Effetti dell'essiccamento sull'attività polifenolossidasica e pattern antiossidante di pomodoro ciliegino [Effects of drying process on polyphenol oxidase activity and antioxidant pattern changes of Sicilian cherry tomato]

Cherry tomatoes are characterized by relatively high levels of some antioxidants, particularly lycopene, phenols, and ascorbic acid. In Sicily, these fruits are produced in cold greenhouses with production cycles that cover all the year and sometimes can be salted and traditionally dried at high temperatures in the presence of oxygen (sun-dryng) with consequent damage of their health value. Besides, phenols are sensitive to enzymatic degradation by polyphenol oxidase (PPO, EC 1.14.18.1) during drying, so all processing operations and storage conditions must be optimised. This research aims to study the effects of hot air-drying process carried out at different temperatures on antioxidant pattern anil PPO activity in dried cherry tomatoes (15% R.U.) comparing the results with those of a traditionally sun-dried product. Cherry tomatoes hot-dried at 70°C showed a significative increase in antioxidant activity (87%), ascorbic acid (38%) and lycopene (34%) contents, while PPO activity showed a slight increase in PPO (10%) but a decrease compared to mild heat treatments (50° and 60°C). ".