Antioxidant metabolism in pepper fruit (Research in Context)

Pepper (Capsicum annuum) contains high levels of antioxidants, such as vitamins A and C and flavonoids. However, information on the role of these beneficial compounds in the physiology of pepper fruit remains scarce. Recent studies have shown that antioxidants in ripe pepper fruit play a key role in responses to temperature changes, and the redox state at the time of harvest affects the nutritional value for human consumption.

Model of reactive oxygen species (ROS) metabolism in peroxisomes from pepper fruit.
Model of reactive oxygen species (ROS) metabolism in peroxisomes from pepper fruit. Full details in Palma et al.

Palma et al. examine the role of antioxidant metabolism of pepper fruit during ripening and in the response to low temperature, paying particular attention to ascorbate, NADPH and the superoxide dismutase enzymatic system. They find that important changes occur at a subcellular level during ripening, particularly in chloroplasts, mitochondria and peroxisomes, but proteomic analysis of the latter two organelles show no changes between the antioxidant metabolism from immature (green) to ripe (red) fruits. Investigation of molecular and enzymatic antioxidants from cell compartments is a useful tool, particularly in the context of expanding the shelf-life of fruit after harvest and in maintaining their nutritional value.

This article appears in the special issue ROS and NO Reactions in Plants.