TABLE 3.
Applications of pulsed electric fields to improve the extraction of phenolic compounds during red winemaking.
| Technology | Sample (volume) | Operation parameters | Main results respect to control treatment | References |
|
PEF Discontinuous process |
Red grape must (Garnacha, Mazuelo, and Graciano) 25 g |
2–10 kV cm–1, 0.4–6.7 kJ kg–1, 50 pulses, 1 Hz, < 30°C |
Must from three varieties: Extraction of anthocyanins and total phenols increase as PEF intensity increases Mazuelo grape must: Maximum extraction at 120 h (10 kV cm–1): • Anthocyanins: 41.8% higher than control • Total phenols: 31% higher than control Red wines (Garnacha, Mazuelo, Graciano): • Anthocyanins: 11.3, 16.3, 7.6% higher control, respectively • Total phenols: 14.2, 14.2, 12.1% higher control, respectively |
(117) |
|
PEF Continuous process |
Red grape must (Cabernet Sauvignon) 118 kg h–1 |
2–7 kV cm–1, 0.56–6.76 kJ kg–1, 50 pulses, pulse width 3 μs, 0.41 s, 122 Hz, < 23°C |
Must/wine: Maximum extraction at 96 h (5 kV cm–1): • Anthocyanins: 40% higher than control • Total phenols: 30% higher than control |
(179) |
|
PEF Continuous process |
Red grape must (Garnacha) 4,500 kg at 1,900 kg h–1 |
4 kV cm–1, 1.5 kJ kg–1, 20 pulses, pulse width 3 μs, 60 μs, 0.41 s, 250 Hz |
Must/wine: After 7 days of maceration: • Color intensity: 12.5% higher • Anthocyanin content: 25% higher • Polyphenol index: 23.5% higher |
(174) |
|
PEF Discontinuous process |
Red grape must (Pinot Noir) 200 g |
1.5 kV cm–1, 14.48 and 69.99 kJ kg–1, 243 and 1,033 pulses, pulse width 20 μs, 50 Hz, < 25°C | • Maximum extraction of malvidin-3-O-glucoside (224% higher) after 8 days of maceration • Maximum extraction of total phenols (61% higher) after 4 days of maceration • Bioprotective capacity of Caco-2 cells against H2O2 exposure (> 25% for cell viability) after 8 days of maceration |
(124) |
|
PEF Discontinuous process |
Red grape must (Pinot Noir and Merlot) 5 kg |
7 kV cm–1, 178 Hz |
Grape must (Merlot/Pinot Noir): • Total phenols: 1.54- and 3.16-fold higher, respectively • Total flavonoids: 1.42- and 4.96-fold higher, respectively • Monomeric anthocyanins: 1.14- and 2.35-fold higher, respectively • Antioxidant capacity: up to 5.93- and 3.90-fold higher, respectively Red wine (Merlot/Pinot Noir): • Total phenols: 1.72- and 2.98-fold higher, respectively • Total flavonoids: 2.66- and 6.21-fold higher, respectively • Monomeric anthocyanins: 1.05- and 1.11-fold higher, respectively • Antioxidant capacity: up to 2.18- and 5.77-fold higher, respectively |
(180) |
|
PEF Continuous process |
Red grape must (Grenache) 600 kg h–1 |
0.7–7.8 kV cm–1, 78–5,000 μs, 12–290 Hz |
Red wines from PEF treated musts Fresh fermented wine/after 12 months of bottle storage • Anthocyanins: up to 61%/44% higher, respectively • Condensed tannins: up to 30%/10% higher, respectively Reduction of maceration time up to 37% |
(118) |
|
PEF Continuous process |
Red grape must (Merlot) 500 kg h–1 |
33.1–41.5 kV cm–1, 4.7–49.4 kJ L–1, 2–25 Hz |
Grape must: •↑ total phenolic content (23–162% higher) •↑ malvidin-3-O-glucoside (17–636% higher) Must/wine: Equivalent contents of malvidin-3-O-glucoside and phenolic content at: • PEF-treated: after 1 day of cold maceration • PEF-untreated: after 4 days of cold maceration |
(116) |
|
PEF Continuous process |
Red grape must (Sangiovese) 50 kg at 200–300 L h–1 |
0.9–3.0 kV cm–1, 10.4–32.5 kJ kg–1, 712–1,069 pulses, 0.48–0.71 s, 1,500 Hz |
Must*: • PEF: ↑ total phenolic content (25%) • PEF + dm: ↑ total phenolic content (27%) • PEF + dm + sm: ↑ total phenolic content (42%) Wine from PEF + dm + sm musts (3 months of storage): •↑ total phenolic content (40%) •↑ Fe-reactive polyphenols (29%) •↑ tannins (61%) •↑ protection against oxidation (> 1.4-fold higher) ** |
(130) |
|
PEF Continuous process |
Red grape must (Rondinella) 200 kg at 250 L h–1 Rondinella: low-color red grape |
1.5 kV cm–1, 2–20 kJ L–1, pulse width 3 μs, 400 Hz |
Red wine from PEF treated must (10 and 20 kJ kg–1) 2 months of bottle storage •↑ content of anthocyanins (32 and 36% higher, respectively) •↑ content of tannins (64 and 64% higher, respectively) 12 months of bottle storage •↑ content of anthocyanins (3.8 and 50% higher, respectively) •↑ content of tannins (38 and 50% higher, respectively) |
(129) |
|
PEF Continuous process |
Red grape must (Grenache) 12,000 kg at 2,500 kg h–1 |
4.3 kV cm–1, 6.2 kJ kg–1, 3.7 square pulses of 100 μs |
Fresh fermented wine • Anthocyanins: up to 37% higher • Tannins content: up to 40% higher 24 months of bottle aging • Total anthocyanins: up to 110% higher • Total hydrocinnamic acids: up to 167% higher • Total flavonols: up to 200% higher • Total flavanols: up to 28% higher 6 months of oak barrel aging + 18 months of bottle aging • Total anthocyanins: up to 81% higher • Total hydrocinnamic acids: up to 152% higher • Total flavonols: up to 189% higher • Total flavanols: up to 96% higher |
(128) |
|
PEF Continuous process |
Red grape must (Grenache) 100 kg at 120 kg h–1 |
5–17.5 kV cm–1, 63.4–115 kJ kg–1, 45 pulses, 0.38–0.24 s, 120 kg/h |
Red wine fermented by non-Saccharomyces yeasts Depending on the used yeast-strain: •↑ content of pyranoanthocyanins (up to 30% higher) •↑ content of vitisin A (up to 89% higher) |
(115) |
|
PEF Discontinuous process |
Red grape pomace | 3 kV cm–1, 10 kJ kg–1, 30 pulses, 15 s, 2 Hz, 70°C |
•↑ total phenolic content (> 1.5-fold higher) •↑ extraction of anthocyanin monoglucosides (> 1.4-fold higher) •↑ extraction of acylated anthocyanins (> 7.9-fold higher) •↑ antioxidant activity (> 4-fold higher) |
(102) |
*Results respect to control for each treatment (without PEF application). dm, dynamic maceration 2 h; sm, static maceration 12 h.
** Oxidative process: monitored by the evolution of the hue (evolution from red-blue to red-brown tonalities).