Metabolomic profiling and sensorial quality of 'Golden Delicious', 'Liberty', 'Santana', and 'Topaz' apples grown using organic and integrated production systems

Apple quality was investigated in the scab-resistant ‘Liberty’, ‘Santana’, and ‘Topaz’ cultivars and the scab-susceptible ‘Golden Delicious’ cultivar. Trees subjected to the same crop load were cultivated using either an organic (ORG) or an integrated production (IP) system. Physicochemical properties, phenolic content, and sensorial quality of fruit from both systems were compared. There were no significant differences in fruit mass, starch, and total soluble solid content (the latter was higher in ORG ‘Liberty’) between ORG and IP fruit, whereas significantly higher flesh firmness was found in ORG fruit (except no difference in ‘Golden Delicious’). Significantly higher total phenolic content in ORG fruit was found in ‘Golden Delicious’, whereas differences in other cultivars were not significant. Targeted metabolomic profiling of multiple classes of phenolics confirmed the impact of the production system on the ‘Golden Delicious’ phenolic profile as higher levels of 4-hydroxybenzoic acid, neo- and chlorogenic acids, phloridzin, procyanidin B2+B4, -3-O-glucoside and -3-O-galactoside of quercetin, kaempferol-3-O-rutinoside, and rutin being found in ORG fruit. The results obtained suggested that scab resistance influenced the phenolic biosynthesis in relation to the agricultural system. Sensorial evaluation indicated significantly better flavor (except for ‘Topaz’) and better appearance of IP fruit