Bioactive compounds and antioxidant activity of hot pepper fruits at different stages of growth and ripening

Abstract

The evolution of some bioactive compounds and antioxidant activity has been investigated during fruit growth and ripening of five pepper cultivars: ‘Dracula’, ’Pintea’, ‘Pepperone’, ‘Bulgarian carrot’ (C. annuum) and ‘Christmas bell’ (C. baccatum var. pendulum). High-performance liquid chromatography was used to quantify the content of capsaicin in the fruit in order to determine the pungency level of analyzed peppers. Pepper fruits were collected at five stages of growth and ripening. Dry matter, soluble solids, ascorbic acid, total phenolics, including total flavonoids, capsaicin content and antioxidant activity were determined at each stage. There were major differences among the cultivars in the accumulation of the bioactive compounds in the fruit during their growth and ripening, although the quantitative accumulation pathway of various components had a similar trend during phenophases. Antioxidant activity and ascorbic acid content increased during growth and ripening of hot peppers, the highest levels being found in the last stage of ripening. The pattern of variation of total flavonoid content was cultivar dependent. In most cultivars, an important increase of the total phenolic and total flavonoid content was observed in the last stage of ripening. Capsaicin content recorded a maximum level in F3 or F4 depending on cultivar, and decreased afterwards until the complete ripening of the pepper fruits. ‘Dracula’ cultivar was classified as “non-pungent” (fruits are not spicy) while ‘Pintea’ was classified as “highly pungent”, the other analyzed cultivars having an average level of pungency.