A preliminary transcriptomic approach to elucidate post harvest ripening of plum fruit

The aim of the present study was to dissect common and/or diverse mechanisms regulating plum (Prunus salicina) fruit ripening in genotypes characterized by different patterns of ethylene production. Fruit of an ethylenesuppressed cultivar ('Shiro') and a cultivar characterized by the typical increase of ethylene production during fruit ripening ('Santa Rosa') were harvested at commercial maturity stage and allowed to further ripen at room temperature (23°C) up to 4 days. While non-detectable amounts of ethylene were recorded in 'Shiro' fruit, a typical climacteric behavior was observed in 'Santa Rosa' plums. For comparative purposes, the peach microarray μPEACH 1.0 containing 4,806 oligonucleotides corresponding to an equal number of genes expressed in peach fruit was employed for transcript profiling during postharvest ripening of both cultivars. Intriguingly, transcript levels of genes involved in ethylene biosynthesis, primarily 1-aminocyclopropane-1-carboxylate synthase, appeared to increase during the progress of 'Shiro' fruit ripening, following the same pattern as in 'Santa Rosa' plums. These data suggest that an induction of the ethylene biosynthetic pathway is present also in plum cultivars in which the burst of ethylene is not detectable. Expression levels of other genes implicated in auxin metabolism, antioxidant system and stress response followed the same pattern in both cultivars. Overall, this preliminary transcriptomic approach tried to elucidate the flow of events that accompany postharvest ripening of plum cultivars with diverse properties in relation to ethylene evolutio

Comparative transcriptomic analysis of plum fruit treated with 1-MCP

Microarray technology has allowed the large scale transcriptomic analysis of fruit ripening. The μPEACH1.0 microarray containing 4,806 probes corresponding to genes expressed in peach fruit tissues has been used in a heterologous fashion in two studies of plums ripening behavior. Gene expression of different cultivars of plums treated with the ethylene antagonist, 1-methylcyclopropene (1-MCP) and stored for short periods at room temperature or for longer periods of cold storage was examined. In the first study, mature fruit of a suppressed ethylene climacteric cultivar 'Shiro' and a cultivar characterized by a typical increase of ethylene production during ripening ('Santa Rosa') were harvested and incubated for 24h in air (control) or 1-MCP and allowed to ripen at room temperature. Different levels of transcripts of genes implicated in cell wall metabolism, hormone (ethylene and auxin) regulation, stress and defense, and in the transcription/translation machinery, as well as others involved with ripening were identified. In the second study, the effects of 1-MCP on gene expression in relation to the development of chilling injury (CI) in the climacteric cultivars 'Ruby Red' (RR) and 'October Sun' (OS) and 'Zee Lady' peaches (ZP) were analyzed. The fruit were treated for 24h at room temperature with 1-MCP prior to storage at 0°C. For RR, there was no significant effect of 1-MCP on the level of CI symptoms, while 1-MCP significantly reduced CI symptoms in OS fruit and an increase of CI in treated ZP fruit. Microarray analysis showed that immediately following treatment, 186, 134 and 56 genes were differentially expressed between the control and 1-MCP-treated fruit of these cultivars, respectively: after 4 weeks cold storage, 311, 52 and 224 genes for RR, OS and ZP, respectively, were differentially expressed between control and treated fruit. Thus, for OS, the number of differentially expressed genes reduced during storage while the number increased in RR and ZP. Comparisons of the data suggest that the transcript profile is altered by 1-MCP more in plums than peaches. These studies, carried out within an international collaborative network, will increase our understanding of the regulation of pathways involved in plum fruit ripening and in metabolic processes related to storage and shelf lif

1H NMR Metabolic Fingerprinting to Probe Temporal Postharvest Changes on Qualitative Attributes and Phytochemical Profile of Sweet Cherry Fruit

Sweet cherry fruits (Prunus avium cvs. ‘Canada Giant’, ‘Ferrovia’) were harvested at commercial maturity stage and analyzed at harvest and after maintenance at room temperature (storage at ~ 20°C, shelf life) for 1, 2, 4, 6 and 8 days, respectively. Fruit were initially analyzed for respiration rate, qualitative attributes and textural properties: ‘Canada Giant’ fruit were characterized by higher weight losses and stem browning index, being more intense over the late stages of shelf life period; meanwhile ‘Ferrovia’ possessed appreciably better performance even after extended shelf life period. A gradual decrease of respiration rate was monitored in both cultivars, culminated after 8 days at 20°C. The sweet cherry fruit nutraceutical profile was monitored using an array of instrumental techniques (spectrophotometric assays, HPLC, 1H-NMR). Fruit antioxidant capacity was enhanced with the progress of shelf life period, concomitant with the increased levels of total anthocyanin and of phenolic compounds. ‘Ferrovia’ fruit presented higher contents of neochlorogenic acid and p-coumarolquinic acid throughout the shelf life period. We further developed an 1H-NMR method that allows the study of primary and secondary metabolites in a single running, without previous separation and isolation procedures. Diagnostic peaks were located in the aliphatic region for sugars and organic acids, in the aromatic region for phenolic compounds and at 8.2 to 8.6 ppm for anthocyanins. This NMR-based methodology provides a unifying tool for quantitative and qualitative characterization of metabolite changes of sweet cherry fruits; it is also expected to be further exploited for monitoring temporal changes in other fleshy fruits

Nutritional Quality of Fruits and Vegetables

Horticultural crops are some of the main components of a healthy diet. The constituents obtained by the human body from fruits and vegetables include water, carbohydrates, fats, proteins, fi ber, minerals, organic acids, pigments, vitamins and antioxidants, among others. Fruits and vegetables, especially, are a good source of fi ber, selected minerals, vitamins and antioxidants. Most fruits and vegetables are available almost year-round in a wide variety and they not only taste good, but they also have favorable attributes of texture, color, fl avor and ease of use. They can be fresh, cooked, hot or cold, canned, pickled, frozen or dried. Fruits and vegetables are consumed at all times, and due to their convenient size; they are an excellent between-meal snack. They are relatively low in calories and fat (avocado and olives being the exceptions), they have no cholesterol, they are rich in carbohydrates and fi ber, they contain vitamin C and carotene, and some are a good source of vitamin B 6 . Fruits and vegetables are relatively low in sodium and high in potassium. Ascorbic acid in fruits and vegetables enhances the bioavailability of iron in the diet. Because of all these characteristics, fruits and vegetables have a unique role in a healthy diet. A growing body of research has shown that fruit and vegetable consumption is associated with reduced risk of major diseases, and possibly delayed onset of age-related disorders, promoting good health. However, in many cases fruit and vegetable consumption is still below the dietary guideline goal of consuming 5–10 servings each day. The nutritional value of fruits and vegetables depends on their composition, which shows a wide range of variation depending on the species, cultivar and maturity stage. The composition of fruits and vegetables includes a great number of metabolites however, it could be predicted that no single commodity might be rich in all these constituents. This chapter describes the general characteristics of the components of fruits and vegetables, related to their benefi ts as food sources.Facultad de Ciencias Agrarias y Forestale

Physiological and proteomic approaches to address the active role of ozone in kiwifruit post-harvest ripening

Post-harvest ozone application has recently been shown to inhibit the onset of senescence symptoms on fleshy fruit and vegetables; however, the exact mechanism of action is yet unknown. To characterize the impact of ozone on the post-harvest performance of kiwifruit (Actinidia deliciosa cv. ‘Hayward’), fruits were cold stored (0 °C, 95% relative humidity) in a commercial ethylene-free room for 1, 3, or 5 months in the absence (control) or presence of ozone (0.3 μl l−1) and subsequently were allowed to ripen at a higher temperature (20 °C), herein defined as the shelf-life period, for up to 12 days. Ozone blocked ethylene production, delayed ripening, and stimulated antioxidant and anti-radical activities of fruits. Proteomic analysis using 1D-SDS-PAGE and mass spectrometry identified 102 kiwifruit proteins during ripening, which are mainly involved in energy, protein metabolism, defence, and cell structure. Ripening induced protein carbonylation in kiwifruit but this effect was depressed by ozone. A set of candidate kiwifruit proteins that are sensitive to carbonylation was also discovered. Overall, the present data indicate that ozone improved kiwifruit post-harvest behaviour, thus providing a first step towards understanding the active role of this molecule in fruit ripening

Exploring the Phytochemical Content and the Antioxidant Potential of Citrus Fruits Grown in Cyprus

The physicochemical and phytochemical profile as well as the antioxidant properties of the most important Citrus fruits grown in Cyprus [orange (Citrus sinensis, cv. ‘Valencia’), grapefruit (Citrus paradisi, cvs. ‘White Marsh’, ‘Star Ruby’, ‘Rio Red’) and an interspecific hybrid (Citrus reticulata x Citrus sinensis, cv. ‘Mandora’)] were determined. ‘Valencia’ fruit exhibited the highest phenolic, flavonoid and ascorbic acid content, as well as a higher antioxidant potency, followed by ‘Mandora’ fruit and the three grapefruit cultivars. HPLC indicated significant diversity on flavanones among the examined fruits, while LC–MS analysis revealed the presence of hydroxycinnamic acid derivatives, polymethoxyflavones and a furocoumarin. Overall, this study provides supporting evidence for the superiority of ‘Valencia’ orange fruit as an excellent source of bioactive compounds. In addition, to the best of our knowledge, this is the first study thoroughly describing the phytochemical profile of ‘Mandora’ fruit, an interspecific hybrid cultivated in Cyprus

The effect of postharvest ripening on strawberry bioactive composition and antioxidant potential

Background: The aim of the present work was to evaluate the phytochemical profile and the antioxidant activity of strawberry fruit (cv. Camarosa) upon postharvest ripening at room temperature (20 °C) and to correlate them with qualitative attributes. Results: 'Camarosa' fruit retained an appreciable postharvest performance for up to 1 day shelf life; thereafter substantial quality deterioration was observed. An increased phenolic content, mainly attributed to hydroxycinnamic acids, flavonols and anthocyanins, was monitored after 3 days maintenance at 20 °C. The chromatographic fingerprint of athocyanins showed that pelargonidin-3-glucoside was the major anthocyanin, which increased with the increase of shelf life period, while cyanidin-3-glucoside and pelargonidin-3-rutinoside were found at lower concentrations. The potent radical scavenging activity, evaluated with four in vitro assays, showed a higher antioxidant capacity after 3 and 1 days of shelf life. In addition, the antioxidant effect of strawberry fruit extracts on lipid substrates and on an emulsion system showed a significant inhibition in the formation of conjugated diene hyperoxides. Interestingly, no direct correlation between the phytochemical profile and the quality attributes exist. Conclusion: 'Camarosa' fruit had acceptable quality attributes for fresh consumption and at the same time a high phytochemical content up to 1 day shelf life. The over-ripe fruit continued to be an excellent reservoir of natural antioxidants, pointing to its potential use as food antioxidant and nutritional supplement