Influence of variety and storage on the polyphenol composition of apple flesh

Apple is among the most consumed fruits worldwide. It is available on the market for the whole year being a major source of dietary polyphenols. Several studies suggested that apple polyphenols could play a role in prevention of degenarative diseases. The action of these compounds has been partially ascribed to their antioxidative ability, and fruit antioxidants profile is influenced by apple variety and by the postharvest storage. In this work, the polyphenols composition of the flesh of four apple varieties cultivated in southern Italy were investigated by HPLC, and a flow injection MS/MS procedure to quantify cholorogenic acid and catechins was set up. Phenolic composition and the radical scavenging activity were monitored during a postharvest storage of four months. The quantification by flow injection procedure gives results comparable to those obtained by HPLC, and the increase of the antioxidant activity during storage correlated with an increase of the concentration of catechin and phloridzin. This trend is particularly evident for the variety "Annurca" which is a typical product cultivated in the area around Naples. The genetic characteristics of the Annurca variety together with the anticipated harvest time and the peculiar postharvest conditions are likely responsible for this increase of the antioxidant activity.