Seasonal variability of phytochemical composition of new red-fleshed apple varieties compared with traditional and new white-fleshed varieties

The main objective of this study was to evaluate the impact of the season on the apple phytochemical composition (phenolic compounds, triterpenes, and organic and ascorbic acids). For this proposal, four red-fleshed and five white-fleshed apple varieties from two consecutive seasons (2015 and 2016) were studied. A significant interaction with the season in some compounds was observed. The total phenolic content in the apple flesh from 2015 was higher than that from 2016 probably related with the lower rainfall during the harvest period in 2015 that could have favored hydric stress in the apple trees. The impact of the season on the apple skin was different. The 2016 season was characterized by higher maximum and minimum temperatures resulting in a higher content of flavonols, triterpenes, and organic acids. Anthocyanin concentration in both the flesh and skin of the red-fleshed apples showed no clear relationship to the season, and each variety showed an individual pattern.This study was supported by the Spanish Ministry of Economy and Competitiveness through the AGL2016-76943-C2-1-R project (cofunded by the State Research Agency (AEI) and the European Regional Development Fund ERDF); and by the Spanish Ministry of Education, Culture and Sport through the “Formación Profesorado Universitario” grant awarded to D.B.-C. (FPU014/02902). In addition, L.B. acknowledges support from the MTM2015-69493-R grant from the Spanish Ministry of Economy and Competitiveness.Peer reviewe