Postharvest Physiological Disorders Research Articles

Preharvest salicylic acid and chitosan treatments reduce red drupelet reversion and enhance antioxidant capacity in blackberry fruit

Red drupelet reversion (RDR) is a postharvest physiological disorder affecting fresh blackberries during commercialization. The drupelets revert from fully black to red, causing detriments of the commercial value. The specific mechanism is still being investigated, some reports suggest that the occurrence of RDR is associated with pigment degradation in the fruit, and can be caused or aggravated by mechanical damage and storage conditions. Even, though studies report no significant alteration in blackberry organoleptic properties caused by RDR, the visual aspect of it affects the consumer perception of the fruit quality reducing marketability and ultimately generating economic losses. In this regard, preharvest treatments have been recently reported to have positive effects in reducing RDR in blackberries. In this study, we investigated the effects of chitosan (COS) and salicylic acid (SA) as preharvest treatments on the phenolic compound content and antioxidant capacity of blackberry fruit. The results showed that SA 3 mM and COS 0.25% treatments increased the total phenolic and flavonoid content while also enhancing the antioxidant capacity of blackberries. We also observed that the content of specialized metabolites and the activity of antioxidant enzymes have a negative correlation with the occurrence of RDR in blackberries.

The efficiency of Ca and K nitrate on the control of SERB damage in 'Thomson’ orange by modification of peel physical and chemical characteristics

One of the most severe peel physiological disorders of orange fruits is Stem End Rind Breakdown (SERB), a severe postharvest physiological disorder. We expected foliar Ca and K application to reduce orange SERB by modifying several peel biochemical and physical characteristics. Therefore, one experiment (2018–2020) was designed in complete randomized blocks in four treatments with three replicates. Experimental treatments included foliar spray of (1) K nitrate; (2) Ca nitrate; (3) Ca, and K nitrate separately, with a time interval (Ca + K; combination of treatments 1 and 2); (4) control. The effects of treatments were evaluated on several parameters underlying fruit peel quality at harvest and intensity of SERB damage after 12 wk of fruit storage at 5 ◦C and 85% RH. The results showed that K-treated fruits had higher TSS and TSS/TA than other fruits. Also, the Ca treatments (including Ca and Ca + K treatments) increased Ca content in fruit peels and significantly decreased SERB damage and weight loss by 70% and 30%, respectively. In addition, Thomson orange peel obtained from Ca-treated trees (including Ca and Ca + K treatments) displayed elevated levels of pectin than other fruits. In contrast, the peels of fruits picked from trees sprayed with Ca, especially those treated with Ca + K, exhibited lower levels of total phenolic, antioxidant, and electrolyte leakage than other fruits. This study suggests that foliar application of Ca(NO3)2 and KNO3 during the fruit growth cycle while improving the internal quality of the fruit is an effective agronomical strategy that prolongs Thomson orange shelf life.

Detection of Hardening in Mangosteens Using near-Infrared Hyperspectral Imaging

Mangosteens can develop a postharvest physiological disorder, called “hardening”, which affects their marketability and is not detectable using visual inspection. The hardening disorder of mangosteens was determined by firmness value using the texture analyzer. Near-infrared hyperspectral imaging (NIR-HSI) in the region of 935–1720 nm was tested as a possible rapid and non-destructive method to detect this disorder. The spectra from a region of interest of mangosteens were acquired and used for analysis. Calibration models for firmness of a similarly sized group and a mixed-size group were established using partial least squares regression (PLSR) and support vector machine regression (SVMR). Chemometric algorithms were investigated in order to determine the optimal conditions for establishing the models for firmness. The optimum model was obtained when the fruit were graded into similarly sized groups. Using partial least squares regression (PLSR), the correlation coefficient of prediction (Rp) was 0.87 and the root mean square error of prediction (RMSEP) was 6.25 N. The predictive images for firmness of the fruit were created by interpreting predicted firmness visualized as colors in every pixel. From the data, it was concluded that NIR-HSI can potentially be used to visualize hardening of individual mangosteens based on their predictive images.

A Comprehensive Review on Post Harvest Physiological Disorders in Citrus Fruit Crops (Citrus spp.)

Post-harvest physiological disorders in citrus fruit crops (Citrus spp.) present significant challenges that impact both the economic and environmental aspects of global agriculture. This comprehensive review explored various dimensions of the subject, ranging from the description and classification of major disorders, such as chilling injury, rind staining, water loss, and mold, to the innovative detection and diagnostic techniques being employed in the industry. Through an extensive examination of prevention and management strategies, the review sheds light on pre-harvest factors, post-harvest treatments, and the role of modern technologies and agronomic practices in mitigating these disorders. It also delves into the economic losses and environmental consequences linked to different management approaches, underlining the need for sustainability and eco-friendly solutions. A particular focus is given to the emerging trends and technologies in the field, including nanotechnology, artificial intelligence, and natural treatments, all of which signal a shift towards a more integrated and sustainable management approach. By identifying current research gaps and the necessary future research direction, the review highlights opportunities for innovation and collaboration among growers, researchers, and policymakers. In addition, it emphasizes the broader implications of these disorders and their management on global trade, labor markets, and regulatory landscapes. This review serves as a valuable reference for stakeholders in the citrus industry, providing insights and guidance on best practices, technological advancements, and future perspectives. It represents an essential step towards aligning the citrus production with global sustainability goals and fostering a resilient industry capable of adapting to the ever-changing demands and challenges of the modern world.

Phyto-squalane: A new active ingredient to prevent superficial scald on pears

Superficial scald (SS) is a detrimental postharvest physiological disorder on apples and pears during mid and long-term cold storage. Since diphenylamine (DPA) and ethoxyquin were banned from European markets, there has been an active search for new chemical alternatives. Different phyto-squalane (PSQ-E) treatments (0.1–4.0% w/v) applied at harvest were evaluated in pears from different growing areas and harvest maturity during four consecutive seasons. Fruit quality (external appearance, firmness, soluble solids, ethylene production), SS development, and biomarkers for SS (α-farnesene, CTols) were evaluated at different times during cold storage (up to 210 d, −0.5 to 0.5 °C, > 90%RH). In general, PSQ-E emulsions (0.1–4.0% w/v) applied at harvest were able to significantly reduce or completely prevent SS development in pears from different growing areas, seasons, and maturity levels at harvest. Treated fruit had reduced levels of conjugated trienes (TC281, TC269), but not α-farnesene content. PSQ-E treatments reduced fruit softening, de-greening, and ethylene production compared to the untreated control (UTC) or DPA. Phyto-squalane is a novel new active ingredient that could replace current crop protectants, such as diphenylamine and ethoxyquin, to control superficial scald on pears.

A transcriptomic study of ‘Granny Smith’ apple fruit response to x-ray irradiation using RNA-Seq

Apple (Malus domestica) is a highly valuable fruit that is produced in significant amounts by ten countries and is exported worldwide. Phytosanitary treatment of apples is necessary to limit the spread of destructive pests. Ionizing irradiation is a highly effective non-thermal phytosanitary treatment that is gaining popularity worldwide, as it is an environmentally friendly and chemical-free technique of pest and pathogen control. Irradiation does, however, impact the physiology of the fruit and elicit radiation-induced oxidative stress. This work investigated the transcriptome responses of ‘Granny Smith’ apples subjected to 310 Gy x-ray irradiation after seven days at room temperature (RT) and after 90 days of cold storage, followed by seven days at RT. Extensive transcriptome changes were observed in response to treatment and storage. Early fruit responses included upregulation of pathways involved in cell and DNA repair mechanisms. Drastic shifts in hormone signaling pathways were also observed, as evidenced by the downregulation of auxin and ethylene pathways and the upregulation of salicylic acid and abscisic acid pathways in response to x-ray treatment. Genes encoding various reactive oxygen species scavenging and detoxifying enzymes were upregulated in response to the radiation-induced oxidative stress. The differentially expressed genes identified in this work represent the first comprehensive analysis of apple fruit responses to the commercially used dose of x-ray irradiation. These results will be useful in optimizing future irradiation treatments to minimize post-harvest physiological disorders in apples and preserve quality.

Changes in α-Farnesene and Phenolic Metabolism and the Expression of Associated Genes during the Development of Superficial Scald in Two Distinct Pear Cultivars.

Superficial scald is a postharvest physiological disorder that occurs in pear during and after cold storage. In this study, the superficial scald index; α-farnesene and its oxidation products, conjugated trienols (CTols); phenolic content; and the expression of its related genes were investigated in two different pear cultivars, ‘Wujiuxiang’ (Pyrus communis L.) and ‘Yali’ (Pyrus bretschneideri R.), following 115 days of cold storage at 0 °C followed by 7 days of shelf life at 20 °C. The results indicated that the superficial scald occurred after 115 days of cold storage and became more severe during the shelf life of the ‘Wujiuxiang’ pear, whereas no scald was observed in ‘Yali’. The α-farnesene levels increased rapidly at first and then decreased, while the CTols contents increased significantly in ‘Wujiuxiang’ as compared to ‘Yali’, and the expression levels of the genes involved in α-farnesene and CTols metabolism (HMGR1, HMGR2, GSTU7, GPX5, and GPX6), as well as the phenolic synthesis (PAL1, PAL2, C4H1, 4CL2, C3H, and ANR) of the peel, were significantly up-regulated at the onset of the superficial scald. In addition, the relative conductivity and contents of catechin and epicatechin were higher, and the expression level of the laccase gene (LAC7) significantly increased with the development of superficial scald, while lower contents of chlorogenic acid, arbutin, and isorhamnetin-3-3-glucoside, as well as the lower expression levels of a phenolic-synthesis-related gene (C4H3) and polyphenol oxidase genes (PPO1 and PPO5), were noticed in ‘Wujiuxiang’ as compared to ‘Yali’. The results indicated that the onset and progression of superficial scald were associated with the accumulation of CTols, cell membrane breakdown, and higher catechin, epicatechin, and rutin contents, as well as the expression of associated genes of the peels of pear fruit.

Fruit Traits at Harvest and After Storage Related to the Incidence of Postharvest Physiological Disorders in 'Keitt' Mangoes

Fruit Traits at Harvest and After Storage Related to the Incidence of Postharvest Physiological Disorders in 'Keitt' Mangoes

Role of AOX in low-temperature conditioning induced chilling tolerance in sweetpotato roots

Chilling injury is a significant postharvest physiological disorder in sweetpotatoes during storage. This study investigated the role of alternative oxidase (AOX) in low-temperature conditioning (LTC) induced chilling tolerance in sweetpotato storage roots. Roots were pre-treated with a LTC treatment (12°C for 5 days) or with salicylhydroxamic acid (SHAM, AOX inhibitor) combined with LTC, followed by storage at 4°C for 35 days. Results showed that LTC pre-treatment significantly lowered root chilling injury symptoms, suppressed malondialdehyde levels and the accumulation of reactive oxygen species. However, SHAM reduced the impact triggered by LTC and resulted in lower antioxidant enzyme activities and free proline content, reduced glutathione and adenosine triphosphate contents compared with LTC alone. The results from gene expression analysis showed that LTC-induced higher transcript level of IbAOX1a and IbAOX1b during storage at 4°C. However, SHAM suppressed the effect of LTC. SHAM treatment not only reduced AOX activity but also resulted in a lower AOX transcript and protein abundance, which might contribute to the lower AOX activity observed in the SHAM treated roots. These results suggest that AOX participates in LTC-induced chilling tolerance of sweetpotato storage roots.

Postharvest senescent dark spot development mechanism of Musa acuminata ("Khai" banana) peel associated with chlorophyll degradation and stomata cell death.

The occurrence of the postharvest physiological disorder of dark spots on the peel of the ripened "Khai" banana has led to a reduction in its commercial value. The objective of the present study was to investigate the development mechanisms of senescence dark spots of the "Khai" (Musa AA group) banana peel in relation to chlorophyll degradation and stomata cell death. Freshly harvested bananas (commercial mature green stage) were let to ripened at 25±2°C (90%-95% RH). Peel color, senescent spots, DNA degradation, chlorophyll content, chlorophyll-degrading enzyme activities were assessed. The senescent dark spots developed on the ripened bananas right after 6days of storage, which coincided with remarkably increased DNA degradation, and a rapid decreased of hue angle value and total chlorophyll content which indicated the chlorophyll degradation. The activities of chlorophyllase, chlorophyll-degrading peroxidase and pheophytinase increased gradually to the highest point where the chlorophyll content drastically reduced and the appearance of the dark spots was first recorded after 6days of storage. These dark spots were observed to be surrounded with a bright luminescent ring of hypermodified fluorescent chlorophyll catabolites (FCCs), the product of chlorophyll breakdown. Additionally, the scanning electron microscope (SEM) revealed that the dark spots were found to have originated from the collapsed cells around the stomata of the ripened banana peel whereby the chlorophyll was entirely diminished. PRACTICAL APPLICATIONS: This research revealed the senescent dark spot development mechanisms of the "Khai" banana peel. The dark spot development symptom on the banana peel surface was caused by the senescence and cell death of the relevant stomata, further associated with chlorophyll degradation. Therefore, any further research into minimizing the dark spot symptom must focus on preventing or delaying stomata senescence and cell death.

Effect of postharvest ‘wilting’ treatment and moringa leaf extract incorporated with carboxymethylcellulose to reduce the incidence of postharvest rind physiological disorders of ‘Marsh’ grapefruit (Citrus × paradisi)

Effect of postharvest ‘wilting’ treatment and moringa leaf extract incorporated with carboxymethylcellulose to reduce the incidence of postharvest rind physiological disorders of ‘Marsh’ grapefruit (<i>Citrus</i> × <i>paradisi</i>)

Cell wall and metabolite composition of sweet cherry fruits from two cultivars with contrasting susceptibility to surface pitting during storage

Surface pitting is a serious postharvest physiological disorder in sweet cherries that is observed as skin depressions developed days after bruising. This work aims to compare two cultivars displaying different pitting susceptibilities (‘Kordia’: relatively resistant; ‘Sweetheart’: relatively susceptible) using metabolomics profiling and cell wall sugar characterization at different developmental stages and during postharvest storage. Kordia was significantly firmer than Sweetheart, with 1.4-fold more alcohol-insoluble residues (AIRs). A significant correlation was observed between AIRs and deformation, indicating that the highest yields of cell wall material are positively correlated with the resistance to rupture. Additionally, free d-galacturonic acid was higher in pitted Sweetheart samples, likely indicating greater pectin degradation in this susceptible cultivar. Higher contents of the p-coumaric acid derivatives L-5-oxoproline and d-galactose in Sweetheart cherries were found. The metabolic changes during storage and cell wall composition could influence the susceptibility to surface pitting.

Finger drop: A major concern for storability, post harvest quality and marketing of banana

Physico-chemical changes that occur during ripening affect the post harvest quality and shelf life of banana fruits. Finger drop is a major post harvest physiological disorder that deteriorates the quality of banana particularly in cultivars having genome “A”. Enzyme activity was found responsible for this disorder. Various practices including application of chemicals and growth regulators have been adopted to check this disorder and to improve quality of banana during storage. Research works pertaining to the cause, symptoms and prescribed solutions have been reviewed in this paper.

Pre-harvest climate and post-harvest acclimation to cold prevent from superficial scald development in Granny Smith apples

Superficial scald is one of the most serious postharvest physiological disorders that can affect apples after a prolonged cold storage period. This study investigated the impact of pre- and post-harvest climatic variations on superficial scald in a susceptible apple cultivar. Fruit batches with contrasting phenotypes for superficial scald incidence were identified among several years of “Granny Smith” fruit production. The “low scald” year pre-harvest climate was characterised by a warm period followed by a sudden decrease in temperature, playing the part of an in vivo acclimation to cold storage. This was associated with many abiotic stress responsive genes which were induced in fruit peel. In particular 48 Heat Shock Proteins (HSPs) and 5 Heat Shock transcription Factors (HSFs) were strongly induced at harvest when scald incidence was low. For “high scald” year, a post-harvest acclimation of 1 week was efficient in reducing scald incidence. Expression profiles of stress related genes were affected by the acclimation treatment and indicate fruit physiological adaptations to cold storage. The identified stress-responsive genes, and in particular HSPs, could be useful indicators of the fruit physiological status to predict the risk of scald occurrence as early as harvest.

Preharvest bagging and postharvest calcium treatment affects superficial scald incidence and calcium nutrition during storage of ‘Chili’ pear (Pyrus bretschneideri) fruit

Abstract Superficial scald, which appears as black or brown necrotic patches on the skin, is a serious postharvest physiological disorder of pear fruit. The occurrence of scald in ‘Chili’ pear (Pyrus bretschneideri) fruit during storage at 2 °C in response to preharvest polyethylene (PE) bagging and non-woven fabric bagging has been investigated. The non-woven fabric bagging treatment of fruit prevented scald development, while the PE bagged fruit had a higher incidence of scald than the untreated fruit. Fruit from the PE bagging treatment had lower Ca content, less distribution and lower flux rate of Ca2+ than no bagging and non-woven fabric bagging fruit. The treatment also was associated with greater expression of genes encoding calmodulin-like (CML) proteins, such as PbCML19, PbCML5, PbCML38, PbCML42-1, and PbCML42-2. In contrast, non-woven fabric bagging did not affect the expression of these genes in the fruit. In addition, CaCl2 treatment reduced scald development in PE bagged pear fruit during storage. Our results suggest that Ca2+ may play a role in regulating the occurrence of superficial scald in pear fruit.

The role of ethylene and 1-MCP in early-season sweet cherry ‘Burlat’ storage life

Sweet cherries (Prunus avium L.) are highly appreciated because of their bioactive compound content and attractive organoleptic characteristics; however, they are very perishable. The aim of this work was to investigate whether ethylene and its antagonist 1-MCP affect the postharvest quality of an early-season sweet cherry cultivar, allowing storage life extension. ‘Burlat’ sweet cherries were subjected to three treatments at 1 °C for one month: i) control (air); ii) continuous ethylene supplementation (10 μL L−1); and iii) 1-Methylcyclopropene (1-MCP; 1 μL L−1 for 24 h) followed by air. The incidence of postharvest physiological disorders, the evolution of physical and functional quality traits, and fruit senescence were evaluated at 0, 7, 14, 21, and 30 days. Results showed that sweet cherries were sensitive to both ethylene and 1-MCP treatments. Continuous ethylene exposure reduced abscisic acid accumulation, resulting in higher weight and firmness loss. Moreover, ethylene application decreased titratable acidity through storage, indicating an effect on sweet cherry senescence. No significant differences among treatments were found for soluble solids content and individual sugars. Conversely, 1-MCP preserved firmness during the first 7 days of storage, while reduced the incidence of physiological disorders at the end of storage life. Furthermore, 1-MCP delayed the accumulation of cyanidin-3-O-glucoside for 7 days compared to control and ethylene treated cherries. Taken together these results highlight the potential use of 1-MCP to extend the postharevst life of early season sweet cherry fruit

Nitrogen application rate and harvest date affect red drupelet reversion and postharvest quality in ‘Ouachita’ blackberries

Red drupelet reversion (RDR) is a postharvest physiological disorder in blackberries that causes fruit that is black at harvest to subsequently turn red. This trial aimed to investigate the effects of nitrogen (N) fertiliser application rate on the expression of RDR and postharvest fruit quality.Nitrogen was applied weekly during the growing period via fertigation at a low, medium, and high rates (53, 106, and 212 kg N ha−1 respectively) to ‘Ouachita’ blackberries in 2016 and 2017. Yield, RDR, and postharvest quality were assessed. Harvest date, N application rate, and fruit mass were significant factors in the postharvest expression of RDR. In both years, fruit from the high N treatment exhibited significantly increased incidence and severity of RDR relative to the other two N application rates. Fruit temperatures during harvest of more than 23 °C were associated with higher incidence and severity of RDR in 2017, and smaller fruit were more likely to have no RDR in both years. The high N treatment produced more fruit than the low N treatment in 2016, and more and heavier fruit than both other treatments in 2017.

Genome-wide identification of Dof transcription factors possibly associated with internal browning of postharvest pineapple fruits

DNA binding with one finger (Dof) proteins, which are a family of plant-specific transcription factors (TFs), play vital roles in diverse biotic and abiotic stress responses in plants. Dof TFs from the genome-wide analysis have performed in some species, but information on Dof TFs in pineapple (Ananas comosus L.) fruits during internal browning (IB), which is a postharvest physiological disorder, is lacking. In the present study, we identified 25 putative Dof TFs, that is, designated as AcDof1–AcDof25, which can be classified into seven out of the nine subgroups of the previously characterized Dof proteins, on the basis of the pineapple genome database. Their protein conserved domains displayed similarities to Dof TFs from other plant species. Gene expression profiles indicated that most AcDof genes were upregulated during IB. The further subcellular localizations of four Dof proteins (i.e., AcDof1, AcDof11, AcDof19, and AcDof23) were performed by the transient expression assays. To the best of our knowledge, this work is the first to characterize Dof TF family members and report on their possible role in pineapple fruit IB. Our findings should provide valuable information and novel insights into the Dof TF functions.

Postharvest Physiological Disorders and Organoleptic Properties in Relation to Fungal Disease Incidence in Citrus

Postharvest Physiological Disorders and Organoleptic Properties in Relation to Fungal Disease Incidence in Citrus

Two QTL characterized for soft scald and soggy breakdown in apple (Malus \xd7 domestica) through pedigree-based analysis of a large population of interconnected families

Soft scald and soggy breakdown are important postharvest physiological disorders of apple (Malus × domestica). ‘Honeycrisp’ and some of its offspring are particularly susceptible to developing these disorders. The purpose of this study was to identify molecular markers associated with high incidences of soft scald and soggy breakdown for use in marker-assisted breeding. Towards this aim, we employed a pedigree-based approach using mostly germplasm related to ‘Honeycrisp.’ Two quantitative trait loci (QTL) were consistently identified on linkage groups (LGs) 2 and 16 across the 2014 and 2015 harvest years. The same QTL were identified for both storage disorders, indicating that they may be physiologically related. ‘Honeycrisp’ is homozygous for an identical by state haplotype at the LG2 QTL that was consistently associated with a deleterious effect on soft scald and soggy breakdown incidence. This haplotype was traced through SNP-confirmed pedigrees to the following cultivars: ‘Grimes Golden,’ ‘Northern Spy,’ ‘Rome Beauty,’ and ‘Fireside’ and is common in derived apple germplasm. Haplotypes at the LG16 QTL could not be adequately characterized due to variation between years combined with effects of this QTL being of relatively smaller size and being most evident in individuals that carry two copies of the deleterious haplotype at the LG2 QTL. These results suggest that limiting homozygosity of the deleterious haplotype at the LG2 QTL through marker-assisted breeding would be a valid strategy to limit soft scald and soggy breakdown incidences in apple seedling populations.