Table 3.

Overview of ozone technology use in microbiological inactivation and its effects on the safety characteristics of vegetables and fruits.

Ozone Application and Conservation Conditions	Produce and Targets	Ozone Treatment Effects in Microbiology	Ozone Treatment Effects on Physical, Chemical, and Nutritional Qualities	References
Gaseous ozone at 0 (control), 1, 3, 5, 7, and 9 ppm; 0.5, 3, 6, and 24 h; 18–20 °C; 95% RH.	Bacterial population change after ozone treatment on fresh-cut bell pepper.	Ozone at 9 ppm, for 6 h, reduced colony counts by 2.89, 2.56, and 3.06 log for E. coli O157, S. Typhimurium, and L. monocytogenes, respectively.	/	[29]
Gaseous ozone at 6.432, 10.720, and 15.008 mg/m3; 1 h; weekly occurred. Samples were put on ice by air and were processed immediately at 4 °C after arrival for 42 days.	Microbial safety and postharvest quality of cantaloupes.	Ozone failed to reduce the microbial populations at low concentrations; 15.008 mg/m3 ozone effectively reduces the microbial populations and can inhibit most of the bacteria and fungi growth.	The respiration rate and ethylene production rate were significantly lower after 15.008 mg/m3 treatment when compared with control and other groups; other factors, e.g., firmness, pectin content, titratable acidity, sarcocarp, and exocarp were significantly higher.	[57]
Gaseous ozone at 0.9 and 2.5 mg/L; 30- and 120 min; 95% RH; up to 15 days; 12 ± 1 °C.	Microbiological properties and health-related properties of Rapanui tomatoes.	Ozonised samples showed lower total amount of yeasts and moulds at 0. Ozone caused a significant reduction in yeast and mould content at day 5, 10, and 15. Ozone at 2.5 mg/L for 120 min was the most effective in bacteria inactivation.	Treatment with ozone increased the content of total soluble solids and reduced titratable acidity and maintained the total flavonoid, lycopene, total antioxidant activity, and total carotenoid content.	[58]
Gaseous ozone at 126–136 ppm; 3 min and 15 min. Ozone was produced by the dielectric barrier discharge generator.	Combinations of spoiled green beans, grape tomatoes, lettuce, and strawberries and Salmonella enterica.	Ozone exposure (126–136 ppm, 3 min and 15 min) results in 1 and 4 log reduction, respectively, in food pathogens. Periodic ozone exposure (3 min per day) result in a >5 log reduction of both bacteria and mould species.	/	[95]
Gaseous ozone at 1, 2, and 3 μg/g; 1, 2, and 3 h. Fruit samples were placed in sterile plastic bags and incubatedovernight at 4 °C.	E. coli and L. monocytogenes survival on tomato.	Ozone insignificantly reduced E. coli on tomato; ozone at 3 μg/g caused significant bacteria reduction in a time-dependent manner. For L. monocytogenes, 2 μg/g ozone caused significant bacterial reduction with short-duration exposure (1 h).	/	[43]
Aqueous ozone at 1, 1.4, 2, 2.4, and 3 mg/L; 1, 3, and 5 min. Samples were stored at 5 ± 2 °C; 85% ± 5% RH, without any initial gas injection for 16 days.	Physicochemical characteristics, microbiological qualities, and overall acceptability of shredded green bell pepper.	Ozone (>2.4 mg/L) treatments with higher durations significantly reduced the microbial load.	Ozone treatment led to better retention of ascorbic acid, firmness, colour, and overall acceptability as compared to the control samples. The shelf life was 14 days when treated with 2.4 mg/L ozone for 5 min at 5 ± 0.5 °C.	[39]
Aqueous ozone at 1.4 mg/L; 1, 5, and 10 min. Samples were stored at 4 °C for 12 days.	Pesticide residue on fresh-cut cabbage and the growth rates of aerobic bacteria, coliforms, and yeasts.	Approximately 1.2, 1.5, and 1.6 log reduction of aerobic bacteria; 0.2, 0.5, and 0.8 log reductions of coliforms; 1.1–1.4 log reduction of yeasts and a significant reduction in mould in the 1, 5, and 10 min aqueous ozone groups on day 12.	Ozone stimulated initial respiratory metabolism, reduced ethylene production, and improved the overall quality of the samples. Ozone treatment greatly removes trichlorfon, chlorpyrifos, methomyl, dichlorvos, and omethoate.	[36]
Aqueous ozone concentration at 1–5 mg/L; 2–8 min; aqueous pH 3–5.	Microbial reductions, pyruvate content, colour change, and overall acceptability of peeled onion.	Aqueous ozone at 4.51 mg/L exposed to the onions for 8 min at a pH of 3 provided the optimal microbial load reductions (3.74 logs).	The values of pyruvate content ranged from 0.107 (1 mg/L aqueous ozone for 2 min, pH 4) to 0.131 (3 mg/L aqueous ozone for 8 min, pH 3) μM/mL. Non-significant effect of ozone doses on the colour of the samples.	[38]