Carotenoids, Phenolic Profile, Mineral Content and Antioxidant Properties in Flesh and Peel of Prunus persica Fruits during Two Maturation Stages

Abstract

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.

Stone Fruit as Biofactories of Phytochemicals With Potential Roles in Human Nutrition and Health

“…In peaches, carotenoids are responsible for the yellow color of the pulp, and therefore, their concentration is low in white pulp fruits ( Gil et al., 2002 ). Peaches contain anthocyanins (cyanidin-3-glucoside and cyanidin-3-rutinoside), flavan-3-ols (catechin—the main monomeric flavan-3-ol-, epicatechin, epigallocatechin, and procyanidins), flavonols (quercetin-3-O-rutinoside or rutin, quercetin-3-glucoside, quercetin-3-galactoside, kaempferol-3-rutinoside), hydroxycinnamic acids (chlorogenic and neoclorogenic acids) ( Campbell and Padilla-Zakour, 2013 ; Dabbou et al., 2017 ), and the main carotenoids include β -carotene and xanthophylls (mono- or di-hydroxylated carotenoids), zeaxanthin, β -cryptoxanthin and violaxanthin ( Tomas-Barberan et al., 2001 ; Campbell and Padilla-Zakour, 2013 ; Dabbou et al., 2017 ), and lutein ( Oliveira et al., 2016 ). Amounts of some of the most representative phytochemicals present in the pulp of peach of different cultivars at commercial maturity are shown in Table 1 .…”

Carotenoid cleavage in chromoplasts of white and yellow‐fleshed peach varieties

“…In fact, in the specific case of Redhaven , β‐carotene accounted for only 5% of total carotenoids in mature fruits (and β‐cryptoxanthin for about 7%), being tetraterpene content mostly due to other xanthophylls . In many other yellow genotypes, on the contrary, β‐carotene exceeds 60%, and β‐carotene and β‐cryptoxanthin together account for up to 90% of total carotenoids . If confirmed, this substrate specificity would imply that peach CCD4 is not involved in determining the final concentration of β‐carotene, which should depend on the activity of other enzyme(s).…”

“…Alternatively, peach CCD4 might recognize neither β‐carotene nor β‐apo‐8′‐carotenal as substrates. This would have significant implications, since β‐carotene is one of the two main carotenoids (the other one being β‐cryptoxanthin, hydroxy‐β‐carotene) that are present in fruit flesh of yellow peach varieties . In fact, in the specific case of Redhaven , β‐carotene accounted for only 5% of total carotenoids in mature fruits (and β‐cryptoxanthin for about 7%), being tetraterpene content mostly due to other xanthophylls .…”

“…15 In many other yellow genotypes, on the contrary, -carotene exceeds 60%, and -carotene and -cryptoxanthin together account for up to 90% of total carotenoids. 33,34 If confirmed, this substrate specificity would imply that peach CCD4 is not involved in determining the final concentration of -carotene, which should depend on the activity of other enzyme(s). A third possibility is that peach CCD4 might use -carotene and/or -apo-8 ′ -carotenal as substrates, but with low efficiency, or that it uses them efficiently, but it is present in the cell at very low levels.…”

“…This would have significant implications, since -carotene is one of the two main carotenoids (the other one being -cryptoxanthin, hydroxy--carotene) that are present in fruit flesh of yellow peach varieties. 33,34 In fact, in the specific case of Redhaven, -carotene accounted for only 5% of total carotenoids in mature fruits (and -cryptoxanthin for about 7%), being tetraterpene content mostly due to other xanthophylls. 15 In many other yellow genotypes, on the contrary, -carotene exceeds 60%, and -carotene and -cryptoxanthin together account for up to 90% of total carotenoids.…”