Storage Effects on the Physicochemical Properties, Phytochemical Composition, and Sugars in Red-Fleshed Cultivars, ‘Rubycot’ Plumcot, and ‘Queen Garnet’ Plum

Abstract

Domestic storage conditions can have a significant impact on the composition of phytochemicals and sugars in stone fruits. This study aimed to evaluate the effect of two domestic storage temperatures (4 and 23 °C) on the physicochemical properties, phytochemical composition, and sugars of ‘Rubycot’ (RC) plumcot, a novel stone fruit variety, and ‘Queen Garnet’ (QG) plum. Initially, RC had a lower total anthocyanin concentration (TAC) than QG, but TAC in RC increased significantly (p < 0.05) during storage, peaking at +95% after 7 days at 23 °C, while QG reached +60% after 14 days. At 4 °C, TAC increased for both varieties (RC +30%, QG +27%). RC had a higher initial total phenolic content (TPC), which also increased for both fruits. QG had a significantly higher initial total quercetin concentration (TQC), increasing by 40% (p < 0.05) at 23 °C. The initial total carotenoid concentration in QG was higher than that in RC, but after 10 days at 23 °C, RC had a higher carotenoid concentration than QG. Both varieties showed similar sugar profiles, with QG starting higher but decreasing over time at both storage temperatures. Results from this study showed that ambient storage significantly increases total anthocyanins, total quercetins, and TPC in RC and QG. However, it is important to evaluate the textural and sensory properties of stored RC and QG in terms of consumer acceptability of the stored fruits.