Dataset on antioxidant metabolites and enzymes activities of freshly harvested sweet cherries (Prunus avium L.) of Campania accessions

In this article, we reported the original data obtained by the study of metabolites and enzymes involved in sweet cherry antioxidant system. We measured hydrogen peroxide (H2O2) and malondialdehyde (MDA), which are indicator of oxidative stress. Moreover, we measured the concentration of reduced and oxidized ascorbate and glutathione that are involved in ROS detoxification together with phenolics, anthocyanins and tocopherols. Among antioxidant enzymes, we analyzed the activities of ascorbate peroxidase (APX; EC 1.11.1.11), and the soluble and bound forms of polyphenol oxidase (PPO; EC 1.10.3.1) and guaiacol peroxidase (POD; EC 1.11.1.7). The data reported in this paper are related to the research article “Metabolic characterization and antioxidant activity in sweet cherry (Prunus avium L.) Campania accessions”, authored by Mirto et al. (2018) [1].


Subject area
Agricultural and biological science More specific subject area

Postharvest physiology
Type of data Tables  How data was  acquired Spectrofluorometric detection (Synergy HT, Biotek), DAD/UV and FLD HPLC detection (HP-1100, Agilent) Data format Raw data statistically analyzed Experimental factors The data concern freshly harvested cherries without any pretreatment

Experimental features
The experimental design included metabolic profiling and enzyme activity analyses Data source location Value of the data The data show the antioxidant metabolites and enzyme activities measured in sweet cherries fruits.
The data highlight the differences among the different sweet cherries Campania accessions. The data are useful to identify the accessions more suitable for long-term storage.

Data
Selecting fruit accessions rich in antioxidant can help delaying fruit senescence and better preserving its characteristics during postharvest. To this aim, we investigated antioxidant metabolites level and antioxidant enzyme activities in forty-three accessions of sweet cherry fruits from Campania region [1].
In Table 1 we reported the concentration of hydrogen peroxide (H 2 O 2 ), as well as malondialdehyde (MDA) of sweet cherry fruit accessions. MDA is considered a useful index of general lipid peroxidation and a biomarker for oxidative stress [2]. In Table 1 reduced and oxidized forms of ascorbate (AsA and DHA) and glutathione (GSH and GSSG) which are indicators of oxidative stress were also presented. A high reduced per oxidized ratio of the two metabolites is essential for ROS scavenging in plant cells [3][4][5]. In Table 2 we showed the concentration of phenolics, anthocynanins and tocopherols, involved in ROS detoxification together with ascorbate and glutathione [3,4].
In Table 3 the activities of enzymes involved in antioxidant system were considered: ascorbate peroxidase (APX; EC 1.11.1.11), and the soluble and bound forms of polyphenol oxidase (PPO; EC 1.10.3.1) and guaiacol peroxidase (POD; EC 1.11.1.7). In particular, POD and PPO, in addition to acting as ROS scavengers, are also responsible for the oxidation of phenolic compounds to quinones, in presence of O 2 (PPO) or H 2 O 2 (POD), and their subsequent, polymerization to melanin. This phenomenon known as enzymatic browning, that occurs during fruit storage [6] negatively affects fruit color, taste, flavor, nutritional value and consistence and causes more than 50% of fruit losses [7]. Table 1 Hydrogen peroxide (H 2 O 2 ), malondialdehyde (MDA), reduced and oxidized ascorbate (AsA and DHA)) and glutathione (GSH and GSSG) contents in sweet cherry fruits. All data are expressed as mg 100 g -1 FW 7 SD (n ¼3).

Experimental design, materials and methods
To identify the accessions which better resist to oxidative stress and, therefore, are more suitable for the long-term storage, sweet cherry fruits of forty-three accessions from Campania region were harvested and collected at commercial maturity, in the regional experimental farm "Improsta", Eboli Campania, Italy (approximately at 14°58′E, 40°33′N). One additional commercial accession (Bigarreaux) and two commercial cultivars (Del Monte and Ferrovia) were used as reference. The data were obtained by biological triplicates, each one constituted by twenty fruits from five plants, analyzed separately. The fleshy part of fruits was cut, frozen in liquid nitrogen, and powdered [8]as soon as the Table 2 Tocopherols, total polyphenols and anthocyanins analysed in sweet cherry fruits. Tocopherols are expressed as mg 100 g -1 FW 7 SD (n ¼3). Total polyphenols and anthocyanins are expressed as µg 100 g -1 FW 7 SD (n ¼ 3).

Accession
Total tocopherols α-tocopherol γ-tocopherol Total polyphenols Anthocianins samples arrived in the laboratory and then stored at -80°C for preserving the antioxidant enzymatic activities and antioxidant metabolite levels.
Reduced and oxidized ascorbate (AsA þ DHA) and reduced and total (reduced plus oxidized) glutathione (GSH) were extracted and evaluated as described in Annunziata et al. [9]. Tocopherols determination was performed by HPLC, modifying the method described by Annunziata et al. [9]. Tocopherols were determined measuring their fluorescence with excitation at 295 nm and emission at 340 nm, and the concentration was determined for comparison with standard curves of pure α-, or γ-tocopherol in the range 0.06-2 mg L -1 . Hydrogen peroxide (H 2 O 2 ) malondialdehyde (MDA) were assayed according to Woodrow et al. [4]. Total phenolics were measured by the Folin-Ciocalteu Table 3 Enzymatic activities measured in analysed sweet cherry fruits. PODs and PPOs activities are expressed as µmol min -1 g -1 FW; APX activity is expressed as nmol min -1 g -1 FW. method of Ainsworth and Gillespie [10]. Anthocyanins were assayed by UV-Visible spectroscopy method of Giusti and Wrolstad [11].