kPa), and time (40 min) | 28 days at 4 and 25 °C | No effect on quercetin content | [19] |
| Basmati rice flour | Air (dielectric barrier discharge, RF source) | RF power (30 and 40 W), frequency (13.56 MHz), and time (5 and 10 min) | After treatment | Increase TPC content by reducing time and power | [37] |
Ar: argon, He: helium, N2: nitrogen, TPC: total phenolic content, MW: microwave, and RF: radio frequency.