Effect of home-refrigerator storage temperature on tomato quality

Postharvest storage, handling and distribution of fruit at low temperatures is the most common and manageable approach to control ripening and subsequent deterioration and to maximize product shelf-life. However, tomatoes, as many other subtropical fruits, are susceptible to develop symptoms of chilling injury, a physiological disorder caused by the exposure to low temperature above the freezing point. Development of chilling injury depends on temperature, time, ripening stage and tomato type/cultivar. We studied the effect of home-refrigerator storage temperature on the quality of two types of tomato: cocktail tomato (cultivars ‘Amoroso’ and ‘Brioso’) and truss tomato (cultivars ‘Capricia’ and ‘Roterno’). Fully ripe tomatoes were stored for 10 days at two temperatures: 4°C as simulation of home-refrigerator storage and 15°C as an optimal storage temperature. We evaluated several quality parameters: weight loss, firmness, soluble solid content, titratable acidity, carbohydrates, titratable acidity and citrate content. Although we did not observe any apparent symptom of chilling injury, we found that 4°C temperature stimulates firmness decay in both cocktail tomato cultivars, increasing fruit susceptibility to mechanical injury. Moreover, already after 5 days of 4°C storage, tomatoes generally showed decreased sugar and increased acid content (especially in cocktail tomatoes) compared to 15°C stored fruit, indicating a loss of sensoric quality at 4°C

Tomato quality: from the field to the consumer : interactions between genotype, cultivation and postharvest conditions

The preservation of product quality in the marketing chain is of great importance for the final financial result of all stakeholders and consumer satisfaction. Improve product quality management requires an understanding of the various aspects of product and requires the availability of techniques to measure quality in an easy and objective way. The aim of the study was to obtain more insight of the effect of both pre-and post-harvest factors on the quality of tomatoes as experienced by the consumer. In this dissertation, the effect of growing conditions (especially in closed greenhouses) on post-harvest quality of different tomato varieties was discussed. It was also examined the effects of storage of fruits at low temperatures. For the measurement of volatile aroma compounds, essential for the taste, a new method was developed based on PTR-MS coupled to an “artificial mouth”. In this manner, the aroma substances profile could be measured as that released into the mouth during eating of the tomatoes. Cold storage leads to a rapid decrease of important flavor substances, and also shows the connection with the depletion of compounds important for the color red mainly lycopene. After warming up, not all flavors back to previous levels and less desirable substances (off-flavors) are also produced. The results provide guidance on how the cold tolerance of the varieties can be improved.</p

Il Pooling-score (P-score): Variabilit\ue0 inter- e intra-individuale nella valutazione endoscopica della gravit\ue0 della disfagia

This study evaluated the intra- and inter-rater reliability of the Pooling score (P-score) in clinical endoscopic evaluation of severity of swal- lowing disorder, considering excess residue in the pharynx and larynx. The score (minimum 4 - maximum 11) is obtained by the sum of the scores given to the site of the bolus, the amount and ability to control residue/bolus pooling, the latter assessed on the basis of cough, raclage, number of dry voluntary or re ex swallowing acts ( 5). Four judges evaluated 30 short lms of pharyngeal transit of 10 solid (1/4 of a cracker), 11 creamy (1 tablespoon of jam) and 9 liquid (1 tablespoon of 5 cc of water coloured with methlyene blue, 1 ml in 100 ml) boluses in 23 subjects (10 M/13 F, age from 31 to 76 yrs, mean age 58.56\ub111.76 years) with different pathologies. The lms were randomly distributed on two CDs, which differed in terms of the sequence of the lms, and were given to judges (after an explanatory ses- sion) at time 0, 24 hours later (time 1) and after 7 days (time 2). The inter- and intra-rater reliability of the P-score was calculated using the intra-class correlation coef cient (ICC; 3,k). The possibility that consistency of boluses could affect the scoring of the lms was considered. The ICC for site, amount, management and the P-score total was found to be, respectively, 0.999, 0.997, 1.00 and 0.999. Clinical evaluation of a criterion of severity of a swallowing disorder remains a crucial point in the management of patients with pathologies that predispose to complications. The P-score, derived from static and dynamic parameters, yielded a very high correlation among the scores attributed by the four judges during observations carried out at different times. Bolus consistencies did not affect the outcome of the test: the analysis of variance, performed to verify if the scores attributed by the four judges to the parameters selected, might be in uenced by the different consistencies of the boluses, was not signi cant. These initial data validate the clinical use of the P-score in the management of patients with deglutition disorders by a multidisciplinary team

Tackling the grapevine Pectate Lyase gene family and its role in the berry texture determination

Grapevine (Vitis vinifera L.) is one of the most commercially valuable fruit trees worldwide. Table grapes represent an important economic sector, where consumers highly appreciate the berry firmness trait. Although several studies have addressed the key role of the cell wall in fruit firmness, the main players among cell wall degrading enzymes during fruit ripening are still unclear. This work characterizes the grapevine Pectate Lyase (VvPL) gene family which catalyses the eliminative cleavage of de-esterified pectin during the berry development. Using the latest grapevine genome assembly and annotation, 17 members of the family containing the PL domain were identified. To identify the VvPL members most involved in pectin degradation during fruit softening, an in-silico analysis in Expression Atlas and in public RNA-Seq repositories was performed. Additionally, gene expression of the VvPL genes was evaluated in table grape varieties showing contrasting texture profiles. Our results demonstrated that specific VvPL genes were up-regulated in the softer variety compared to the firmer one, suggesting their active role in the softening process during berry development. Furthermore, two VvPL genes were selected for functional characterization via genome editing with CRISPR/Cas9 technology in the table grape variety ‘Sugraone

A breach in plant defences: Pseudomonas syringae pv. actinidiae targets ethylene signalling to overcome Actinidia chinensis pathogen responses

8openInternationalBothEthylene interacts with other plant hormones to modulate many aspects of plant metabolism, including defence and stomata regulation. Therefore, its manipulation may allow plant pathogens to overcome the host’s immune responses. This work investigates the role of ethylene as a virulence factor for Pseudomonas syringae pv. actinidiae (Psa), the aetiological agent of the bacterial canker of kiwifruit. The pandemic, highly virulent biovar of this pathogen produces ethylene, whereas the biovars isolated in Japan and Korea do not. Ethylene production is modulated in planta by light/dark cycle. Exogenous ethylene application stimulates bacterial virulence, and restricts or increases host colonisation if performed before or after inoculation, respectively. The deletion of a gene, unrelated to known bacterial biosynthetic pathways and putatively encoding for an oxidoreductase, abolishes ethylene production and reduces the pathogen growth rate in planta. Ethylene production by Psa may be a recently and independently evolved virulence trait in the arms race against the host. Plant- and pathogen-derived ethylene may concur in the activation/suppression of immune responses, in the chemotaxis toward a suitable entry point, or in the endophytic colonisationopenCellini, Antonio; Donati, Irene; Farneti, Brian; Khomenko, Iuliia; Buriani, Giampaolo; Biasioli, Franco; Cristescu, Simona M.; Spinelli, Francesco;Cellini, A.; Donati, I.; Farneti, B.; Khomenko, I.; Buriani, G.; Biasioli, F.; Cristescu, S.M.; Spinelli, F

Transcriptomic and volatilomic profiles reveal Neofabraea vagabunda infection-induced changes in susceptible and resistant apples during storage

Bull’s eye rot is one of the most severe diseases that may affect apple fruit during post-harvest storage. It is caused by the fungus Neofabraea vagabunda, and the mechanism by which the pathogen infects the fruits is only partially understood. In particular, very little is known about the molecular mechanisms regulating the interaction between the pathogen and the host during symptoms development. Despite different apple cultivars show divergent levels of resistance to the pathogen, the genetic basis of these responses is still unknown. In order to better understand the molecular mechanisms occurring in the apple fruit during N. vagabunda infection, a large-scale transcriptome study by RNA-Seq analysis was performed, comparing fruits of the sensitive ‘Roho’ cultivar and the resistant cultivar ‘Ariane’ after artificial infection with N. vagabunda and a storage period of four months. Transcriptomic analyses revealed the regulation of several classes of genes during this period, some of which may be involved in apple-pathogen interaction, such as superoxide dismutases and heat shock proteins (HSPs), ethylene-responsive transcription factors (ERFs), carboxylesterases and NAC transcription factors gene families. Moreover, a volatile analysis was performed, revealing differences in the volatile profile between the resistant and the susceptible cultivar that may help to elucidate the resistance mechanism. RNA-Seq data highlighted several classes of pathogen-related genes, such as genes coding for enzymes involved in cell wall disruption and in reactive oxygen species (ROS) homeostasis, being differentially regulated between resistant and susceptible fruits and between diseased and healthy fruits of the same cultivar, indicating that apples are capable of perceiving and triggering a molecular response to N. vagabunda infection. Some volatiles, as ethanol and methanol, but also furan and formaldehyde, might be potential markers for N. vagabunda infection; others, such as hexenal and methyl acetate, were found to be putatively involved in regulating apple-fungi interactio

A breach in plant defences: Pseudomonas syringae pv. actinidiae targets ethylene signalling to overcome Actinidia chinensis pathogen responses

Ethylene interacts with other plant hormones to modulate many aspects of plant metabolism, including defence and stomata regulation. Therefore, its manipulation may allow plant pathogens to overcome the host’s immune responses. This work investigates the role of ethylene as a virulence factor for Pseudomonas syringae pv. actinidiae (Psa), the aetiological agent of the bacterial canker of kiwifruit. The pandemic, highly virulent biovar of this pathogen produces ethylene, whereas the biovars isolated in Japan and Korea do not. Ethylene production is modulated in planta by light/dark cycle. Exogenous ethylene application stimulates bacterial virulence, and restricts or increases host colonisation if performed before or after inoculation, respectively. The deletion of a gene, unrelated to known bacterial biosynthetic pathways and putatively encoding for an oxidoreductase, abolishes ethylene production and reduces the pathogen growth rate in planta. Ethylene production by Psa may be a recently and independently evolved virulence trait in the arms race against the host. Plantand pathogen-derived ethylene may concur in the activation/suppression of immune responses, in the chemotaxis toward a suitable entry point, or in the endophytic colonisation

Does organic farming increase raspberry quality, aroma and beneficial bacterial biodiversity?

Plant-associated microbes can shape plant phenotype, performance, and productivity. Cultivation methods can influence the plant microbiome structure and differences observed in the nutritional quality of differently grown fruits might be due to variations in the microbiome taxonomic and functional composition. Here, the influence of organic and integrated pest management (IPM) cultivation on quality, aroma and microbiome of raspberry (Rubus idaeus L.) fruits was evaluated. Differences in the fruit microbiome of organic and IPM raspberry were examined by next-generation sequencing and bacterial isolates characterization to highlight the potential contribution of the resident-microflora to fruit characteristics and aroma. The cultivation method strongly influenced fruit nutraceutical traits, aroma and epiphytic bacterial biocoenosis. Organic cultivation resulted in smaller fruits with a higher anthocyanidins content and lower titratable acidity content in comparison to IPM berries. Management practices also influenced the amounts of acids, ketones, aldehydes and monoterpenes, emitted by fruits. Our results suggest that the effects on fruit quality could be related to differences in the population of Gluconobacter, Sphingomonas, Rosenbergiella, Brevibacillus and Methylobacterium on fruit. Finally, changes in fruit aroma can be partly explained by volatile organic compounds (VOCs) emitted by key bacterial genera characterizing organic and IPM raspberry fruit

Exploring blueberry aroma complexity by chromatographic and direct-injection spectrometric techniques

Blueberry (Vaccinium spp.) fruit consumption has increased over the last 5 years, becoming the second most important soft fruit species after strawberry. Despite the possible economic and sensory impact, the blueberry volatile organic compound (VOC) composition has been poorly investigated. Thus, the great impact of the aroma on fruit marketability stimulates the need to step forward in the understanding of this quality trait. Beside the strong effect of ripening, blueberry aroma profile also varies due to the broad genetic differences among Vaccinium species that have been differently introgressed in modern commercial cultivars through breeding activity. In the present study, divided into two different activities, the complexity of blueberry aroma was explored by an exhaustive untargeted VOC analysis, performed by two complementary methods: SPME-GC-MS (solid phase microextraction-gas chromatography-mass spectrometry) and PTR-ToF-MS (proton transfer reaction-time of flight-mass spectrometry). The first experiment was aimed at determining the VOC modifications during blueberry ripening for five commercially representative cultivars ("Biloxi," "Brigitta Blue," "Centurion," "Chandler," and "Ozark Blue") harvested at four ripening stages (green, pink, ripe, and over-ripe) to outline VOCs dynamic during fruit development. The objective of the second experiment was to confirm the analytical capability of PTR-ToF-MS to profile blueberry genotypes and to identify the most characterizing VOCs. In this case, 11 accessions belonging to different Vaccinium species were employed: V. corymbosum L. ("Brigitta," "Chandler," "Liberty," and "Ozark Blue"), V. virgatum Aiton ("Centurion," "Powder Blue," and "Sky Blue"), V. myrtillus L. (three wild genotypes of different mountain locations), and one accession of V. cylindraceum Smith. This comprehensive characterization of blueberry aroma allowed the identification of a wide pull of VOCs, for the most aldehydes, alcohols, terpenoids, and esters that can be used as putative biomarkers to rapidly evaluate the blueberry aroma variations related to ripening and/or senescence as well as to genetic background differences. Moreover, the obtained results demonstrated the complementarity between chromatographic and direct-injection mass spectrometric techniques to study the blueberry aroma