Variation of biochemical and antioxidant activity with respect to the part of Capsicum annuum fruit from Tunisian autochthonous cultivars

Pepper is a good source of bioactive compounds and has an important role in the Mediterranean diet as a health promoting food. Thus, this study was carried out with the aim to evaluate differences among fruit parts (pericarp, placenta and seed) in terms of total phenols and flavonoids content, capsaicin content and antioxidant activity in eleven cultivars grown in Tunisia. The antioxidant activity of the samples was measured by both 2,2diphenyl-1-picrylhydrazyl (DPPH) and ferrous reducing antioxidant power (FRAP) assays. Overall, significant differences were observed in relation to the cultivar and fruit parts. In particular, the pericarp exhibited the highest levels of total phenols (6.82 +/- 0.39 mg GAEg(-1) DW) and flavonoids (0.46 +/- 0.03 mg NAEg(-1)), whereas placenta showed the highest content of capsaicin (0.83 +/- 0.07 mg(-1) DW). Total phenols and flavonoids appeared to be the main contributors to the antioxidant activity in the pericarp, while capsaicin mainly contributed to the antioxidant capacity in the placenta. The fruit parts of Tunisian pepper cultivars demonstrated a high diversity of bioactive compounds, that should be exploited for food and pharmaceutical applications, meantime our data also encouraged the consumption of placenta and seeds. Finally, such wide variability among Tunisian pepper cultivars might represent a good tool for further breeding programs.