Carotenoids and phenolic profile, antioxidant activity as well as concentrations of selected macronutrients (K, N, Mg, Ca and Na) and micronutrients (Zn, Cu and Mn) in flesh and peel of peach fruit were recorded at two harvest dates. Predominant mineral was potassium, followed by calcium, magnesium and sodium. The concentration of most micronutrients was greater in the peel than in the flesh especially in early season. The concentration of most elements in flesh and peel decreased during fruit maturation. Total carotenoids content varied with respect to the cultivar. β-cryptoxanthin and β-carotene were the major carotenoids in both tissues and flesh contain the lowest amounts. Neochlorogenic acid, chlorogenic acid, catechin, epicatechin, gallic acid, rutin, quercetin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, were detected in both peel and flesh, with chlorogenic acid and catechin being the predominant components. Peel extracts showed markedly higher antioxidant activities, when estimated by ABTS or DPPH assays, than the flesh counterparts, consistent with the observed higher phenolic content. Overall, total phenolics levels increased at full ripening stage in both peel and flesh. The results found herein provide important data on carotenoids, phenolic and macro- and micronutrient changes during fruit growth, and emphases peach fruit as a potential functional food.

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Introduction. Drought can affect the qualitative and nutritional attributes of plum (Prunus salicina L.). The aim of this work was to study the effect of regulated deficit irrigation (RDI) on the quality of plum fruits. Materials and methods. Experiments were conducted during two consecutive seasons (2011-2012) with three cultivars ('Black Diamond', 'Black Gold' and 'Black Star') recently introduced in the region of Regueb (center of Tunisia) characterized by a semi-arid climate. During the fruit growth period, treated trees (RDI 50) received 50% of the irrigation water provided to the control (CI) for three months. Results and discussion. Water restriction reduced the diameter and weight of the fruit though the extent depended on the cultivar. However, other measures of fruit quality were improved for all cultivars with an increase of fruit firmness, pH, soluble solids and sucrose content, and a decrease of total acidity. Additionally, 'Black Diamond' fruit from treated trees had high level of total phenolics and flavonoids. Conclusion. Regulated deficit irrigation may save water in semi-arid regions and improve fruit quality with only moderate impact on productivity.

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