Fruit quality involves a series of traits including size, texture, flavor and aroma, which are 32 genotype-dependent but can be altered by pre-harvest factors, agronomical practices and 33 post-harvest treatments. Thinning is a classical agronomic practice that modifies source34 sink balance, resulting in larger fruits and altered total soluble-solids (TSS) content. Stone 35 fruits designated for overseas markets should be cold-stored to extend fruit shelf-life and 36 reach their destination. Although cold storage is effective it leads to metabolic 37 reconfiguration, which could affect organoleptic properties. In this work, we evaluated ‘Red 38 Pearl’ nectarine fruits harvested from trees with differential thinning treatments over two 39 consecutive growing seasons. Physiological and metabolic data analyses were performed 40 during different postharvest conditions to identify the effect of thinning and season on final 41 fruit properties. The results obtained showed that thinning of ‘Red Pearl’ nectarine trees 42 leads to fruits with improved size and TSS content, and thinning advances the harvests 43 with different intensities depending on the growing season. When thinning was performed 44 at early developmental stages, the effects of thinning were more favorable, leading to an 45 improved sugar/acid ratio that was mainly due to improved sugar content. It was also 46 observed that a general increase in quinic acid content when fruits are cold stored 47 independently of season and thinning treatment was likely related to chilling injury. We 48 showed that although sugar and organic acid contents are genetically determined, pre49 and post-harvest conditions and differential thinning can drastically affect their contents, 50 altering final fruit organoleptic perception. 51 52 Key words 53 Prunus persica, cold storage, postharvest, peach46