Phenolic compounds and carotenoids amounts on guava epicarp injury, 'girdling'

Abstract

Guava epicarp injuries, popularly known as girdling, have been concerned technicians and producers due to misunderstand about their causes. The objective of this study was to analyze the amounts of phenolic compounds and carotenoids present on guava epicarp region affected by injury (girdling) in order to characterize chemically those regions. Concentrations of phenolic compounds (tannins, flavones/ flavonols, anthocyanins and total phenolic compounds) and carotenoids were analyzed on tissue from unripe and ripe guava injured and non-injured epicarp fruits (Psidium guajava cv. Paluma). The experimental design was randomized, and were established six treatments: epicarp from ripe fruit without injury in the lower (FMSI) and upper region (FMSS) of the fruit, unriped fruit without injury (lower - FVSI - and upper region - FVSS), injured unriped fruit with injury (lower - FVCI - and upper region - FVCS). Higher concentrations of phenolic compounds, carotenoids of tannins, were found on tissues of unripe fruit epicarp with girdling when compared with health epicarps. Results showed the participation of phenolics compounds (tannins) and carotenoids as possible substances that characterized the injury formation. Although phenolic compounds and carotenoids have antioxidant properties and are often related as antioxidant defenses, the causes of girdling of guava fruits are still unknown.