Influence of agricultural practices on the quality of sweet pepper fruits as affected by the maturity stage

Background: Peppers are popular vegetables because of their colour, taste and nutritional value. The levels of vitamin C, carotenoids and phenolic compounds in peppers and other vegetables depend on several factors, including cultivar, agricultural practice and maturity stage. Results: In this study the effects of maturation and type of agricultural practice (organic or conventional) on the ascorbic acid, total carotenoid and total phenolic contents and colour parameters of sweet peppers (Capsicum annuum cv. Almuden) grown in a controlled greenhouse were determined. Levels of vitamin C, phenolic compounds and carotenoids increased during ripening, with red sweet peppers having higher contents of these bioactive compounds. Moreover, peppers grown under organic culture had higher vitamin C, phenolic and carotenoid levels than those grown under conventional culture. With respect to colour parameters, organic red peppers had higher values of L*, a*, b*, C* and H-ab than conventional red peppers, giving them a higher intensity of red colour. Conclusion: Thus organic farming had a positive effect on the nutritional content of peppers, increasing the vitamin C activity and the level of phenolic compounds, both implicated in the antioxidant activity of vegetables, and the content of carotenoids, implicated in the colour variance observed in pepper fruits. (C) 2007 Society of Chemical Industry