ETHYLENE INSENSITIVE2 (EIN2), an integral membrane protein and a central positive regulator of ethylene responses, plays a key role in the ethylene signaling pathway. It mediates in cross-talk between abscisic acid (ABA) and ethylene pathways. The interplay between these two stress phytohormones is a major determinant cut flower's vase life, but the details of this interplay have not been elucidated. The crosstalk between ABA homeostasis and the ethylene signaling pathway in growth, stomatal aperture regulation, photosynthesis, water loss, and senescence during ethylene-induced senescence were studied in carnation wild type and EIN2-suppressed plantlets. Our findings revealed a significant role for EIN2 in determination of plant size (internode size and apical meristem growth). Ethylene reduced anthocyanin and elevated flavenol content, whereas EIN2 suppression changed the color of petals from white (in wild type plant) to pale yellow. The EIN2 suppression improved flower longevity and reduced senescence in carnation cut flowers under the presence of ethylene by regulation of senescence-related genes. Decrease in flavenol accumulation in EIN2-suppressed plantlets caused ROS accumulation, which is a signal for stomatal closure. Photosynthetic capacity of EIN2-suppressed plantlets was higher than that of wild type plantlets. EIN2-suppressed plantlets showed smaller stomata and lower stomatal densities than the stomata of wild-type plantlets. Senescence-related genes were down-regulated by EIN2 suppression. Expression of genes involved in ABA biosynthesis/catabolism were down/up-regulated by ethylene exposure in wild-type, while remained constant in EIN2-suppressed plantlets. In conclusion, antagonistic effects of ethylene on ABA-related responses were removed in EIN2-suppressed plantlets. These findings elucidate mechanisms underlying limited vase life of flowers harvested with leaves and pave the way of extending vase life of cut flowers.

BACKGROUND:Flower petals serve to attract pollinators and inherently have a short life span. The senescence of these plant parts is programmed in the flower's developmental plan. Also at the cellular level, petal cell death is highly programmed going through a number of different phases that culminate in cellular suicide (programmed cell death - PCD). The signalling, biochemical, molecular and gene determinants involved in the regulation of PCD and the morphological characteristics of the process in flower petals have to some extent been described. Still important issues of theoretical and practical significance related to PCD functioning and its contribution to petal deterioration remain unsolved. SCOPE:This review discusses the occurrence and role of PCD in petal senescence in models of ornamental plants. For comparison, the distinctive and common features of plant and animal PCD types are outlined. The two major plant cell death categories - vacuolar (V) PCD, reminiscent to animal autophagic PCD and apoptosis-like (AL) PCD, sharing features with animal apoptosis - and their ontribution to petal senescence are discussed. CONCLUSIONS:The findings indicate that cellular PCD is tightly connected to petal senescence and support the view that senescence is a specific form of developmental PCD (senescence/PCD), dominated by large scale autophagy and eventual breakdown of the vacuole membrane. Depending on the measured PCD markers, petal cell death is often characterized being either V-PCD or AL-PCD. However, alongside the ongoing V-PCD, in early or late stages of senescence, often AL-PCD-associated features are observed. This indicates that, in senescing petal cells, both PCD pathways operate in parallel and are presumably interconnected. The specific conditions may determine their relative contribution to cell death. The cell death cascade may, in general, start earlier in parenchyma than in epidermal cells. In a fully open, visibly non-senescent flower, a large part of the mesophyll cells may already have died or even disappeared, indicating that petal senescence is well on its way and cannot be reversed. Petal abscission may occur in both non-senescent and senescent petals and its regulation seems independent from petal PCD.

Basil (Ocimum basilicum L.) is susceptible to chilling injury (CI), leading to significant postharvest quality loss. This research aimed to identify key metabolites involved in CI of basil during cold storage to better understand the underlying mechanisms. Metabolite profiles of basil leaves stored at 4 and 12 degrees C for up to 12 days were quantified by 1H NMR and GC-MS. At 4 degrees C shelf life was reduced due to CI. At 4 degrees C, several osmoprotectants, including proline, gamma-aminobutyric acid, trehalose and myo-inositol increased, whereas antioxidants like ascorbic acid and rosmarinic acid decreased; the latter likely due to scavenging reactive oxygen species. During chilling stress, antioxidant defence pathways were upregulated and carbohydrate related energy pathways were downregulated. We suggest that CI in basil associates with redirection of carbohydrate flux towards antioxidant defence systems, leading to energy depletion. This energy depletion is hypothesized as a primary trigger for CI in postharvest basil.

In this study, the effectiveness of preharvest fertigation using calcium thiosulfate (CaTS) and potassium thiosulfate (KTS) to enhance the shelf life of bell peppers was investigated. The nutrient solution was enriched with KTS (either 0.26 or 0.53 mM of a commercial formulation) or CaTS (0.66 mM of a commercial formulation), and compared to a commercial source-based nutrient solution as a control. Fruit quality attributes and the activity of key enzymes involved in oxidative stress defense, enzymatic browning, cell wall degradation, and membrane lipid degradation were investigated for 30 days of storage. Results showed that CaTS and KTS treatments preserved protein (a secondary energy reserve) and proline content, and enhanced the fruit's PSII activity throughout storage. Despite increased phenylalanine ammonia-lyase activity, CaTS and KTS fertigation did not affect polyphenol oxidase activity. CaTS and KTS fertigation increased the activity of five (out of seven) antioxidant enzymes and impaired the activity of one (out of two) cell wall hydrolytic enzyme. CaTS was the most effective treatment, followed by KTS (0.53 mM), in causing these promotive effects. In conclusion, preharvest application of CaTS (0.66 mM) and KTS (0.53 mM) prolonged the postharvest life and delayed senescence of bell pepper fruits by preserving fruit weight, firmness, and photosynthetic performance, as well as enhancing the antioxidant defense system.

Vertical farming is considered to be a key enabler for transforming agrifood systems, especially in or nearby urbanized areas. Vertical farming systems (VFS) are advanced indoor cropping systems that allow for highly intensified and standardized plant production. The close control of environmental parameters makes crop production stable and repeatable, ensuring year-round uniform product quality and quantity irrespective of location. However, due to continuous changes in plant physiology and development, as well as frequent changes in electricity prices, the optimum conditions for crop production and its associated costs can change within days or even minutes. This makes it beneficial to dynamically adjust setpoints for light (intensity, spectrum, pattern, and daylength), CO2, temperature, humidity, air flow, and water and nutrient availability. In this review, we highlight the beneficial effects that dynamic growth conditions can have on key plant processes, including improvements in photosynthetic gas exchange, transpiration, organ growth, development, light interception, flowering, and product quality. Our novel findings based on modeling and experimentation demonstrate that a dynamic daily light intensity pattern that responds to frequent changes in electricity prices can save costs without reducing biomass. Further, we argue that a smart, dynamic VFS climate management requires feedback mechanisms: several mobile and immobile sensors could work in combination to continuously monitor the crop, generating data that feeds into crop growth models, which, in turn, generate climate setpoints. In addition, we posit that breeding for the VFS environment is at a very early stage and highlight traits for breeding for this specialized environment. We envision a continuous feedback loop between dynamic crop management, crop monitoring, and trait selection for genotypes that are specialized for these conditions.

Postharvest performance of fresh horticultural products is largely affected by processing and storage conditions. Various practices such as chemical and physical treatments and controlled or modified atmosphere storage can delay the senescence and reduce deterioration. However, the treatments and storage environment may also be stressful and induce detrimental physiological, metabolic and molecular changes resulting in quality loss. The macroscopic symptoms of quality decline have gotten an appropriate attention, but the processes underlying the defects at the cellular level are not well understood. It is suggested that some of the postharvest disorders may involve programmed cell death (PCD): a genetically determined process of cellular suicide indispensable for normal plant development and an important mechanism for survival in response to stressful environmental factors of biotic and abiotic origin. In this review the contribution of PCD to postharvest senescence and storage-related deterioration of perishable horticultural products is discussed. For better comprehension of plant PCD, the major concepts are outlined. Senescence is considered as a specific form of PCD. Examples of recent and earlier findings demonstrating the incidence of storage-related PCD are presented. It is suggested that revealing the implication of PCD in postharvest disorders may trigger the development of new or optimized preservation strategies addressing cell death. Identification of PCD related markers can be a promising tool for predicting the shelf life of harvested products. The control over postharvest stress-induced PCD may be beneficial for the postharvest industry in sustaining the quality in the supply chain as well as in breeding programs for obtaining products with improved tolerance to storage-induced stress.

This study was conducted with the aim of providing the latest situation on banana genotypic diversity present in the market places, their cultivations, their market chain and trading facilities in Maluku Province, Indonesia. Survey method was used, in which different markets, farmers and government institutions were visited and interviewed. Seventeen genotypes of three different species and different genome and ploidy levels were seen at the market places with two highly demanded genotypes, Pisang Raja Hitam and Pisang 40 Hari. The major suppliers of banana commodities in Ambon market were Ceram, Ambon, Buru, Obi and Bacan Islands. Lack of knowledge in implementing proper cultural practices, lack of capital, lack of aid provided by government and several other obstacles have been the reasons for low banana production in Maluku Province as indicated by this study, and confirmed by the survey's data provided by the government. Lack of sufficient infra-structure for large scale cultivations, storage and transport, and the use of harmful chemicals in post-harvest handling are some of the factors potentially hindering the international trading of banana products. However, there are development plans by the government, which possibly improve the banana export situation in the future.

Extending shelf life, improving quality, and reducing waste of leafy vegetables during transport and storage are key to tackling the global food challenge. Leafy vegetables – as the most popular crop grown in indoor vertical farms – are considered an important contributor to a healthy diet but generally have a short shelf life. In this chapter, we provide a comprehensive definition of quality and review studies on the effect of high photosynthetic photon flux density (PPFD) applied prior to harvest on phytochemicals in leafy vegetables. Increasing levels of phytochemicals (vitamin C, phenolics and carbohydrates) under high PPFD can directly improve health-related values at harvest, and more importantly, through their involvement in metabolic and redox homeostasis, ensure sufficient antioxidant capacity in leaves and suppress quality decay in storage. Increased PPFD during growth can be integrated with indoor vertical farming to improve quality and extend the shelf life of leafy vegetables.

There are significant effects of preharvest factors on postharvest quality. We are only able to maintain the high quality obtained by proper cultivation and growing techniques. Unfortunately, we lose a significant part of produced horticultural crops including ornamental products after harvest. The lost product has a huge carbon footprint. The most important postharvest factor in maintaining quality and preventing losses of ornamentals is temperature. The cut flowers that are not sensitive to chilling injury should be stored close to 0 C. This, however, requires more energy for cooling and thus needs the use and development of sustainable cooling principles. One obvious solution for storage facilities is the use of solar power. Various systems have been developed to store surplus energy during the daytime in the form of an ice buffer that can be used during the night to keep the product cool. Other smart cooling principles such as the Quest technology developed at Wageningen Food and Bio-based Research, runs on reefer containers. These aid in saving energy and lowering the carbon footprint during refrigerated transport. Cut flowers should be transported at low temperatures to keep them fresh from grower to consumer. However, refrigerated trucks use about 25% more fuel than non -refrigerated ones. Shipping containers by sea is a more sustainable alternative to conventional airfreight and overland transport with significantly smaller CO2 emissions per ton per kilometer carried. Eco-friendly treatments such as spray, pulsing, and vase solutions are another important issue in sustainability of flower industry. After harvest, cut flowers are commonly treated with a range of compounds with the aim to improve the storage performance and to prolong the vase life. Eco-friendly and sustainable pulsing and vase solutions such as natural extracts from medicinal plants should be preferred as a biocide in pulsing or vase solutions to maintain the postharvest quality of cut flowers and greens. Plastics are being replaced by biodegradable packaging, ecofriendly renewable and recyclable materials, new heat-sealable, fiber-based materials from sustainably managed or certified forests, and other sustainable coatings. Novel procedures based on temperature treatments under controlled atmospheres (CATT) can replace the use of harmful chemicals in insect disinfection. Finally, advanced control of the distribution chain from grower till consumer can ensure that product losses are minimized, contributing to the sustainability of the value chain.

Basil (Ocimum basilicum L.) is a temperature sensitive plant and suffers from chilling injury (CI), especially during the postharvest storage. We investigated the effect of additional far-red light (FR) during cultivation at two temperatures on postharvest chilling tolerance. Basil was cultivated under red-white Light Emitting Diodes (LED) at 25 degrees C. During the last 3 weeks before harvest, plants were maintained at a high temperature (25 degrees C) or exposed to a low temperature (15 degrees C). Furthermore, plants were exposed to additional FR (180 mu mol m(-2) s(-1)) for different durations (0, 1 or 3 weeks). After harvest, leaves were stored at 4 and 12 degrees C in darkness. Overall visual quality and maximum quantum yield of PS II (Fv/Fm) as indicators of chilling injury were monitored every third day for 15 d. Abscisic acid (ABA) and jasmonic acid (JA), carbohydrates, and antioxidants were measured at harvest and after 9 d of storage at 4 degrees C. Additional FR improved the chilling tolerance at both cultivation temperatures. Cultivation temperature had no effect on postharvest chilling tolerance. Hormone levels in basil leaves at harvest were not affected by FR. This indicates that ABA and JA are not involved in development of FR-induced chilling tolerance in basil. FR had no effect on the levels of antioxidants at harvest whereas the levels of soluble sugars and starch increased under additional FR. The positive effect of adding FR during cultivation on chilling tolerance in basil may be due to the increase in soluble sugars and starch.

To improve yield in lettuce during indoor cultivation, far-red radiation (FR, 700-800 nm) is often added to the photosynthetic active radiation (PAR, 400-700 nm). Different scenarios was applied in this study: in one scenario FR is applied throughout the 16 h photoperiod (FR-Day); in another scenario FR is applied for a short duration (1 h) at the end of the day (FR-EOD). We have shown that FR-Day is optimal for improving yield, whereas FR-EOD is optimal for production efficiency (Zou et al., 2019). Here, we evaluated the impact of both scenarios on the postharvest quality of lettuce. Shelf-life of excised packaged (polyethylene film) leaves was monitored during dark storage at 4 and 16 degrees C, respectively. FR during cultivation decreased the content of major health-promoting metabolites at harvest, especially under FR-Day. At 4 degrees C, shelf-life was not affected by the cultivation regime. At 16 degrees C, instead, FR was associated with increased postharvest deterioration rate and reduced overall visual quality throughout storage. The reduced shelf-life following FR during cultivation was related to elevated O-2(center dot-) content along with decreased activity of enzymatic (superoxide dismutase) and reduced levels of non-enzymatic (ca-rotenoids, total phenolics, and flavonoids) antioxidants. We conclude that FR during cultivation especially under FR-Day is associated with reduced nutraceutical quality at harvest, and potentially shorter shelf-life. Notably, the latter was only observed under inappropriate postharvest temperature management.

A novel approach to developing robust calibration models for predicting dry matter in mango fruit is presented. The robust methodology includes automatic iterative downweighting of outlying samples during the chemometric modelling to learn a robust mathematical relationship between near-infrared (NIR) spectra and dry matter (DM). The robust models were compared with traditional partial least-squares (PLS) modelling by validation on independent data derived from four different cultivars of another origin and measured by a different instrument (without calibration transfer) from an open access mango dataset. The results showed that downweighting of several outliers in the robust modelling approach reduced the root mean squared error of prediction (RMSEP) from 1.03 % DM to 0.75 % DM compared to that achieved with a PLS model tested on samples of different cultivars. Furthermore, independent tests of the robust model on sample sets composed of data from different cultivars, origin, and measured with a different NIR instrument reduced the RMSEP from 2.06 % DM to 0.89 % DM without any need for model update and transfer. The robust models can help improve the prediction of fruit traits and are a further step in broadening the application of NIR spectroscopy in horticultural practice.

Sugar beet leaves can be a viable and economically interesting source of high-quality protein for the food industry. We investigated how storage conditions and leaf wounding at harvest affect the content and quality of the soluble protein. After collection, leaves were either stored intact or shredded to mimic wounding induced by commercial leaf harvesters. Leaf material was stored in small volumes at different temperatures to assess leaf physiology or in larger volumes to assess temperature development at different locations in the bins. Protein degradation was more pronounced at higher storage temperatures. Wounding accelerated the degradation of soluble protein at all temperatures. Both wounding and storage at higher temperatures greatly stimulated respiration activity and heat production. At temperatures below 5°C, ribulose-1,5-biphosphate carboxylase oxygenase (RuBisCO) in intact leaves was preserved for up to 3 weeks. At temperatures of 30-40°C, RuBisCO degradation occurred within 48 h. Degradation was more pronounced in shredded leaves. In 0.8-m3 storage bins at ambient temperature, core temperatures rapidly increased, up to 25°C in intact leaves and up to 45°C in shredded leaves within 2-3 days. Immediate storage at 5°C greatly suppressed the temperature increase in intact but not in shredded leaves. The indirect effect of excessive wounding, that is, heat production, is discussed as the pivotal factor responsible for increased degradation of protein. For optimal retention of soluble protein levels and quality in harvested sugar beet leaves, it is advised to minimize wounding and to store the material at temperatures around -5°C. PRACTICAL APPLICATION: To preserve the soluble protein content and quality for at least 3 weeks, sugar beet leaves should be harvested with minimal wounding and stored at temperatures between 1 and 5°C. When aiming to store minimally wounded leaves in larger volumes, it must be ensured that the product temperature in the core of the biomass meets the temperature criterium or the cooling strategy must be adjusted. The principles of minimal wounding and low temperature storage are transferable to other leafy crops that are harvested for food protein.

Background: Refrigerated containers or 'reefers' are essential for transporting fresh fruit and vegetables in transnational supply chains. By refrigeration, they ensure that food quality is better preserved and food losses are reduced. Countries that produce fresh produce also unlock new markets for export through refrigerated container transport.Scope and approach: The authors have worked in the research and development of reefer-facilitated supply chains for over two decades. Based on our research and engineering work with key stakeholders, we provide our perspective on how the industry will or should evolve. We also elaborate on upcoming trends and key bottlenecks the industry faces. This paper touches upon subjects relevant to the global fruit and vegetable trade. These topics involve (1) the fresh produce reefer market, (2) the climate inside the reefer, including temperature uniformity and controlled atmosphere trends, (3) sustainability aspects such as greenhouse gas emissions and potential energy savings, and (4) the move towards smart reefers and the use of digital food twins.Key findings: We particularly encourage more research on using a controlled atmosphere to save energy and better preserve foods, the effectiveness of ethylene scrubbers in reefers, synergizing the data acquisition pipelines of different sensor systems, and integrating these data with other parts of the supply chain into one data ecosystem.Conclusions: As future trends, we foresee a further reduction of the carbon footprint and developments in digital twins of the refrigerated container and its cargo to monitor and predict future fruit and vegetable quality during transit and beyond.

Background: Certain food bioactives and nutraceuticals need to be preserved from environmental factors such as pH, light, oxygen, temperature, and enzymatic degradation because they are chemically or physically instable. Moreover, these compounds may be degraded in gastrointestinal system and are not absorbed in body. Being a novel technique, encapsulation suggested effective solution to the limitations of delivering intact bioactive ingredients to the target sites. Chitosan has been extensively valued as a delivery system for bioactive ingredients. Scope and approach: In this review article, we discuss the potential applications of chitosan-based carriers as encapsulating agent in food industry. Chitosan alone or modified chitosan particles have been extensively used as a coating on liposome and alginate beads, as well as a delivery system for bioactive ingredients such as essential oils, flavor, vitamins, antioxidants, and probiotics. Key findings and conclusions: Chitosan is a cationic natural polysaccharide which has emerged as a suitable carrier in delivering nutraceuticals as it is non-toxic, biodegradable and biocompatible. Chitosan encapsulation can protect bioactive ingredients from extreme conditions such as pH and temperature. Chitosan capsules have proved to be suitable carriers for essential oils, flavors, vitamins, antioxidants, and probiotics.

Encapsulation and controlled release of bioactive compounds is now an established protocol to enhance the bioavailability and long-lasting efficacy of therapeutic and disease-preventive agents while minimizing or eliminating side effects. Currently, there are a number of products approved by the regulatory authorities for Human or animal use, which contain encapsulated drugs, nutraceuticals, diagnostic agents, cosmetics, or even vaccines. Manufacturing the encapsulation/carrier systems requires special considerations with respect to scalability, environmental issues, and cost-effectiveness. Among the many available procedures for large-scale preparation of micro- and nanocarriers, the "Mozafari method" has proven to be simple to implement and reproducible technique that does not require sophisticated equipment or use of potentially toxic solvents. The mentioned proprietary method and patents in which this method is utilized or incorporated is the focus of the present review article.

Blue light, measuring from 400 to 500 nm, is generally assumed to increase the content of antioxidants in plants independent of the species. Blue light stimulates the biosynthesis of phenolic compounds such as flavonoids and their subclass anthocyanins from the phenylpropanoid pathway. Flavonoids, anthocyanins, and phenolic acids are strong reactive oxygen species (ROS) scavengers and may lessen the symptoms of abiotic stresses such as chilling. We tested the hypothesis that a high percentage of blue light induces the accumulation of antioxidants and that this effect depends on the photosynthetic photon flux density (PPFD, 400–700 nm). The effect may be more pronounced at a lower PPFD. We investigated the changes in primary and secondary metabolites of basil in response to the percentage of blue light (9, 33, 65, and 100%) applied either as a 5-day End-Of-Production (EOP) treatment or continuous throughout the growth cycle in the green cv. Dolly. We also studied if the response to the percentage of blue light (9 or 90%) was dependent on the total PPFD (100 or 300 μmol m–2 s–1 PPFD) when applied as a 5-day EOP treatment in the green cv. Dolly and the purple cv. Rosie. For both green and purple basil, it was found that the percentage of blue light had little effect on the levels of antioxidants (rosmarinic acid, total ascorbic acid, total flavonoids, and total anthocyanins) at harvest and no interactive effect with PPFD was found. Antioxidants generally decreased during postharvest storage, wherein the decrease was more pronounced at 4 than at 12°C. Chilling injury, as judged from a decrease in Fv/Fm values and from the occurrence of black necrotic areas, was not affected by the percentage of blue light. Particularly, chilling tolerance in the purple cultivar was increased in plants grown under higher PPFD. This may be related to the increased levels of soluble sugar and starch in leaves from high PPFD treated plants.

This study aims to test the hypothesis that skin dehydration can cause the development of cork-like layers in the avocado fruit skin which may negatively affect Vis-NIR spectroscopy. To test this, dehydration treatment was applied on avocado fruit by storing them at low relative humidity (RH) during ripening treatment. Furthermore, to demonstrate that the hypothesis was not only valid for a single instrument and in general valid for any type of Vis-NIR instrument the avocados were also measured with two different spectrometers i.e., lab-based, and handheld. Since the two instruments have two different measurement geometries i.e., diffuse reflection and interaction, the study also tests which geometry was best for the measurement of DMC in dehydrated avocados. The results showed that the dehydration of avocado fruit negatively affects the performance of Vis-NIR calibrations compared to the non-dehydrated fruit. The root mean squared error of cross-validation (RMSEcv) on internal test set for dehydrated and non-dehydrated fruit were up to 1.49 % dw/fw and 1.02 % dw/fw, respectively. The hypothesis was true for both lab-based and hand-held instruments, and the root mean squared error of prediction on internal test set were up to 28 % higher for dehydrated fruits. The performance of interaction measurement mode was better (RMSEcv = 0.98 % dw/fw) than the diffuse reflection mode (RMSEcv = 1.21 % dw/fw) for non-dehydrated fruit, however, both modes achieved similar performance (RMSEcv = similar to 1.42 % dw/fw) for dehydrated fruit. The poorer performance of Vis-NIR models on dehydrated avocado fruit can be accepted as a limitation of Vis-NIR spectroscopy for avocado fruit analysis.