Nutritional value of tomatoes (Solanum lycopersicum L.) grown in greenhouse by different agronomic techniques

The relevance of agronomic practices on the nutritional quality greenhouse-grown tomatoes has been recognized. We investigated the influence of (1) cultivar: two local (Pera-Girona and Montserrat) and one commercial (Caramba) varieties; (2) nitrogen dose in nutrient solution (low vs. standard N dose); (3) treatment for plant disease control (sulfur vs. Milsana (R)) and (4) ripeness (orange vs. full-red color) on levels of carotenoids, phenolic compounds, ascorbic acid and minerals of fruits. Carotenoids and ascorbate were mainly influenced by variety and ripening stage, while N dose slightly affected minerals in fruits; treatments,against plant diseases exerted only negligible effects on measured compounds. Local tomato varieties appear more promising as food source of carotenoids, mainly lycopene, and of hydroxycinnamates, such as 5-caffeoylquinic acid and caffeoylquinic derivatives, than commercial variety (total carotenoids: 67.43 mg kg(-1) fw vs. 56.34 mg kg(-1) fw of Pera-Girona vs. Caramba and total hydroxycinnamates: 90.87 mg kg(-1) fw vs. 37.90 mg kg(-1) fw of Montserrat vs. Caramba, at full-red color). Tomato variety and harvest maturity of fruit were the main factors affecting nutritional value of tomatoes, while Milsana (R) treatment did not result in evident nutritional benefits. However, the use of this elicitor might be appropriate considering the increasing environmentally friendly attitudes of consumers. (C) 2013 Elsevier Inc. All rights reserved.