Potenziale antiossidante di mele biodinamiche e convenzionali e variazioni nel corso della conservazione

In the recent years, much attention is being paid to organic and biodynamic cultivations as alternative forms of agriculture to produce high-quality food in an environmentally compatible manner. According to EC Regulation, organic plant products are grown without the use of chemical-synthetic pesticides and largely without the addition of readily soluble mineral fertilisers, with extensive soil tillage and specific soil fertilization practices. Even more rigid rules are applied in biodynamic than in organic cultivations. In the frame of a national (MIPA) project we tried to identify endogenous compounds of possible use in the characterization of organic plant products. In this study, we compared the concentration of ascorbic acid, citric acid, total phenolic compounds and the activity of polyphenoloxidase in conventional and biodynamic apples (cv. Golden) provided by the Istituto Sperimentale di Ricerca Agraria, Laimburg (Bolzano). 2-Thiobarbituric acid-reactive substances (TBA-RS), compounds related to oxidative processes, were also determined. These parameters were reassayed after storage of the fruits at 1.5°C up to six months. The results strongly suggest that metabolic changes occurred as a consequence of the biodynamic cultivation practice, resulting in an increase in the antioxidant potential of the plant. These changes may exert protection against oxidative damage during storage.