. 2021 Apr 1;10(4):748. doi: 10.3390/foods10040748

Table 3.

Effect on the quality parameters and microbiological control of fresh-cut vegetables treated with gaseous ozone.

Vegetables	Treatment	Qualitative Results	Microbiological Results	References
Rocket	Gaseous ozone 1, 2 and 5 ppm	Fresh-cut rocket was not adversely affected by the UV-C (5, 10 and 20 kJ m⁻²) and ozone (1, 2 and 5 ppm) treatment, maintaining the sensory quality during cold storage.	The 20 kJ UV-C m ⁻² treatment was found to be better than the chlorine and gaseous ozone treatments, in terms of reducing the microbial load in fresh-cut rocket.	Gutiérrez et al., 2017 [97]
Green Peppers	Gaseous ozone 6.42 mg cm⁻³ for 15 min	The three treatments (ozone, modified atmosphere packaging and ozone + MAP) all reduced respiration rates and malondialdehyde (MDA) content compared to the control group. The enzyme activities in fresh-cut green peppers including peroxidase (POD), superoxidase dismutase (SOD) and L-phenylalanin ammonia-lyase (PAL) were induced by ozone and MAP treatments, while polyphenol oxidase (PPO) activities were inhibited.		Chen et al., 2016 [98]
Lettuce, spinach and parsley	Gaseous ozone 950 μL L⁻¹, 20 min Aqueous ozone 12 mg L⁻¹	AO does not affect chemical characteristics of the vegetables (chlorophyll a, chlorophyll b, ascorbic acid and total phenolic contents and antioxidant activity). GO caused significant losses in important bioactive compounds of parsley. Ascorbic acid and total phenolic contents and antioxidant activity in ozone-treated samples were 40.1, 14.4 and 41.0%, respectively, less than the control samples.	Aqueous ozone: chlorine and ozone washes resulted in average log units reductions of 2.9 and 2.0 for E. coli in the vegetables tested, respectively, while the efficiency of ozone (2.2 log) was very close to that of chlorine (2.3 log) on L. innocua. GO treatment resulted in 1.0–1.5 log reductions in the numbers of E. coli and L. innocua in parsley.	Karaca and Veliogu, 2014 [99]
Bell peppers	Aqueous ozone 1 μL L⁻¹ Gaseous ozone 0.7 μL L⁻¹	In all the experiments, O₂ continuously decreased and CO₂ concentration increased. The pH value increased and a significant softening was observed in all the fruits. By day 14, L values decreased in all the fruits, with the greatest changes found in the chlorinated samples (approximately 12 units). The aqueous solutions, ozonated (1 μL L⁻¹) and chlorine (200 μL L⁻¹) water showed greater changes in the quality attributes with increasing washing times. The GO treatment did not affect any of the physicochemical attributes studied.	The exposure for three min to gaseous ozone reduced the mesophiles, psychrotrophes and fungal populations of the fresh-cut peppers in 2.5, 3.3 and 1.8 log units, respectively, compared to ozone treatment in water.	Horvitz et al., 2014 [100]
Tomato slices	Gaseous ozone 0.4 mg L⁻¹ for 1, 3 and 5 min	The poor appearance, aroma and overall quality obtained in all treatments.	It is recommended to wash tomato slices with 0.4 mg L⁻¹ ozonated water for 3 min only. Extending treatment duration did not improve the microbiological quality, possibly due to the extra time permitting the ozone to react with other components of the fruit tissue, undermining the antimicrobial benefits.	Aguayo et al., 2006 [101]