Analysis of vitamin C content of fruits from five pepper varieties showing different pungency levels and antimicrobial potentiality of capsaicin

In this work, the nutritional properties and antimicrobial activity of five pepper varieties, including dulce italiano (bell pepper), boiro (a Padron-type pepper), green jalapeño, red chilli, and habanero, have been investigated. The dry matter provided by each of these varieties was analyzed, and their caloric content were withdrawn from searches in databases. Thus, it was found the following caloric contents: Habanero and red chilli provided 40 kcal/100 g; jalapeño green, 29 kcal/100 g; dulce italiano, 23 kcal/100 g; and boiro (padrón), 21 kcal/100 g. On the other hand, an easy and simple method was set up to determine vitamin C (ascorbic acid, ascorbate) in crops, using lugol and starch. The data provided by the application of this method indicated that red chili was the variety with the highest vitamin C content, and boiro the one with the lowest. The antimicrobial activity of both crude extracts from pepper fruits and pure capsaicin was probed against five bacterial species: Escherichia coli, Bacillus subtilis, Xanthomonas campestris, Dickeya dadantii and Ralstonia solanacearum. Solid (Petri dishes with agar) and liquid media were used for the assays. Our data indicated that capsaicin is able to inhibit the growth of B. subtilis, but not that of E. coli, perhaps this latter case due to the great adaptation of this species to environmental conditions.Peer reviewe