Antioxidant accumulation in different pepper organs

Pepper (Capsicum annuum L.) is an important crop not only for the economic point of view, but also for the nutritional value of its fruits which are a source of antioxidants such as ascorbic acid, polyphenols, carotenoids, and chlorophylls. These, reduce the risk of onset of diseases such as atherosclerosis, some cancers and degenerative and cardiovascular disease. Antioxidants vary according to the genotype, developmental stage and environmental conditions. The aim of this study is to evaluate during ripening the accumulation of antioxidant metabolites in different pepper ecotypes and varieties which differ in the fruit colour and shape. Pepper seeds were provided by SemiOrto Sementi (http://www.semiorto.com) and plant germoplasm Regione Campania. The experiments were carried out in a greenhouse. Antioxidants in leaves were evaluated at vegetative stage, and in fruits at the stages: immature (IG); mature green (MG); turning (T), and ripe (R). In leaves, all analyzed antioxidants varied according to the genotypes. In general at higher polyphenol contents corresponded lower total ascorbic acid. Among the numerous genotypes, Corno di Capra Giallo showed the highest accumulations of total ascorbic acid, licopene, ß‐carotene and flavonoids and had also a good amount of total polyphenols and chlorophylls. In fruits, generally total ascorbic acid increased along ripening, and at the ripe the highest values was reached in Puparulillo and Papecchia and the lowest in Nocera Giallo. Instead, in the ecotype Rogianiello the highest total ascorbic acid was at MG stage. Polyphenols generally showed a minimum at MG and in the other stages was variable among ecotypes. This investigation could be useful as preliminary study for the pepper resistance to abiotic and biotic stresses, that are know to be controlled by antioxidants, and to evaluate nutraceutical quality of peppers that in Mediterranean diet are consumed at any ripening stage.