Postharvest Quality Research Articles

Effect of Paclobutrazol and GA4+7 on Post-Harvest Storage of Dragon Fruit [Hylocereus costaricensis (Web.) Britton and Rose]

Dragon fruit undergoes rapid senescence during storage. This study identified the synergistic effect of Paclobutrazol and GA4+7 with different concentrations on the postharvest quality and shelf life of dragon fruits stored at ambient conditions. This study was conducted in completely randomized design. Dragon fruits were treated with different concentration of Paclobutrazol and GA4+7 and stored at ambient temperature for 13 days. Changes in fruit’s physiological loss of weight, firmness, total soluble solid, titrable acidity, and ascorbic acid were periodically recorded. The results indicated that the Paclobutrazol treated with 200mg significantly reduced the decrease of physiological loss of weight, firmness, total soluble solids, titrable acidity and ascorbic acid content. The results showed that Paclobutrazol treated with 200mg is the most effective treatment than GA4+7 for improving the postharvest quality and prolong the shelf life of dragon fruits when stored at ambient condition.

Desempenho morfofisiologico e qualidade pós-colheita de cultivares de alface hidropônica em condições de temperatura elevada

ABSTRACT Lettuce (Lactuca sativa) is the most economically important leafy vegetable in Brazil, with the crisp type being the most popular among producers. However, in regions with hot climates, lettuce has production limitations due to bolting, requiring knowledge on the behavior of cultivars available on the market. Thus, the objective of the present study was to characterize the performance of crisp lettuce cultivars in terms of their productive, physiological, and postharvest quality aspects when grown under hydroponic cultivation and high temperature conditions. The assay was performed in a greenhouse and the plants were grown in a hydroponic system of DFT type. The average temperature during the experiment was 30.33 °C. The experimental design used was completely randomized with nine treatments (Veneranda, Cristina, Olinda, Mônica, Cinderela, Grand Rapids, Itapuã Super, Crocantela, and Simpson Black Seed), with four replications. The cultivars were analyzed in terms of their productive, physiological, and postharvest quality performances. The Olinda and Cristina cultivars showed the best performance in growth, physiological, and postharvest variables. However, the cultivars had distinct sensory characteristics. Bolting negatively affected gas exchange, production, and postharvest quality of lettuce cultivars Veneranda, Mônica, Grand Rapids, and Cinderela. In addition, it was observed that the pigment content was not determinant for the expression of bolting. Therefore, this study recommends the use of cultivars Olinda and Cristina for the hydroponic cultivation under high temperature conditions.

Production and quality of watermelon subjected to biofertilizer fertilization

The expansion of the area with organic agriculture is due to the market trend towards the consumption of healthier foods. However, with the increase in the cost of fertilizers imported by the country, the adjustment of doses and management practices with alternative sources for plant nutrition, such as biofertilizer, can be an alternative for the sustainability of properties. The experiment was conducted in the experimental field of Bebedouro (CEB) of EMBRAPA Semi-Arid Region in Petrolina-PE, Brazil, from September to December 2019, to evaluate the effect of biofertilizer doses on the production aspects of three watermelon varieties in the semi-arid region. The experimental design was randomized blocks, in a 6 x 3 factorial scheme, corresponding to six doses of biofertilizer (0; 80; 160; 240; 320 and 400 mL plant-1) and three varieties of watermelon (Explorer, Red Heaven, and Majestic), with four replicates. Yield, number of fruits per plant, average fruit mass, fruit diameter, fruit length, length: diameter ratio, pulp firmness, rind thickness, pH, total soluble solids, titratable acidity and soluble solids/titratable acidity ratio were analyzed. The number of fruits per plant was not altered by biofertilizer doses. However, the variables yield and average fruit mass were altered by the interaction between varieties and biofertilizer doses. With yield of 40.22 t ha-1 obtained at the dose 201.33 mL plant-1, the Explorer variety proved to be more efficient with the use of biofertilizer in organic system. Positive responses to biofertilizer application in postharvest quality attributes were obtained in Explorer and Red Heaven varieties.

Preservation of Postharvest Quality of Fresh-Cut Cauliflower through Exogenous Putrescine, Citric Acid and Salicylic Acid Treatments

Cauliflower is among the perishable vegetables after harvest. In recent years, the popularity of fresh-cut cauliflower has increased among consumers as a minimally processed product. This study was carried out to determine the effects of exogenous putrescine (PUT), citric acid (CA) and salicylic acid (SA) treatments on postharvest quality of fresh-cut cauliflower stored at 4±0.5 °C and 90±5% relative humidity for 21 days. In the study, a total of seven different treatments using two different doses (0.5 and 1.0 mM) of PUT, CA and SA were investigated. To evaluate the quality of fresh-cut cauliflower, the necessary measurements and analyzes were performed at periodic intervals on days 0, 7, 14, and 21 of storage. The results demonstrated that quality properties changed significantly depending on the postharvest treatments and storage durations. With the increase of storage duration, weight loss and ash content increased, while K, Zn and Cu contents decreased. In general, the treatments examined in the study had positive effects on postharvest quality of cauliflower. Among the treatments, especially 1.0 mM PUT was found to be more effective. Compared to the control, 1.0 mM PUT treatment decreased weight loss by 61.32%, though it increased protein content by 14.48% and P content by 21.55%. It was concluded that 1.0 mM PUT treatment can be recommended as an alternative application method to extend the storage life of fresh-cut cauliflower and reduce postharvest quality losses.

Sulfur dioxide generating pads containing different concentrations of sodium metabisulfite maintains postharvest quality of ‘Hicaznar’ pomegranate

This study investigated the effects of different sulfur dioxide (SO2) generating pads containing different concentrations of sodium metabisulfite (Na2S2O5) on the storage of ‘Hicaznar’ pomegranate fruit. For this purpose, the pomegranates were harvested at optimal harvest maturity (total soluble solids (TSS): 17.70 %, titratable acidity (TA): 1.57 % citric acid). The first, second and third groups were treated with SO2 generating pads containing different concentrations of Na2S2O5 (1.5, 3.0 and 4.5 g). The fourth group was control which received no treatment. The SO2 generating pads were placed on top of the fruit with butter paper containing holes were kept between the fruit and pads. All the treatments were packaged under modified atmosphere packages (MAP) and stored at 6 °C and 90–95 % relative humidity (RH). The fruit samples for quality analysis were taken at 45, 90, 120, 150 and 180 days (d) of cold storage (CS). Post removal, the samples from each treatment were kept at 20 °C for additional 3 d to determine shelf life (SL) performance of fruit. Extending storage duration showed increase in weight loss, h° values, total flavonoid content, carbon dioxide (CO2) levels and decay index while decrease in L*, C* values, appearance and taste scores, TSS content, TA, total phenolic content, total antioxidant activity, total anthocyanin, ascorbic acid, organic acids (citric, malic, succinic and oxalic acids) contents, phenolic compounds (gallic, protocatechuic and chlorogenic acid), oxygen (O2) levels and SO2 production in MAP. SO2 generating pads reduced weight loss and decay index. The highest taste value was recorded in 3.0 g SO2 generating pads. The highest h° value was in 1.5 g SO2 generating pads while the greatest total anthocyanin content in CS was in 3.0 and 4.5 g with maximum total anthocyanin content in SL was recorded in 1.5 and 4.5 g SO2 generating pads. SO2 generating pads exhibited maximum total phenolic content, total antioxidant activity and gallic acid content as compared to control. There were no SO2 residues in pomegranate arils throughout the storage. It can be concluded that SO2 generating pads can be a potential tool to preserve the postharvest quality of ‘Hicaznar’ pomegranate for 180 d of CS.

Inhibitory Effect and Potential Antagonistic Mechanism of Isolated Epiphytic Yeasts against Botrytis cinerea and Alternaria alternata in Postharvest Blueberry Fruits

This study evaluated the biocontrol effect of isolated epiphytic yeasts (Papiliotrema terrestris, Hanseniaspora uvarum, and Rhodosporidium glutinis) against Botrytis cinerea and Alternaria alternata in blueberry fruits and its possible mechanisms. Our findings indicated that the three tested yeasts exerted a good biocontrol effect on postharvest diseases in blueberry, and that H. uvarum was the most effective. In addition, the three tested yeasts could improve the postharvest storage quality of blueberry fruits to some extent. H. uvarum demonstrated the strongest direct inhibitory effect on pathogens by suppressing spore germination, mycelial growth, and antifungal volatile organic compound (VOC) production. P. terrestris showed the highest extracellular lytic enzymes activities. It also had better adaptation to low temperature in fruit wounds at 4 °C. The biofilm formation capacity was suggested to be the main action mechanism of R. glutinis, which rapidly colonized fruit wounds at 20 °C. Several action mechanisms are employed by the superb biocontrol yeasts, while yeast strains possess distinctive characteristics and have substantially different action mechanisms.

Thermal insulation box design for maintaining cool temperature and the postharvest quality of okra

Postharvest loss of okra is caused by its high respiration rate and temperature fluctuations in the supply chain. To address this, five thermal insulation boxes were designed, combining different materials, and evaluated for okra quality during simulated transportation and storage. The treatments included the standard foam box, metalized foam sheet (two layers consisting of aluminum foil and expanded polyethylene), prototype-A (three layers consisting of dual layer of aluminum foil and expanded polyethylene), prototype-B (four layers consisting of aluminum foil, nonwoven, expanded polyethylene, and aluminum foil), and standard regular slotted container. Material tests revealed that aluminum foil and expanded polyethylene had the lowest thermal heat energy. The composite sandwich box design, prototype-A, demonstrated the highest maximum insulation time of 28 h and thermal resistance of 0.332 m2°C/W. Prototype-A and prototype-B effectively maintained low temperature fluctuation, minimized air and okra temperature changes, and maintained 6.19 to 8.25 % CO2, which was within an acceptable range of 4–10 % for okra. Both prototypes exhibited reduced percentage mass loss in okra below 5 %. Importantly, both prototypes demonstrated the lowest incidence of okra pod surface browning and maintained the quality for 6 d, surpassing metalized foam sheet and standard regular slotted container. These findings offer sandwich design with 3 or 4 layers as promising alternatives for thermal insulation boxes in cold chain management, enhancing the transport packaging of okra under ambient environments compared to the standard foam box.

Post-harvest quality of lettuce treated with ozonised water in a microbubble system

ABSTRACT This study aimed to determine the post-harvest quality of lettuce treated with ozonised water obtained in a microbubble system. The inlet ozone concentration was fixed at 3.5 mg L−1, which allowed obtaining 1.60 mg L−1 of ozone in the water. Six treatments were adopted: (i) control (untreated lettuce); (ii) ozonised water/5 min; (iii) ozonised water/10 min; (iv) oxygen/5 min; (v) oxygen/10 min; and (vi) chlorine/15 min. After the treatments, the samples were stored at 5°C and at a relative humidity of 80%. Microbiological and physicochemical analyses were performed immediately after ozonation (day 0) and after 3 and 6 days of storage. Reductions in the count of aerobic mesophiles and molds and yeasts were observed, immediately after the treatments with ozonised water. For the treatments ozonised water/5 min and ozonised water/10 min, the reductions of aerobic mesophiles were equal to 0.71 and 1.59 log reduction respectively, when compared to the control. Despite the significant increase in the leakage of electrolytes, especially when it was adopted exposure time to ozonated water of 10 min, it was considered that the conditions adopted favour the lettuce sanitation, without causing changes that make the product non-tradable.

Advances in the Understanding of Postharvest Physiological Changes and the Storage and Preservation of Pitaya

Highly prized for its unique taste and appearance, pitaya is a tasty, low-calorie fruit. It has a high-water content, a high metabolism, and a high susceptibility to pathogens, resulting in an irreversible process of tissue degeneration or quality degradation and eventual loss of commercial value, leading to economic loss. High quality fruits are a key guarantee for the healthy development of economic advantages. However, the understanding of postharvest conservation technology and the regulation of maturation, and senescence of pitaya are lacking. To better understand the means of postharvest storage of pitaya, extend the shelf life of pitaya fruit and prospect the postharvest storage technology, this paper analyzes and compares the postharvest quality changes of pitaya fruit, preservation technology, and senescence regulation mechanisms. This study provides research directions for the development of postharvest storage and preservation technology.

Blue light treatment delays postharvest ripening of kiwifruit by suppressing ethylene biosynthesis, starch degradation, and cell wall metabolism

The study aimed to investigate the effects of blue light (BL) on the postharvest ripening and softening of kiwifruit. The postharvest ripening of kiwifruit were significantly inhibited by BL; 100 μmol m−2 s−1 light intensity exhibited the best effect. The delay of postharvest ripening of kiwifruit by BL was associated with the inhibition of total soluble solids accumulation, reduction in respiratory rate and ethylene production as well as 1-aminocyclopropane-1-carboxylate synthase and 1-aminocyclopropane-1-carboxylic acid oxidase activities. Moreover, it also inhibited starch degradation and related enzyme activities (α-amylase and β-amylase), prevented the degradation of protopectin, cellulose and hemicellulose while promoting the accumulation of water soluble pectin. Additionally, it suppressed the activities of polygalacturonase, pectinlyase, pectin methylesterase, and cellulase. Transcriptome and gene expression analyses showed that BL-treated kiwifruit had lower expression levels of genes involved in ethylene biosynthesis, starch degradation, and cell wall metabolism, compared with the dark controls. BL also altered transcription factor responses to light, such as v-myb avian myeloblastosis viral oncogene homolog (MYB) and basic helix-loop-helix (bHLH) families. In summary, this study analyzed the physiological and molecular mechanisms by which BL delays the postharvest ripening of kiwifruit and provides a new preservation method for the postharvest quality maintenance of kiwifruit.

Comparative physiological and transcriptomic analysis reveals an improved biological control efficacy of Sporidiobolus pararoseus Y16 enhanced with ascorbic acid against the oxidative stress tolerance caused by Penicillium expansum in pears

Sporidiobolus pararoseus Y16, a species of significant ecological importance, has distinctive physiological and biological regulatory systems that aid in its survival and environmental adaptation. The goal of this investigation was to understand the complex interactions between physiological and molecular mechanisms in pear fruits as induced by S. pararoseus Y16. The study investigated the use of S. pararoseus Y16 and ascorbic acid (VC) in combination in controlling blue mold decay in pears via physiological and transcriptomic approach. The study results showed that treatment of S. pararoseus Y16 with 150 μg/mL VC reduced pears blue mold disease incidence from 43% to 11%. Furthermore, the combination of S. pararoseus Y16 and VC significantly inhibited mycelia growth and spore germination of Penicillium expansum in the pear's wounds. The pre-treatment did not impair post-harvest qualities of pear fruit but increased antioxidant enzyme activity specifically polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT) activities as well as phenylalanine ammonia-lyase (PAL) enzyme activity. The transcriptome analysis further uncovered 395 differentially expressed genes (DEGs) and pathways involved in defense mechanisms and disease resistance. Notable pathways of the DEGs include plant-pathogen interaction, tyrosine metabolism, and hormone signal transduction pathways. The integrative approach with both physiological and transcriptomic tools to investigate postharvest pathology in pear fruits with clarification on how S. pararoseus Y16 enhanced with VC, improved gene expression for disease defense, and create alternative controls strategies for managing postharvest diseases.

Enhancing Postharvest Quality and Shelf Life of Strawberries through Advanced Coating Technologies: A Comprehensive Investigation of Chitosan and Glycine Betaine Nanoparticle Treatments.

The application of natural polymer-based coatings presents a viable approach to prolong the longevity of fruits and tissue damage. This study investigates the impact of treatments involving glycine betaine (GB), chitosan (CTS), and chitosan-coated glycine betaine nanoparticles (CTS-GB NPs) on preserving the quality and reducing decay in strawberry fruits. The fruits were subjected to treatments with GB (1 mM), CTS (0.1%), CTS-GB NPs (0.1%), or distilled water at 20 °C for 5 min, followed by storage at 4 °C for 12 days. The results indicate that CTS and CTS-GB NPs treatments resulted in the highest tissue firmness, total anthocyanin content, and ascorbate peroxidase activity, while exhibiting the lowest decay percentage and weight loss, as well as reduced malondialdehyde levels at the end of storage. GB, CTS, and CTS-GB NPs treatments demonstrated elevated catalase activity and antioxidant capacity, coupled with lower electrolyte leakage and hydrogen peroxide levels. These treatments did not significantly differ from each other but were markedly different from the control. The results substantiate that CTS and CTS-GB NPs treatments effectively preserve strawberry quality and extend storage life by bolstering antioxidant capacity and mitigating free radical damage.

Physiological Processes Affecting Postharvest Quality of Fresh Fruits and Vegetables

Fresh fruits and vegetables are integral components of a balanced diet, providing essential nutrients and contributing to human health. However, the postharvest quality of these perishable commodities is greatly influenced by various physiological processes that occur after harvest. This article reviews the key physiological processes affecting postharvest quality, including respiration, transpiration, ripening, senescence, and enzymatic activity. Understanding these processes is crucial for optimizing postharvest handling practices to extend shelf life, maintain quality attributes such as texture, flavor, color, and nutritional content, and minimize losses. Strategies to manage these physiological processes, including temperature and humidity control, modified atmosphere packaging, and the use of postharvest treatments, are discussed. Additionally, emerging technologies and innovative approaches for enhancing postharvest quality and extending the storage life of fresh fruits and vegetables are highlighted. By elucidating the complex interplay of physiological factors influencing postharvest quality, this review aims to provide valuable insights for researchers, practitioners, and stakeholders involved in the fresh produce supply chain, ultimately contributing to the promotion of food security and sustainability.

Impact of abscisic acid treatment on postharvest storage quality and volatile flavor substances in blueberries

AbstractTo investigate the impact of abscisic acid (ABA) on the postharvest flavor and quality of blueberries, this study employed different concentrations of ABA (400 μM ABA, 600 μM ABA, and 800 μM ABA) to treat the blueberries. The treated blueberries were then stored at 4°C (~80% relative humidity) for 35 day. Subsequently, genes associated with the metabolism of volatile aromatic substances and fatty acids in postharvest blueberries were assessed using real‐time PCR. Our results revealed that the treatment of ABA could maintain a high level of nutrient and aromatic substances in blueberries. Particularly, 600 μM ABA caused most significant changes in fatty acid metabolism‐related enzyme activities, such as lipoxygenase, hydroperoxide lyase, alcohol dehydrogenase, as well as related gene expressions, like VcLOX2S, VcHPL, VcADH1‐1, VcADH1‐2, VcADH1‐3, and VcADH1‐4. In addition, Furthermore, the blueberries treated with 600 μM ABA exhibited a superior quality when compared to the control group. This superior quality included higher levels of total acid, ascorbic acid, total phenol, anthocyanin, soluble sugar contents, and so forth. In conclusion, postharvest ABA treatment decelerated the decrease in volatile aroma substances and effectively maintained the flavor of blueberries.

Effect of Pre-Harvest Calcium Treatment on Post-Harvest Fruit Quality of Nanfeng Tangerine

To investigate the effect of calcium (Ca) application on post-harvest fruit quality in Nanfeng tangerines, this study sprayed three calcium fertilizers (Calbit, Larry 8 Calcium, and Suspended Calcium) before harvesting. The fruit quality was assessed over a storage period of 0–60 d at a controlled room temperature of 20 ± 5 °C. The evaluation methods included principal component analysis (PCA) and linearly weighted summation. Pre-harvest calcium treatments increased the fruit calcium content and maintained higher firmness and shear. Compared to the control group, fruits treated with Calbit exhibited decreased levels of decay, weight loss, and respiration rates. Additionally, they demonstrated higher values of L*, b*, C*, and H° and lower values of a* and CCI. Moreover, the Larry 8 Calcium and Calbit treatments increased the levels of soluble solids, total soluble sugars, titratable acids, and VC content in the fruit. They accelerated the decomposition of tartaric, oxalic, and citric acids in the pulp, promoting the accumulation of sucrose and glucose. PCA and comprehensive evaluation scores indicated that the comprehensive scores assessing the storage quality of Nanfeng tangerine fruits treated with pre-harvest Larry 8 Calcium and Calbit were higher than those of the control group. The highest composite quality scores for Calbit-treated fruits were observed at 40 and 60 d, and the highest scores for Larry 8 Calcium were recorded at other intervals. These findings suggest that pre-harvest calcium application improved the post-harvest fruit quality of Nanfeng tangerines, with Larry 8 Calcium and Calbit emerging as favorable options.

Preharvest Mandarin Rind Disorder: Insights into Varietal Differences and Preharvest Treatments Effects on Postharvest Quality.

The citrus industry loses a significant amount of mandarin fruits either before or shortly after harvesting due to rind disorder. Different citrus cultivars are impacted by a physiological rind disorder that lowers fruit quality and marketability. Although the primary etiology of this condition is unknown, changes in relative humidity (RH) and rind water status can make it worse. The damage is initiated in the fall, especially following rain. It begins with irregular water-soaked areas that develop into dark-brown, necrotic lesions covering large portions of the fruit's surface. The damage is evident in some citrus types such as Satsuma Owari mandarins and other cultivars. In this study, we attempted to understand and control the occurrence of this kind of rind disorder in Satsuma Owari mandarins growing under California conditions. Our data showed that fruit located in the outer part of the canopy suffer more than fruit in the interior canopy. We were able to reduce this damage in Satsuma Owari mandarins by applying 2,4-dichlorophenoxyacetic acid (2,4-D) at 16 milligrams/Liter (mg/L), gibberellic acid (GA3) at 20 mg/L, or Vapor Gard® at 0.5 percent (v/v) at the color break stage. However, GA3 caused a delay in color development by approximately four weeks. GA3-treated fruit changed their color completely four weeks after the control, and the rind damage was at a very low percentage. Delaying rind senescence could be a good strategy to reduce the damage in mandarin orchards. Data showed that in addition to the benefits of the different treatments on preventing rind disorder at harvest, they have some beneficial effects during storage for four weeks either at 0.5 or 7.5 °C.

Near-freezing temperature suppresses avocado (Persea americana Mill.) fruit softening and chilling injury by maintaining cell wall and reactive oxygen species metabolism during storage

To enhance the postharvest quality of avocado (Persea americana Mill.) fruit, this study investigates alterations in cell wall metabolism and reactive oxygen species (ROS) metabolism during near-freezing temperature (NFT) storage, and explores their impact on fruit softening. The fruit was stored at 25 °C, 5 °C, 2 °C, and NFT, respectively. NFT storage retarded firmness loss and chilling injury in comparison with 25 °C, 5 °C, and 2 °C. NFT storage delayed the decrease of ionic-soluble pectin (ISP) and cellulose (CLL) contents by suppressing cell wall degradation enzyme activities. Correlation analysis showed that cell wall degradation enzyme activities were positively correlated to rates of ethylene release and respiration. Moreover, NFT storage maintained higher levels of DPPH and ABTS scavenging abilities, activities of superoxide dismutase, peroxidase, and catalase, as well as ascorbate-glutathione cycle (ascorbic acid, glutathione, glutathione disulfide, ascorbate peroxidase, cycle-related enzymes), thereby inhibited the increase of ROS content, malondialdehyde content, and cell membrane permeability. Fruit firmness and chilling injury were correlated with the contents of hydrogen (H2O2), superoxide anion (O2.-), ISP, and CLL. These results suggested that NFT could suppress fruit softening and chilling injury by inhibiting cell wall degradation through delaying respiration and ethylene production and suppressing ROS production via activation of antioxidant systems, thereby maintaining quality and prolonged storage life during avocado fruit storage.

Genetic architecture of post-harvest tuber quality traits in bush yam (Dioscorea praehensilis Benth.) germplasm through association mapping

IntroductionBush yam (Dioscorea praehensilis Benth.) is an important semi-domesticated food crop in West Africa. Limited information on the genetic architecture and its poor post-harvest tuber quality traits significantly hinder its use as food and source of income. Hence, dissecting the genetics underlying the expression of its post-harvest tuber quality traits is essential for establishing proper breeding schemes.MethodsIn this study, 138 D. praehensilis accessions collected in Ghana were sequenced using Diversity Array Technology (DArTSeq). The materials were profiled for dry matter content (DMC), tuber flesh oxidation (TBOXI) and for tuber flesh hardness (TBhard) during two cropping seasons.Results and discussionDiversity assessment using population structure, principal component analysis and hierarchical clustering methods revealed the presence of three major groups. Six genetic models were used for the trait association analysis using multiple random locus mixed linear model (MrMLM). Sixteen SNP markers distributed across the yam genome were identified to be associated with the evaluated traits. The associated SNP markers displayed a phenotypic variance ranged from 4.22% in TBHard to 16.92% in TBOXI. A total 25 putative candidate genes were identified around the SNP markers. The putative genes were identified to play key roles in tuber bulking, oxidative browning and starch hydroxylase. This study provides a valuable insight on the genetics underlying tuber quality traits in bush yam and opens avenues for developing genomic resources to improve D. praehensilis.

Exogenous CaCl2 delays flesh softening by inhibiting the degradation of cell wall in fresh-cut cantaloupe

Flesh softening is closely related to the quality of postharvest produces. Although the use of calcium chloride (CaCl2) has been shown to inhibit fruit softening, the underlying molecular mechanisms have remained unclear. In our present investigation, CaCl2 treatment resulted in an enhancement of cytosolic free Ca2+ and polysaccharide contents, firmness, and the integrity of the cell wall structure, particularly evident in the denser middle lamella of fresh-cut cantaloupe. CaCl2 treatment also inhibited the cell wall degrading enzyme activities and gene expressions. Moreover, CmCAMTA2 could identify and bind to the CG-box structure of CmCellulase, Cmα-Gal3, and Cmβ-Glu12, thereby suppressing their transcription. In conclusion, current findings illustrated that CaCl2 treatment triggered CmCAMTA2-mediated transcriptional suppression on cell wall degrading genes, inhibited the polysaccharide component degradation, and maintained better structure integrity of the cell wall, thereby delaying the flesh softening of fresh-cut cantaloupe.

Pre-harvest treatments: A different insight into preservation of strawberries

Strawberry is one of the most favored consumed fresh fruits worldwide. However, the major constraint limiting future sustainable production and sales of strawberries is post-harvest decay. Thus, taking a deep look into the effective preservation measures including pre- and post-harvest techniques to retain freshness and inhibit the pathological spoilage of strawberries in the supply chain is of great significance and necessity. At present, relying solely on post-harvest technology is not enough to fix the aim of strawberry fruit preservation and longer shelf life. On the contrary, pre-harvest treatments could be extend shelf life of strawberry fruit and adapt to the diverse post-harvest environments. This review give the latest pre-harvest treatments, their effects on post-harvest quality and storability of strawberries, and develop the expectation of strawberries pre-harvest methods applicated in the future.