Peach and nectarine have a relatively large variation in the ontree maturity; due to this variability it is essential to apply successive harvests. Maturity at harvest is usually determined based on commercial size and diameter, background color and flesh firmness (Crisosto and Valero, 2008). However, color can be hardly distinguished in some cultivars as an intense blush is developed before the fruit is ripe for harvest, while firmness determination is carried out in a destructive manner, and may vary
indication of the ripening stage. The IAD index has allowed to assess peach ripening stage in the field and during storage . Nevertheless, reports document the relationships among IAD and specific ripening-related changes in a relatively small number of peach and nectarine cultivars. Therefore, it is an emerging need to set non-destructive index thresholds on a cultivar basis.
Peach fruit physiology has been extensively studied both during on-tree maturation and postharvest ripening after harvest or after cold storage. Nevertheless, little is known on the combined effects of postharvest ripening and genotype on the fruit qualitative and antioxidant potency. The objectives of the current study were initially to evaluate the usefulness of non-destructive assessment of ripening related changes on an array of peach and nectarine cultivars and further to determine the genetic variation in antioxidant phenols and dissect potential correlations among the examined parameters.