Ozone Treatment Induces Changes in Antioxidative Defense System in Blueberry Fruit During Storage

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 degrees 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 degrees 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.