STUDY OF THE RELATION BETWEEN PEACH RIPENING AND PHENOLIC COMPOUNDS

Rising interest in beneficial health properties of fruit and achievement of the best organoleptic qualities in relation to ripening times, led to focus the attention on peach fruits. Phenolic composition in peach fruit changes during ripening process and influences the final quality. A collection field has been set-up, where different peach genotypes of interest (melting flesh=MF and not melting flesh=NMF) have been grown. After pit hardening, fruits growth and ripening have been monitored, the latter using a non-destructive portable instrument (DA-meter) providing an index linked with the chlorophyll degradation thus related to ripening degree. Classical destructive quality analysis was also carried out during the sampling. The general aim of this research has been to investigate about the possible relation between phenolic compounds and ripening stages in peach fruit. Differences in the amount of phenolic compounds in flesh and peel during the maturation process have been evaluated. Quantification of the most important phenolic compounds was obtained using a LC-MS/MS system. Results reported that the DA index (IDA) decreased reaching the ripening stage, in both peach genotypes (MF and NMF) and it also showed a relationship with ethylene production of fruits, demonstrating a good reliability of the instrument. Preliminary results showed that from ‘Oro A’s phenolic analysis in pre-climac- teric stage, the amount of quercetin 3-rutinoside and cyanidin 3-glucoside in the peel resulted substantially higher than in the flesh. Among the main flavan-3-ols, catechin resulted in higher content compared to epicatechin, in agreement with previous works. Among hydroxycinnamic acids, chlorogenic acid resulted in higher amount than neo- chlorogenic as reported by other studies.