Postharvest application of hydrogen peroxide and salicylic acid differently affects the quality and vase life of cut rose (Rosa hybrida L.) petals and leaves

Rose represents an important product in the market of cut flowers. Its quality is related to visual appearance and is affected by oxidative stress and senescence. To maintain the quality and extend the product vase life, innovative technical solutions to be applied in postharvest are needed. In this work the effectiveness of hydrogen peroxide (H2O2) and salicylic acid (SA), was assessed on cut rose leaves and petals. Several physiological indicators of quality were studied, including chlorophyll content, chlorophyll a fluorescence, color, lipid peroxidation, phenolic compounds and anthocyanins. After 7 days of vase life 73.33% of untreated roses were not marketable anymore, while the percentage was lower in response to treatments (47.06% in SA and 25.53% in H2O2). The application of H2O2 induced a reduction in leaf chlorophyll and in the performance index which, at the end of the vase life decrease by 76% and 49% respectively. Consistently, the lipid peroxidation in leaves treated with H2O2 increased by a 53%. After 4 days of vase life, SA allowed maintaining higher levels of anthocyanins in petals compared to H2O2 and to controls. The results obtained allowed individuating different responses, depending on the treatment applied as well as on the plant organ

The Impact of COVID-19 on Horticulture: Critical Issues and Opportunities Derived from an Unexpected Occurrence

The COVID-19 pandemic is causing many victims worldwide and has generated a serious economic crisis. Substantial changes have occurred in the food and ornamental production chains. The aim of the present review has been to summarize some of the main effects that the pandemic is having on horticulture and on the new habits of people. Infections and quarantine measures have prevented the regular flow of certain goods and of connected services. Cases of shortages and/or surpluses, a lack of the availability of labor, and a reduction in demand for some food products and flowers have occurred. New food production approaches have emerged and a reconnection between farmers and consumers has been spreading, thereby facilitating product distribution. Moreover, during the forced isolation, people have had to face periods of stress. The benefits that can be derived from leisure activities related to flowers and ornamental plants, and from access to nature and urban green spaces are increasingly being recognized as relevant. The seriousness of the pandemic will inevitably lead to lasting changes. Therefore, the vulnerability of the pre-COVID-19 distribution chains should be considered and a new food production chain should be drawn up, to increase the resilience of such systems

Benzothiadiazole enhances ascorbate recycling and polyphenols accumulation in blueberry in a cultivar-dependent manner

Benzothiadiazole (BTH) is a functional analogue of salicylic acid able to induce systemic acquired resistance in many horticultural crops. The aim of the work was to investigate how BTH may affect i) fruit quality, ii) ascorbic acid (AsA) oxidation and recycling metabolism and iii) phenolic compounds accumulation, during development and ripening of berries from the two selected cultivars. Blueberry (Vaccinium corymbosum L.) plants (cv ‘Brigitta’ and ‘Duke’) were treated with 0.118 mM BTH every two weeks during ripening, then all fruits of each plant were harvested and divided in four developmental stages. Results indicated that BTH had no marked effects on fruit quality parameters. During the first developmental stage, BTH negatively affected dry matter in both cv, while soluble solids and AsA content were affected in ‘Duke’. In fully ripe berries, BTH reduced dry matter in ‘Duke’ and enhanced soluble solids content in ‘Brigitta’, while diminishing titratable acidity. AsA content was positively affected by BTH in ‘Duke’, but not in ‘Brigitta’. The effect of BTH on the enzymes involved in AsA recycling was recorded in berries at the third (fruit more than half pigmented) and fourth developmental stages. After treatment, in both cv ascorbate peroxidase (APX) activity increased in fully ripe berries, while monodehydroascorbate reductase (MDHAR) activity was stimulated at the third ripening stage. Conversely, the activities of dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were enhanced only in ‘Brigitta’ and in ‘Duke’, respectively. BTH stimulated total polyphenols, flavonoid and anthocyanin accumulation in ‘Brigitta’ and in ‘Duke’ at the third and fourth ripening stages. In fully ripe berries, BTH enhanced the accumulation of delphinidins, cyanidins, petunidins and peonidins in ‘Brigitta’, while in ‘Duke’ it increased all classes of anthocyanidins, including malvidin. On the contrary, the relative proportion of the individual anthocyanins was only slightly affected by BTH treatment, mainly regarding delphinidin and malvidin at the third and fourth stage of ripening of ‘Duke’ and ‘Brigitta’, respectively. These results show that preharvest BTH application can positively impact on fruit bioactive compounds levels, affecting AsA recycling and content and increasing polyphenols accumulation in fruit, but partly depending on cv and ripening stage

Análisis de imagen digital para el estudio del efecto de tratamientos agronómicos en la apariencia de acelga baby (Beta vulgaris L. cicla)

La acelga baby (Swiss chard Beta vulgaris L. cicla) es una verdura comestible con propiedades biofuncionales por su alto contenido en flavonoides, ácidos fenólicos y betalaínas. Mediante estrategias agronómicas es posible modular la biosíntesis de estos compuestos. En este trabajo se ha utilizado el equipo de análisis de imagen DigiEye para la caracterización colorimétrica y morfológica de las variedades Jupiter F1, Rhubarb Chard Sirio y Toro Rosso. La evaluación multiparamétrica ha permitido diferenciar las variedades Jupiter F1 y Rhubarb Chard, las cuales presentan visualmente una gran similitud. Además, se ha estudiado para cada una de las tres variedades los efectos que tienen en su apariencia la aplicación de tratamientos agronómicos como estrés hídrico, aplicación de ácido salicílico y la combinación de ambos respecto a un cultivo control. Los resultados confirman que el análisis de imagen es una poderosa herramienta para la caracterización de este tipo de verdura y sugieren la continuación del estudio a través de análisis químicos

A complex interaction between pre-harvest and post-harvest factors determines fresh-cut melon quality and aroma

Melons are prized for their characteristic aroma, however, pre-harvest growth, stage of ripening at harvest, post-harvest processing and storage conditions lead to quality changes in fresh-cut fruit. We considered changes in metabolites and gene expression over 14 days storage to assess underlying mechanisms and identify potential quality markers. Overall, 99 volatile organic compounds (VOCs) were detected and VOC profiles discriminated between two melon seasons, cut-size, storage temperatures and storage time, although season affected their discriminatory power. Abundance of two VOCs fell rapidly and was not associated with cut size, indicating their use as markers for early changes post-processing. Non-acetate to acetate ester ratio differed between the seasons and correlated with changes in alcohol acyl-transferase (CmAAT1) gene expression. Furthermore, CmAAT1 expression clustered with two ester VOCs that may be potential new products of this enzyme. Season also strongly affected post-harvest sugar content, most likely attributable to meteorological differences during growth. Storage temperature and cut size affected expression of transcription factors ERF71, ERF106, and TINY, whose expression generally rose during storage, probably related to increased stress. Thus, although time × temperature of storage are key factors, pre-harvest conditions and fruit processing impact significantly gene expression and aroma loss post-harvest

Short-Term Post-Harvest Stress that Affects Profiles of Volatile Organic Compounds and Gene Expression in Rocket Salad During Early Post-Harvest Senescence

Once harvested, leaves undergo a process of senescence which shares some features with developmental senescence. These include changes in gene expression, metabolites, and loss of photosynthetic capacity. Of particular interest in fresh produce are changes in nutrient content and the aroma, which is dependent on the profile of volatile organic compounds (VOCs). Leafy salads are subjected to multiple stresses during and shortly after harvest, including mechanical damage, storage or transport under different temperature regimes, and low light. These are thought to impact on later shelf life performance by altering the progress of post-harvest senescence. Short term stresses in the first 24 h after harvest were simulated in wild rocket (Diplotaxis tenuifolia). These included dark (ambient temperature), dark and wounding (ambient temperature), and storage at 4 °C in darkness. The effects of stresses were monitored immediately afterwards and after one week of storage at 10 °C. Expression changes in two NAC transcription factors (orthologues of ANAC059 and ANAC019), and a gene involved in isothiocyanate production (thiocyanate methyltransferase, TMT) were evident immediately after stress treatments with some expression changes persisting following storage. Vitamin C loss and microbial growth on leaves were also affected by stress treatments. VOC profiles were differentially affected by stress treatments and the storage period. Overall, short term post-harvest stresses affected multiple aspects of rocket leaf senescence during chilled storage even after a week. However, different stress combinations elicited different responses

Designing the Future: An Intelligent System for Zero-Mile Food Production by Upcycling Wastewater

The project deals with the environmental problem of water consumption. The aim of this work is to experiment the recycling of dishwasher wastewater through its reuse in growing edible vegetables or ornamental plants; this can also accomplish the valorization of nutrients present in the wastewater. This new process allows to ensure washing functions coupled with vegetables production and to affect users’ environmental awareness and habits, following a user-centered system design approach to understand the users and involve them actively in the system development. The presented work is also aimed to experiment a multidisciplinary approach in order to face environmental problems

Ascorbic Acid Content in ‘Passe-Crassane’ Winter Pear as Affected by 1-Methylcyclopropene during Cold Storage and Shelf Life

'Passe-Crassane' is a winter pear which requires a cold storage period to produce ethylene and properly ripen. In this study, the effects of 1-methylcyclopropene (1-MCP), an ethylene perception inhibitor, were studied during cold storage (30, 60, 90, and 135 days) and shelf life at 20 °C (30 days) of 'Passe-Crassane' pears. Ethylene accumulation was monitored and quality parameters were measured. Oxidative stress of fruit was estimated by measuring lipid peroxidation. The cell antioxidant status was assayed determining ascorbic acid (AsA) content and the activities of the enzymes ascorbate peroxidase (APX), monodehyroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) involved in its oxidation and recycling. AsA content was positively affected by higher temperature (20 °C) and by 1-MCP after 90 days of storage. This effect was more evident after shelf life. Thiobarbituric acid reactive substances (TBARS) increased in pears kept at 20 °C and in treated pears, starting from 60 days of cold storage and remained elevated after shelf life. Although during storage 1-MCP enhanced the activities of APX and DHAR only at 90 days, after shelf life the effect on APX, MDHAR, and DHAR activities was more pronounced and enzyme activities were higher in treated pears sampled after 60 and 90 days of storage. The results indicate that 1-MCP has a beneficial effect on the antioxidant potential of winter pears: it maintained high AsA levels throughout storage and shelf life and improved the enzymatic mechanisms of AsA recycling, especially after shelf life. The effect of 1-MCP on pear ripening may not be solely due to its action on ethylene but also to an increase in antioxidant defense. A stress response linked to lipid peroxidation is triggered by the interaction of cold temperatures and treatment as 'Passe-Crassane' pears acquires ripening competence. However, it may be compensated by the high AsA content