Quality Traits and Nutritional Components of Cherry Tomato in Relation to the Harvesting Period, Storage Duration and Fruit Position in the Truss.

It is well known that the harvesting period and the storage duration have a significant effect on the quality characteristics of cherry tomato fruits. On the other hand, the effect of the fruit position in the truss has not been studied, as well as the relative contribution of each one of these factors on fruit quality. For this purpose, cherry tomato (Genio F1) whole trusses were harvested at the fruit red ripe stage during three periods. At each harvesting period, the first four (at the base of the truss) and the last four (at the top) fruits from each truss that was previously trimmed to 10 fruits, were stored at 12 °C for 0, 4 and 10 days. At the end of each storage duration, the external color, firmness, antioxidant capacity, pH and titratable acidity, as well as dry matter, soluble solid, total soluble phenol, lycopene, total carotenoid and ß-carotene content, were determined. Analysis of variance (ANOVA) indicated that the harvesting period had the most significant effect on skin color parameters L * and C * and ß-carotene, as well as on antioxidant capacity, total soluble phenols, dry matter and total soluble solids, while it also had an appreciable effect on titratable acidity. The storage duration had a dominant effect on firmness, total carotenoids and lycopene, while it had an appreciable effect on skin color parameter L * as well. On the other hand, the fruit position in the truss exerted an exclusive effect on ho and a */b * ratio skin color parameters and pH and an appreciable effect on titratable acidity.

Nutritional composition changes in bell pepper as affected by the ripening stage of fruits at harvest or postharvest storage and assessed non-destructively.

BACKGROUND: Nutritional quality in bell pepper is related to the ripening stage of the fruit at harvest and postharvest storage. Its determination requires time-consuming, tissue-destructive, analytical laboratory techniques. The objective of this study was to investigate the effect of ripening stage and of postharvest storage period on fruit nutritional quality, and whether it is feasible to develop reliable models for assessing the nutritional components in peppers using non-destructive methods. The dry matter, soluble solids, ascorbic acid, phenolics, chlorophylls, carotenoids and the total antioxidant capacity were determined in bell pepper fruits at six ripening stages, from green to full red, during storage at 10 °C for 8 days. Color, chlorophyll fluorescence, visible/near infrared (Vis/NIR) spectroscopy, red-green-blue (R-G-B) and red-green-near infrared (R-G-NIR) digital imaging were tested for assessing the nutritional quality of peppers. RESULTS: The nutritional composition was mainly affected by the ripening stage of bell pepper fruits at harvest and only to a small degree by the storage period. Indeed, the more advanced ripening stage of fruit at harvest resulted in superior nutritional quality. Most of the non-destructive techniques reliably predicted the internal quality of the fruit. The genetic algorithm (GA), the variable importance in projection (VIP) scores, and the variable inflation factor (VIF) tests identified nine distinct regions and four specific wavelengths on the whole visible/NIR electromagnetic spectrum that exhibited the most significant effect in the assessment of the nutritional components. CONCLUSION: It is possible to predict individual nutritional components in bell pepper fruit reliably and non-destructively, and irrespective of the ripening stage of fruits at harvest. © 2021 Society of Chemical Industry.

Silencing of ascorbate oxidase results in reduced growth, altered ascorbic acid levels and ripening pattern in melon fruit.

Ascorbate oxidase (AO, EC 1.10.3.3) is a copper-containing enzyme localized at the apoplast, where it catalyzes the oxidation of ascorbic acid (AA) to dehydroascorbic acid (DHA) via monodehydroascorbic acid (MDHA) intermediate. Despite it has been extensively studied, no biological roles have been definitively ascribed. To understand the role of AO in plant metabolism, fruit growth and physiology, we suppressed AO expression in melon (Cucumis melo L.) fruit. Reduction of AO activity increased AA content in melon fruit, which is the result of repression of AA oxidation and simultaneous induction of certain biosynthetic and recycling genes. As a consequence, ascorbate redox state was altered in the apoplast. Interestingly, transgenic melon fruit displayed increased ethylene production rate coincided with elevated levels of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO, EC 1.14.17.4) activity and gene expression, which might contribute to earlier ripening. Moreover, AO suppressed transgenic melon fruit exhibited a dramatic arrest in fruit growth, due to a simultaneous decrease in fruit cell size and in plasmalemma (PM) ATPase activity. All the above, support for the first time, the in vivo AO participation in the rapid fruit growth of Cucurbitaceae and further suggest an alternative route for AA increase in ripening fruit.

Improvement of sea fennel (Crithmum maritimum L.) nutritional value through iodine biofortification in a hydroponic floating system.

Sea fennel is an herbaceous aromatic and edible halophyte, naturally occurring in coastal areas of the Mediterranean basin. Besides its scientific interest as a salt-tolerant species it exhibits considerable nutritional value and economical potential. As sea fennel is distributed in maritime areas, where natural iodine is available in high concentrations, the aim of this study was to evaluate whether sea fennel has the potential to accumulate elevated iodine concentrations under cultivation. A biofortification experiment in a hydroponic system applying two forms of iodine, KI and KIO3 in different concentrations was set up and monitored using sophisticated targeted elementary and metabolite analysis. The biofortification potential and possible effects on nutritional value were investigated. This study revealed that both iodine forms increased the iodine content of sea fennel tissues. Nutritional and health promoting components, biomass production but also antioxidant potential were stable or even improved under the iodine treatments.

Melatonin and resveratrol reverse the toxic effect of high boron (B) and modulate biochemical parameters in pepper plants (Capsicum annuum L.).

The objectives of this research were to test a possible involvement of melatonin (MEL) and resveratrol (RES) in restoring growth and to control boron (B) toxicity in peppers. The plants were subjected to four different nutrient solution treatments as following: 1) half-strength Hoagland's nutrient solution (Control), 2) half-strength Hoagland's nutrient solution+100 µM B (100 µMB), 3) half-strength Hoagland's nutrient solution+100 µM boron+100 µMresveratrol (100 µMRES), and 4) half-strength Hoagland's nutrient solution+100 µM B+1 µMmelatonin (1 µM MEL). Pepper plants subjected to B excess (100 µM) for 68 days (d) exhibited visible B toxicity symptoms, reduced rate of photosynthesis (Pn) and reduced dry weight (DW), while their leaf and fruit had the greatest increase of B concentration. The reduction of photosynthesis was restored, the reduction of DW was prevented, while the B leaf and fruit accumulation was moderated with the application of both 100 µMresveratrol (RES) and 1 µMmelatonin (MEL). Moreover, plants exposed to MEL and/or RES displayed no visible B toxicity symptoms. The present study revealed a novel role of MEL and/or RES in the adaptation of pepper plants to B excess based on plant growth, physiological and biochemical criteria.