Table 2.
Ultrasound combined chemical methods application in microbial reduction of fruits and vegetables
| Material | Conditions | Microbial reduction | References |
|---|---|---|---|
| Organic lettuce | Ultrasound (30 W L-1, 40 kHz, 5 min, 20 °C) + malic acid, lactic acid, and citric acid (2%) | Escherchia coli: 2.75 lg CFU g−1; Salmonella Typhimurium: 3.18 lg CFU g−1; Listeria monocytogenes: 2.87 lg CFU g−1 | [5] |
| Romaine lettuce | Ultrasound (200 W, 26 kHz, 5 min, <45 °C) + thyme essential oil (0.018%) | Salmonella enterica: 3 lg CFU cm−2 | [35] |
| Plum fruit | Ultrasound (100 W, 40 kHz, 10 min, 20 °C) + aqueous chlorine dioxide (40 mg L-1) | Aerobic mesophilic bacteria: 3 lg CFU g−1; Aerobic psychrotrophic bacteria: 2.9 lg CFU g−1; Mould and yeast: 2 lg CFU g−1 | [50] |
| Carrots | Ultrasound (30 W L-1, 40 kHz, 5 min, 20 °C) + Tween 20 (0.1%) | Bacillus cereus spores: 2.22 lg CFU g−1 | [64] |
| Spinach | Ultrasound (400 W L-1, 40 kHz, 3 min, 23 °C) + slightly acidic electrolyzed water + water wash | Total bacterial count: 2.08 lg CFU g−1; Escherichia coli O157:H7: 2.41 lg CFU g−1; Listeria monocytogenes: 2.49 lg CFU g−1 | [65] |
| Kiwifruit | Ultrasound (368 W cm−2, 40 kHz, 8 min, 25 °C) + sodium hypochlorite (30 mg L-1) | Bacteria: 3.48 lg CFU g−1; Mould and yeast: 2.32 lg CFU g−1 | [66] |
| Strawberry | Ultrasound (500 W, 40 kHz, 5 min, 7 °C) + peracetic acid (40 mg L-1) | Mould and yeast: 1.8 lg CFU g−1; Mesophilic aerobic bacteria: 2 lg CFU g−1; Salmonella enterica: 2.1 lg CFU g−1 | [67] |
| Green asparagus | Ultrasound (360 W, 40 kHz, 10 min) + acetic acid (2%) + gibberellic acid (50 mg kg−1) | Bacteria: 2 lg CFU g−1; Mould and yeast: 2 lg CFU g−1 | [38] |
| Chinese cabbage | Ultrasound (120 W L-1, 40 kHz, 10 min, 30 °C) + sodium hypochlorite (100 mg L-1) | Listeria innocua: 3.35 lg CFU g−1 | [68] |
| Cherry tomato | Ultrasound (300 W, 20/40 kHz, 10 min, 25 °C) + aqueous ozone (0.85 mg L-1) | Mesophilic acteria: >3.00 lg CFU g−1; Mould and yeast: >3 lg CFU g−1 | [69] |
| Blueberries | Ultrasound (500 W, 20 kHz, 15 min, 18–22 °C) + citral (10 mM) | Listeria innocua: >2 lg CFU mL−1 | [70] |