Impact of ozonation process on the antioxidant status in blackcurrant Ribes nigrum L. fruit

BACKGROUND: Ozonation is promising method for prolonging the postharvest shelf life as well as decrease of microbiological contamination and pesticide residue in soft fruit. In view of the fact, that ozone is a substance that can induce the reactive oxygen species generation in plant cells, it is necessary to determine the effect of ozone treatment on the antioxidant status in fruit. OBJECTIVE: The purpose of this study was to investigate the impact of ozonation on the antioxidant status in blackcurrant fruit. METHODS: Blackcurrants were exposed to ozone at the concentration of 16 mg L-1 and 160 mg L-1 for 5, 15 and 30 min. Changes in antioxidant activity, total phenolic content and activity of selected antioxidant enzymes after ozonation were analyzed. RESULTS: It was found, that under proposed conditions the activity of enzymes involved in scavenging of reactive oxygen species (quaiacol peroxidase, ascorbate peroxidase and catalase) increased with ozone concentration and treatment time. In addition, the ozone treatment activated the phenylalanine ammonia-lyase, whose an activity showed a strong correlation with total phenolic content and antioxidant activity of blackcurrants. CONCLUSIONS: Ozonation process activated a protective mechanisms against occurrence of oxidative stress in blackcurrant fruit.