In this study the effect of the ozonation procedure on the microbiological and antioxidant status of raspberries stored at room temperature was investigated. During the study, it was found that ozonation with a dose of 8–10 ppm for 30 min, every 12 hours, for 3 days effectively reduced the growth of aerobic mesophilic bacteria and fungi. On the last day of storage, infestation with Botrytis cinerea for control fruit amounted 100%, while for ozonated fruits it was only 12%. In addition, the ozonation process has preserved the high antioxidant potential of the fruits and reduced the loss of polyphenol compounds, including anthocyanin. The applied procedure was proven to be effective, showing the potential of ozone as a factor extending the high commercial and consumer value of fruit stored at room temperature.

The major aim of this study was to investigate the effect of ozonation process on the level of oxidative stress markers in blueberry fruit during cold storage (4 °C). Blueberry (Vaccinum corymbosum L.) fruit was ozonated with an ozone concentration of 15 ppm for 30 min, every 12 h for 28 days of storage at 4 °C. The results indicated that ozone treatment activated a defense mechanism against oxidative stress in blueberry fruit. Ozonated fruit was characterized by higher activity of antioxidant enzymes i.e. superoxide dismutase, glutathione peroxidase, and phenylalanine ammonia-lyase than non-ozonated fruit, over the first 21 days of storage. In turn, the level of superoxide anion radical and hydrogen peroxide in ozonated fruit was significantly lower compared with the untreated material. However, after 21 days of storage, ozone treatment contributed to the oxidative modification of protein which could be a reason of decreasing enzymes activity, involved in cell protection against oxidative stress.

The potential of the ozone-enriched atmosphere for the improvement of the shelf life of apples of Gloster variety (Malus domestica) in cold storage was investigated. The storage experiment was conducted for 84 days. During that period, ozone at the concentration of 1 ppm was dosed every 12 hours for 1 minute. However, the exposure to ozone at such a concentration was unsuccessful in terms of inhibition of fungal disease development. Furthermore, the captan level in apples was reduced; therefore, they were more susceptible to fungal disease. On the other hand, the tests of the physical properties showed that utilization of ozone slowed down the ripening of apples; therefore, extending their shelf life provided that they were not infected.