Influence of the forcing process on some qualitative aspects in radicchio “Rosso di Treviso tardivo” (Cichorium intybus L., group rubifolium). 1. Nitrate, nitrite and organic nitrogen

Radicchio “Rosso di Treviso tardivo” (Cichorium intybus L., group rubifolium), a typical vegetable of north-eastern Italy, has gained increasing commercial interest in recent years due to its particular shape and culinary features. These properties are obtained by a forcing process that could affect nitrate and dangerous nitrite contents in the edible product. The experiment was conducted in Veneto (north-eastern Italy, 45°36’N; 12°10’E) with plants grown in a loamy soil and analyzed at harvest and during the forcing process (0-10 and 20 forcing days-FD). Results showed that nitrate and nitrite contents in edible portions never exceed the most restrictive EU limits. A continuous reduction in NO3 content was observed during the forcing process, while NO2 showed a peak at 10 FD. Organic N significantly increased during the forcing process due to NO2 reduction. From a nutritional point of view these results further demonstrate that this type of radicchio is a healthy vegetable for the consumers.