Postharvest Storage Period Research Articles

Prolonged Post-Harvest Preservation in Lettuce (Lactuca sativa L.) by Reducing Water Loss Rate and Chlorophyll Degradation Regulated through Lighting Direction-Induced Morphophysiological Improvements.

To investigate the relationship between the lighting direction-induced morphophysiological traits and post-harvest storage of lettuce, the effects of different lighting directions (top, T; top + side, TS; top + bottom, TB; side + bottom, SB; and top + side + bottom, TSB; the light from different directions for a sum of light intensity of 600 μmol·m-2·s-1 photosynthetic photon flux density (PPFD)) on the growth morphology, root development, leaf thickness, stomatal density, chlorophyll concentration, photosynthesis, and chlorophyll fluorescence, as well as the content of nutrition such as carbohydrates and soluble proteins in lettuce were analyzed. Subsequently, the changes in water loss rate, membrane permeability (measured as relative conductivity and malondialdehyde (MDA) content), brittleness (assessed by both brittleness index and β-galactosidase (β-GAL) activity), and yellowing degree (evaluated based on chlorophyll content, and activities of chlorophyllase (CLH) and pheophytinase (PPH)) were investigated during the storage after harvest. The findings indicate that the TS treatment can effectively reduce shoot height, increase crown width, enhance leaves' length, width, number, and thickness, and improve chlorophyll fluorescence characteristics, photosynthetic capacity, and nutrient content in lettuce before harvest. Specifically, lettuce's leaf thickness and stomatal density showed a significant increase. Reasonable regulation of water loss in post-harvested lettuce is essential for delaying chlorophyll degradation. It was utilized to mitigate the increase in conductivity and hinder the accumulation of MDA in lettuce. The softening speed of leafy vegetables was delayed by effectively regulating the activity of the β-GAL. Chlorophyll degradation was alleviated by affecting CLH and PPH activities. This provides a theoretical basis for investigating the relationship between creating a favorable light environment and enhancing the post-harvest preservation of leafy vegetables, thus prolonging their post-harvest storage period through optimization of their morphophysiological phenotypes.

Effect of postharvest cold storage and subsequent shelf-life on fruit quality and endogenous phytohormones in nectarine fruit

Cold storage is the main approach to extend the postharvest storage period of nectarines. The objective of this study was to investigate fruit quality (flavor and nutrition) and endogenous phytohormone changes and their related transcriptional changes in nectarine fruit after cold storage and subsequent shelf-life, which was performed metabolome, transcriptome and physiological analysis. Cold storage led to irreversible flavor loss due to the inhibition of aroma biosynthesis genes at low temperature. Sugar and organic acid content was affected, with an increase in glucose, fructose and malic acid, and a decrease in sorbitol and citric acid after cold storage or shelf-life. For fruit nutritional quality, total flavonoids or total carotenoids was not significantly affected by cold storage, whereas shelf-life process enhanced their accumulation. The activities of key enzymes for flavonoid biosynthesis, PAL and C4H, were enhanced during the shelf-life process, resulting in a significant increase in flavonoids and enhanced free radicals scavenging capacity. Meanwhile, shelf-life process increased carotenoids content by improving the expression of carotenoid biosynthesis genes PSY, ZDS and ZISO. Additionally, cold storage significantly increased the IAA content and ethylene production, thereby inducing the up-regulation of related signaling transduction genes. The shelf-life process further increased ethylene production, as well as salicylic acid and jasmonic acid content. This study unravels these crucial physiological and associated transcriptional changes of nectarines after cold storage, and may provide a theoretical foundation for improving fruit quality of peaches after cold storage.

Carbon Dots-Mediated Photodynamic Treatment Reduces Postharvest Senescence and Decay of Grapes by Regulating the Antioxidant System.

Grapes are susceptible to mold and decay during postharvest storage, and developing new technologies to extend their storage period has important application value. Photodynamic technology (PDT) in concurrence with carbon dots (CDs) proposes an innovative and eco-friendly preservation strategy. We examined the effects of carbon dots combined with photodynamic treatment on postharvest senescence and antioxidant system of table grape. The compounding of photodynamic technology with a 0.06 g L-1 CDs solution could possibly extend the postharvest storage period of grape berries. Through this strategy, we achieved a decreased rate of fruit rotting and weight loss alongside the delayed deterioration of fruit firmness, soluble solids, and titratable acid. As paired with photodynamic technology, CDs considerably decreased the postharvest storage loss of phenols, flavonoids, and reducing sugars as compared to the control group. Concurrently, it remarkably postponed the build-up of hydrogen peroxide (H2O2), superoxide anion (O2∙-), and malondialdehyde (MDA); elevated the levels of reduced ascorbic acid (AsA) and reduced glutathione (GSH); lowered the levels of dehydroascorbic acid (DHA) and oxidized glutathione (GSSG); raised the ratios of AsA/DHA and GSSH/GSSG; encouraged the activities of superoxide dismutase (SOD) and phenylalanine ammonia-lyase (PAL); and inhibited the activities of polyphenol oxidase (PPO) and lipoxygenase (LOX). Furthermore, it enhanced the iron reduction antioxidant capacity (FRAP) and DPPH radical scavenging capacity of grape berries. CDs combined with photodynamic treatment could efficiently lessen postharvest senescence and decay of grape berry while extending the storage time.

1-Methylcyclopropene and Bacillus Treatment Affects Blueberry Storage Quality and Antioxidant Levels

Blueberries are rich in a variety of functional substances and have high nutritional and health values, but they are not resistant to decline during fresh storage. Here, the effects of six Bacillus species on the storage quality of, and antioxidant levels in, the southern highbush blueberry ‘O’Neal’ fruit were investigated. Bacillus treatments reduced the fruit decay rate, slowed fruit quality decline, inhibited malondialdehyde accumulation, and increased superoxide dismutase and peroxidase activity levels. Bacillus altitudinis Y-14 had the best effect overall. Furthermore, the effects of 1-methylcyclopropene (1-MCP), B. altitudinis Y-14, and 1-MCP + B. altitudinis Y-14 treatments on the storage quality and antioxidant of rabbiteye blueberry ‘Brightwell’ fruit were investigated, and each treatment effectively reduced the decay rate and weight loss of fruit. When stored for 25 days, the decay rate of the 1-MCP + B. altitudinis Y-14 group was only 8.33%, significantly lower than that of the control. The three treatments delayed the decline in fruit quality, inhibited malondialdehyde accumulation, and increased superoxide dismutase and peroxidase activity levels. The 1-MCP + B. altitudinis Y-14 treatment was more conducive to prolonging the postharvest storage period of blueberries and had the best effect in delaying the decline in fruit quality. Thus, combined 1-MCP and B. altitudinis Y-14 treatment may be an effective way to improve the storage quality and extend the storage period of blueberries, which provides a new way for storing and transporting blueberries to reduce costs and improve economic benefits.

History of apple breeding and breeding achievements at FSBSO ARHCBAN

New apple varieties should possess a set of adaptive traits that provide yield, stable fruiting, and highly marketable fruits with a long period of postharvest storage, thus ensuring the profitability of their use in industrial plantings. According to the State Register, the central region of the Russian Federation is one of the leading regions in terms of the number of apple varieties approved for use. Long-term research of scientists and specialists from FSBSO ARHCBAN has greatly contributed to the development and improvement of the assortment both in the region and beyond. The key directions for apple breeding at the institution include improving winter hardiness, resistance to scab, and the columnar shape of the crown. The review article presents the history of shaping the directions for breeding work and modern achievements of FSBSO ARHCBAN in apple breeding, as well as an analysis of the long-term focused scientific activity of breeders. The most significant breeding results were achieved by Prof. V. Kichina, who, together with his students and followers, was the first in Russia to create several columnar apple varieties that offer high winter hardiness, resistance to scab, and marketable qualities of fruits (‘Dialog’, ‘Lukomor’, ‘Malyukha’, ‘Ostankino’, ‘President’, and ‘Chervonets’), as well as fundamentally new high-yielding varieties with a conventional crown shape that possess high adaptability and resistance to pathogens (‘Arkadik’, ‘Legendа’, ‘Marat Busurin’, and ‘Mayak Zagorye’). The article presents the main characteristics of breeding achievements of the last decades: tree crown shape; ripening time of fruits and their qualitative and quantitative indicators (tasting evaluation, average weight, shape, etc.); yield; resistance to abiotic and biotic factors. Data are presented on the use of apple varieties bred by FSBSO ARHCBAN both in agricultural production (on the basis of license agreements) and in scientific and technological cooperation with Russian National Research Universities (inclusion in breeding programs). The apple breeding activities conducted at FSBSO ARHCBAN are described, and the main directions for breeding work are outlined.

Morphological, molecular, and biological characterization of bulb rot pathogens in stored Lanzhou lily and the in vitro antifungal efficacy of three plant essential oils.

Lanzhou lily (Lilium davidii var. willmottiae) is an exclusive sweet lily variety indigenous to China, which is susceptible to bulbous rot caused by fungal infection during storage. This experiment tests the pathogenicity of the pure culture isolated from the diseased tissue was confirmed in accordance with Koch's postulates, and the pathomycetes were identified based on their morphological and molecular characteristics. Furthermore, the biological characteristics of the pathogens were investigated, followed by an evaluation of the antifungal effects of three plant essential oils against them. The results showed that two strains of fungi were isolated from Lanzhou lily rot, which were identified as Fusarium oxysporum Schl. and Aspergillus sydowii (Bain. Et sart.). In addition, the pathogenicity of these two strains of fungi was demonstrated that only F. oxysporum induced rot with similar symptoms during the post-harvest storage period. The biological characteristics of F. oxysporum indicated the potato maltose agar and lily dextrose agar were identified as the most suitable media. Sucrose was determined to be the optimal carbon source, while ammonium nitrate was found to be the best nitrogen source for the growth of F. oxysporum. Mycelial growth and sporulation of F. oxysporum occurred at an optimum pH value of 6. Total darkness facilitated mycelial growth and conidial germination. The ideal temperature for growth was found to be 28°C, while relative humidity did not significantly impact mycelial growth; however, a relative humidity of 55% was most favorable for spore production. Among the three essential oils tested, cinnamon essential oil displayed superior antifungal efficacy against F. oxysporum, whereas angelica essential oil and tea tree essential oil also exhibited moderate inhibitory effects against this pathogen. This research provides valuable theoretical insights for disease control during the storage and transportation of Lanzhou lily.

Transcriptomics and metabolomics reveal the underlying mechanism of drought treatment on anthocyanin accumulation in postharvest blood orange fruit

BackgroundAnthocyanins are the most important compounds for nutritional quality and economic values of blood orange. However, there are few reports on the pre-harvest treatment accelerating the accumulation of anthocyanins in postharvest blood orange fruit. Here, we performed a comparative transcriptome and metabolomics analysis to elucidate the underlying mechanism involved in seasonal drought (SD) treatment during the fruit expansion stage on anthocyanin accumulation in postharvest ‘Tarocco’ blood orange fruit.ResultsOur results showed that SD treatment slowed down the fruit enlargement and increased the sugar accumulation during the fruit development and maturation period. Obviously, under SD treatment, the accumulation of anthocyanin in blood orange fruit during postharvest storage was significantly accelerated and markedly higher than that in CK. Meanwhile, the total flavonoids and phenols content and antioxidant activity in SD treatment fruits were also sensibly increased during postharvest storage. Based on metabolome analysis, we found that substrates required for anthocyanin biosynthesis, such as amino acids and their derivatives, and phenolic acids, had significantly accumulated and were higher in SD treated mature fruits compared with that of CK. Furthermore, according to the results of the transcriptome data and weighted gene coexpression correlation network analysis (WGCNA) analysis, phenylalanine ammonia-lyase (PAL3) was considered a key structural gene. The qRT-PCR analysis verified that the PAL3 was highly expressed in SD treated postharvest stored fruits, and was significantly positively correlated with the anthocyanin content. Moreover, we found that other structural genes in the anthocyanin biosynthesis pathway were also upregulated under SD treatment, as evidenced by transcriptome data and qRT-PCR analysis.ConclusionsThe findings suggest that SD treatment promotes the accumulation of substrates necessary for anthocyanin biosynthesis during the fruit ripening process, and activates the expression of anthocyanin biosynthesis pathway genes during the postharvest storage period. This is especially true for PAL3, which co-contributed to the rapid accumulation of anthocyanin. The present study provides a theoretical basis for the postharvest quality control and water-saving utilization of blood orange fruit.

Ultrasound synergistic slightly acidic electrolyzed water treatment of grapes: Impacts on microbial loads, wettability, and postharvest storage quality

Microbial contamination is the principal factor in the deterioration of postharvest storage quality in grapes. To mitigate this issue, we explored a synergistic treatment which combines ultrasound (US) and slightly acidic electrolyzed water (SAEW), and rigorously compared with conventional water cleaning (CW), exclusive US treatment, and standalone SAEW treatment. The US + SAEW treatment proved to be markedly superior in reducing total bacterial, mold & yeast counts on grapes. Specifically, it achieved reductions of 2.23 log CFU/g and 2.76 log CFU/g, respectively, exceeding the efficiencies of SAEW (0.78, 0.75), US (0.58, 0.65), and CW (0.24, 0.46). The efficacy of this synergistic treatment is attributed to the ultrasound removal of the wax layer on grape skins, which transitions the skin from hydrophobic to hydrophilic. This alteration increases the contact area between the grape surface and SAEW, thereby enhancing the antimicrobial efficacy of SAEW. From a physicochemical quality standpoint, the US + SAEW treatment exhibited multiple advantages. It not only minimized weight loss, color deviations, polyphenol oxidase activity and malondialdehyde synthesis in comparison to CW-treated samples but also preserved firmness, sugar-acid ratio and the activities of key enzymes including phenylalanine ammonia-lyase, superoxide dismutase and catalase, and thus maintaining high levels of total phenolics, total ascorbic acid, total anthocyanins, and antioxidants. Consequently, US + SAEW treatment put off the times of decay onset in grapes by 12 days, outperforming both SAEW (8) and US (4) in comparison to CW. These results highlight the potential of US + SAEW as an effective strategy for maintaining grape quality during their postharvest storage period.

Morpho-phylogenetic identification and characterization of new causal agents of Fusarium species for postharvest fruit rot disease of muskmelon in northern Thailand and their sensitivity to fungicides.

A significant global problem affecting muskmelon (Cucumis melo L.) is fruit rot caused by phytopathogenic fungi, which results in unsaleable products and substantial financial losses. In 2022 and 2023, fruit rot on muskmelon was found during the postharvest storage period in Phayao Province of northern Thailand. The aim of the current study was to isolate the species of fungi causing the fruit rot lesions. Out of the rot lesions on muskmelons, nine fungal isolates were received. All isolates of fungi were identified through a combination of morphological characteristics and molecular analyses. Based on their morphological traits, all isolated fungal isolate was assigned to the genus Fusarium. All the fungal isolates were determined to belong to the Fusarium incarnatum-equiseti species complex through multi-gene phylogenetic analysis employing the calmodulin (cam), RNA polymerase second largest subunit (rpb2), and translation elongation factor 1-alpha (tef1-α) genes. These isolates were identified as F. compactum (SDBR-CMU483), F. jinanense (SDBR-CMU484, SDBR-CMU485, and SDBR-CMU486), F. mianyangense (SDBR-CMU487 and SDBR-CMU488), and F. sulawesiense (SDBR-CMU489, SDBR-CMU490, and SDBR-CMU491). Moreover, pathogenicity tests were subsequently carried out, and the results indicated that all fungal isolates caused symptoms of fruit rot on inoculated muskmelon fruits. Notably, this result was consistent with the symptoms observed throughout the postharvest storage period. In the fungicide screening test, all fungal isolates showed sensitivity to copper oxychloride. However, all isolates showed insensitivity to benalaxyl-M + mancozeb, carbendazim, mancozeb, and metalaxy. To the best of our knowledge, the present study is the first to identify F. compactum, F. jinanense, and F. mianyangense as new causative agents of muskmelon fruit rot in Thailand and other regions globally. This is also the first report of postharvest fruit rot on muskmelons caused by F. sulawesiense in Thailand. Furthermore, the fungicide screening results indicate that fungicide resistance can be beneficial in developing potential management strategies against postharvest fruit rot disease of muskmelon caused by these four pathogenic Fusarium species.

Optimal chlorophyll extraction conditions and postharvest stability in Moringa (M. Oleifera) leaves

This study aimed to assess the optimal conditions for the extraction of chlorophyll and the stability of chlorophyll with postharvest storage period in Moringa Oleifera leaves harvested in 3 different years for its preservation and lifespan. For this purpose, chlorophylls a (Chla) and b (Chlb) were extracted from the leaves using acetone, methanol, N, N-dimethylformamide (DMF), and the ‘green’ solvent (ethanol). In addition, the chlorophylls were extracted under various conditions, including temperatures (4, 25, and 45 °C), and times (10, 30, and 60 min) from dry leaves that were harvested in different years (2020, 2021, and 2022). The results showed that the Chla content extracted exceeded that of Chlb in the four solvents in all temperatures and extraction times, except for acetone and ethanol extracts under 45 °C at 30 and 60-min extraction times in samples harvested in 2022. An increase in extraction time and temperature resulted in higher chlorophyll content. Overall chlorophyll content decreased with the increasing postharvest storage period, particularly in methanol and ethanol extracts. The Chlorophyll Stability Index showed that chlorophyll is stable in moringa, such that the chlorophyll content obtained in a 2-year postharvest storage period samples was also found to be high. In general, the chlorophyll obtained from this study was found to be compatible with what is used in the industrial market. This suggests that the chlorophyll from moringa is stable and can be considered a major source of chlorophyll.

Current trends and prospects of apple breeding (<i>Malus</i> Mill) in Russia: review

In the Russian Federation, 506 varieties of apple trees are approved for use (10 included in 2023) with different periods of consumer ripeness of the fruit. The activities of breeding institutions have made it possible to improve the assortment of apple trees, while it is necessary to obtain new varieties of apple trees with a complex of adaptive traits and commercial and consumer qualities of fruits that ensure stable fruiting, productivity in unstable climatic conditions, as well as a long period of post-harvest storage of fruits; and, accordingly, determining the profitability of using these varieties in production plantings. In accordance with the increasing requirements for varieties, new breeding achievements must surpass previous analogues in a set of valuable breeding traits, which confirms the need to improve breeding programs. The key areas of apple tree selection are increasing winter hardiness, drought resistance, disease resistance, improving the biochemical composition and shelf life of the fruit, and columnar crown shape. Intensification of the selection process is necessary to reduce the time to obtain a new variety and its production development; in connection with this, marker-mediated selection is a promising direction for accelerating the selection process. The review article presents data on the work of scientific institutions where apple tree selection is carried out. The results of many years of work by leading research organizations of the Russian Federation in the field of apple breeding are covered. Data on scientific institutions, depending on their territorial location, are sorted by regions of admission of the State Register of Selection Achievements approved for use. The results of many years of work of leading research organizations, the main directions of apple breeding are covered, data on the use of modern methods for studying breeding material in research institutions are provided, and approaches to the early selection of economically valuable genotypes are presented. The analytical review is supplemented with information on ways to expand the genetic variability of hybrid offspring. The creation of varieties with a high level of adaptability, commercial and consumer characteristics of fruits will contribute to the further improvement of the apple tree assortment in the Russian Federation.

Role of Postharvest Oxalic Acid Treatment on Quality Properties, Phenolic Compounds, and Organic Acid Contents of Nectarine Fruits during Cold Storage

Due to the soft texture of the nectarine fruit, there are difficulties in long-term storage of this fruit. Therefore, it is of great importance to extend the postharvest storage period of this fruit species. In this study, the effect of postharvest OA (Oxalic acid) applications (0, 0.5, 1 and 1.5 mM) on the quality and biochemical contents of nectarine fruits was investigated. On the 40th day of storage, 1.5 mM OA doses reduced weight loss (1.96%) and fruit flesh firmness (36 N) by approximately 44% and 20%, respectively, compared to the control group. The most effective dose in reducing the respiratory rate was again 1.5 mM OA. The 1 mM OA dose was determined to prevent the decay rate approximately by 16% compared to the control group. Organic acid contents showed a continuous decreasing trend during storage and malic acid was determined to be the dominant acid in nectarine fruits. At the end of storage, it was determined that a 1.5 mM OA dose prevented the decrease in malic acid content approximately 35% more than the control group. Chlorogenic acid and rutin were detected at a higher rate than other phenolics. It was observed that 1.5 mM OA dose prevented the breakdown of chlorogenic acid and rutin compounds more so than other doses during storage. In this study, it was determined that a 1.5 mM OA dose especially protected the quality properties and biochemical contents of nectarine fruits in the cold storage more than the control group.

Tissue-specific modulation of functional stress responsive proteins and organic osmolytes by a single or dual short-term high CO2 treatment during long-term cold storage Autumn Royal table grapes

Plant cell response to damage from environmental stressors that cause dehydration involves stress-related proteins and osmotically active compounds whose constitutive levels increase in association with the tolerance response mechanism. In table grape postharvest scope, the application of a second 3 d 20 kPa CO2 treatment significantly reduced the incidence and severity of long-term cold postharvest storage disorders in Autumn Royal cv. counteracting ultrastructural cell damage and restraining intracellular and membrane oxidative stress. In this sense, it may be of relevance to postharvest quality to know how this dual short-term high CO2 treatment modulates the cell stress responsive defense strategies, and whether these are tissue-dependent and timing-regulated. In this work, we studied the differential profile of protective osmolytes proline, glycine betaine, γ-aminobutyric acid and trehalose in the berry tissues. Likewise, we assessed the temporal and spatial expression and accumulation patterns of the thaumatin-like protein (VviTL1, VviOsmo) and dehydrin (VviDHN1a, VviDHN4, VviDHN2, VviDHN2D) isoforms in the whole berry tissues and rachis of cv. Autumn Royal table grapes during long-term cold storage period and evaluated the profile-shift by CO2 treatments. Their subcellular localization in the pericarp tissues was also determined by immunocytochemical transmission electron microscopy (TEM). The results showed that the cold-drought defense strategies activated by the short-term high CO2 are dose-dependent, tissue-specific and transcriptionally timing-regulated during long-term postharvest cold storage period in table grapes. The results also showed that the more short-term high CO2 treatment is applied to Autumn Royal grapes, the more microstructural evidence there is of enhanced tolerance to storage disorders in terms of thicker and denser cell wall that could contribute to restrain swelling, dehydration and osmotic stress.

Metabolomic analysis of strawberries at different maturities according to postharvest storage period

The appearance and quality of strawberries quickly changes during maturity and postharvest storage. However, there is limited information on the changes in quality-related metabolites of strawberries at different maturities during postharvest storage. This study investigated the changes in strawberry metabolite profiles and general quality characteristics, including color, soluble solids content (SSC), titratable acidity (TA), SSC/TA ratio, and firmness at different maturities (50%, 75%, and 100%) stored for 12 d, and evaluated their associations. The surface color changed to red, SSC/TA increased, and firmness slightly increased during postharvest storage. Moreover, there were changed metabolite profiles related to strawberry quality, including sugars, acidic compounds, lipids, flavonoids, phenolic acid derivatives, and tannins. In particular, anthocyanins and cinnamic acid derivatives significantly accumulated with increasing maturity and storage, whereas catechin and condensed tannin decreased. The strawberry metabolomic pathway related to maturity and postharvest storage was proposed based on these metabolites, and it correlated with general quality characteristics. Although changes in volatile compounds, sensory quality, and functional properties were not investigated, these results in this study facilitate a better understanding of the changes in quality-related metabolites of strawberries according to maturity and postharvest storage period.

Prospects of plant-derived metallic nanopesticides against storage pests - A review

The desire to increase agricultural productivity and to alleviate food losses caused by insects during post-harvest storage periods has augmented the rampant use of unsafe chemo-synthetic pesticides. The elevated health risks on human or domestic animals and environmental pollution by chemo-pesticides have shifted the focus of getting eco-friendly pesticides from biological entities. Research on the nanotechnological application in agriculture has become popular and promising. The diversity among plant species as well as the possession of different insect-specific bioactive compounds makes them the favoured choice for exploring active ingredients, and the application of nanoscience has facilitated the development of effective nano-biopesticides. Varieties of phytochemical groups act as reducing- and stabilizing agents during the biosynthesis of metallic nanoparticles that would be operated as nanobiopesticides. Moreover, green synthesis of metallic nanoparticles or nano-conjugates, especially silver nanoparticles have been experimentally proven successful in controlling insects of stored food products. This review compiles phyto-derived metallic nanoparticles' potential and effectiveness against storage insects, and the analysis will augment research in designing and promoting the development of eco-friendly agrochemicals.

Identification and Characterization of Fusarium Species Causing Watermelon Fruit Rot in Northern Thailand.

Fruit rot caused by phytopathogenic fungi is one of the major diseases affecting watermelons (Citrullus lanatus) around the world, which can result in unmarketable fruits and significant economic losses. Fruit rot was observed on watermelons throughout the postharvest storage periods in Phayao Province, northern Thailand in 2022. For the present study, a total of ten fungal isolates were isolated from the rot lesions of watermelons. All obtained fungal isolates were then characterized in terms of their pathogenicity. The results indicated that only four fungal isolates caused rot disease with similar symptoms during the postharvest storage period. Based on their morphological characteristics, these four fungal isolates were identified as belonging to the genus Fusarium. Using multi-gene phylogenetic analyses with a combination of the translation elongation factor 1-alpha (tef-1), calmodulin (cam), and RNA polymerase second largest subunit (rpb2) genes, the fungal isolates were subsequently identified as Fusarium compactum and F. paranaense. Taken together, the results of this study indicate that F. compactum and F. paranaense cause fruit rot disease in watermelons. To the best of our knowledge, this is the first study to report F. compactum and F. paranaense as novel pathogens of watermelon fruit rot both in Thailand and elsewhere in the world.

One-Step Synthesis of Poly(L-Lactic Acid)-Based Soft Films with Gas Permselectivity for White Mushrooms (Agaricus bisporus) Preservation.

Proper packaging can extend the shelf life and maintain the quality of mushrooms during storage. The purpose of this study is to investigate the preservation of Agaricus bisporus using copolymer-modified poly (L-lactide-co-butylene fumarate) and poly (L-lactide-co-glycolic acid) (PLBF and PLGA) packaging. Shelf life and quality were evaluated over 15 days of storage of Agaricus bisporus at 4 ± 1 °C and 90% relative humidity, including weight loss, browning index (BI), total phenolics (TP), ascorbic acid (AA), malondialdehyde content (MDA), electrolyte leakage rate (EC), and superoxide dismutase (SOD) and catalase (CAT). The results showed that mushrooms packaged in PLBF films exhibited better retention in BI, TP, and AA than those with PLLA, PLGA, or polyethylene (PE) films. They can reduce the rate of weight loss, EC, and MDA, which in turn increases the activity of SOD and CAT. PLBF and PLGA have substantially improved flexibility in comparison with PLLA. They also significantly reduced oxygen (O2) and carbon dioxide (CO2) permeability and changed the gas permeability ratio. These positive effects resulted in the effective restriction of O2 and CO2 in these packages, extending the post-harvest storage period of white mushrooms.

Post-harvest quality changes and shelf-life determination of washed and blanched sugar kelp (Saccharina latissima)

Sugar kelp (Saccharina latissima) is a native European brown macroalga with the potential to become a vital part of the green transition of the food industry. Knowledge of the sugar kelp shelf-life is essential to designing the food supply chain to ensure safe and high-quality food. Establishing a single-compound quality index (SCQI) of freshness would be useful for the industry. However, information is currently lacking on how different post-harvest treatments affect the shelf-life of sugar kelp, even though it is important knowledge for manufacturers, authorities and consumers. The objective of this study was to establish the shelf-life of refrigerated sugar kelp following five post-harvest treatments and evaluate the effect of these treatments on changes in quality attributes (sensory, microbial, chemical and physical) during storage to select the SCQI. The post-harvest treatments included washing in sea water, washing in potable water, blanching for 2 min in sea water or potable water and untreated sugar kelp. Based on sensory analysis, the refrigerated (+ 2.8°C) shelf-lives for sugar kelp from all treatments were seven to 9 days. The end of the sensory shelf-life correlated with the development of >7 log (CFU g−1) aerobic viable counts, suggesting this attribute can be used as a SCQI to evaluate the shelf-life of sugar kelp. The microbiota was dominated by putative spoilage organisms from the Pseudoalteromonadaceae and Psychromonadaceae families. Untreated and washed sugar kelp continued to respire and consume carbohydrates up to 5 days post-harvest, indicating respiration rates may be used to determine freshness of non-blanched kelp. Favorable organoleptic properties, e.g., sweetness and umami, decreased during storage and coincided with a reduction in water-soluble mannitol and free glutamic acid. Both blanching treatments changed texture and color and reduced iodine and vitamin C contents while retaining components such as fucoxanthin, chlorophyll a and β-carotene. This study provides crucial documentation of quality changes during the post-harvest storage period of sugar kelp, including information about sugar kelp spoilage and nutrient changes, which would facilitate the development of best practices for manufacturers using sugar kelp in their production of food.

Effect of The Storage Period on the Antioxidant Properties of Different Watermelon Cultivars Grown in Tunisia

Postharvest storage conditions frequently affect nutritional quality of fruits and vegetables. Temperature and storage duration are the most important factors to extend shelf life and maintain quality of fresh watermelon. This study was conducted to determine the changes in the antioxidant properties of watermelon during storage. Fruits of the watermelon cultivars were harvested and stored at 5ºC for a period of 15 days. During storage antioxidant contents (lycopene and total phenolics) and total antioxidant activity were evaluated. The objective of this work was to determine the content of the antioxidant properties in different watermelon genotypes at four different postharvest storage periods (0, 5, 10 and 15 days). Furthermore, the nutritional quality is strongly influenced by the storage period. The cv Mahdia was the most suitable for extended storage periods.

Evaluation of the Egg Predator Blattisocius tarsalis (Mesostigmata: Blattisociidae) for the Biological Control of the Potato Tuber Moth Tecia solanivora under Storage Conditions

Tecia solanivora is the most prevalent pest causing damage to potato crops in fields in the Canary Islands, but even more so in the postharvest storage period. However, currently, there are no authorised chemical insecticides for potato storage facilities. Analysis of the viability of the predator mite Blattisocius tarsalis as a biological control agent for this moth was carried out. A study of the temperature effect showed B. tarsalis maintains predatory capacity in the range of 10–27 °C. Though predatory activity increases with temperature, no differences in mortality rates were observed between 10 and 20 °C (33.52 ± 2.44 and 40.14 ± 3.54% efficacy rate, respectively), nor between 25 and 27 °C (59.26 ± 4.59 and 75.19 ± 4.64% efficacy rate, respectively). Under microcosm conditions, at low pest infestation (10 eggs), B. tarsalis achieved the highest mortality of eggs at a density of 5 mites, with an efficacy rate of 91.67 ± 8.33%. At high infestation levels (50 eggs), maximum mortality was achieved with a density of 10 mites and efficacy of 98.52 ± 1.48%. The choice-assay showed no preference of B. tarsalis between T. solanivora and Phthorimaea operculella, suggesting this mite could be useful in mixed infestations of potato moths. The results show B. tarsalis is a very good candidate as a control agent in storage conditions and even in mixed infestations of T. solanivora and P. operculella.