Effect of cultivar x ozone treatment interaction on the total polyphenols content and antioxidant activity of globe artichoke

Two globe artichoke cultivars (Violet de Provence and Apollo) were harvested at an experimental field in Sicily, immediately washed with ozonised water and stored in: i) normal atmosphere; ii) ozone-enriched atmosphere for 3 days and for the last 4 days in normal atmosphere; iii) ozone-enriched atmosphere for 7 days. A control (samples unwashed and stored at room temperature) was also investigated. The effect of cultivar x ozone treatment interaction on water content losses, total polyphenols content and antioxidant activity was evaluated after 0, 3 and 7 days of storage. Washing with ozonised water and storage under O₃^- enriched atmosphere allowed higher water retention compared with the control, especially for Violet de Provence. After 3 days of storage in ozone-enriched atmosphere, on average of cultivars, the total polyphenols content and antioxidant activity increased by 11.7% and 5.5%, respectively. By contrast, after further 4 days of storage in ozonised atmosphere, Apollo and Violet de Provence displayed a significant reduction in their level of total polyphenols and aantioxidant activity. The exposure of globe artichoke heads to an ozone-enriched atmosphere should not exceed 3 days aimed at preserving their high nutritional value, with special emphasis on total polyphenols content.