Postharvest Storage Quality Research Articles

Optimizing chlorine dioxide treatment for enhanced post-harvest storage quality of Toona Sinensis.

This study investigated the impact of chlorine dioxide (ClO2) treatment on the storage quality of Toona sinensis after harvesting. Toona sinensis samples treated with different concentrations (0.2, 0.4, 0.8, 1.6 mg/L) of chlorine dioxide and stored at (4 ± 1) °C, with sampling test every 2nd day. The changes in sensory, nutritional, and chlorine dioxide residues of T. sinensis were checked regularly. Results revealed that moderate (0.4~0.8 mg/L) chlorine dioxide concentrations maintained sensory quality, inhibited T. sinensis weight loss, slowed flavonoid and vitamin C content depletion, reduced nitrite content, and enhanced superoxide dismutase activity. The chlorine dioxide resides in T. sinensis were below the national standards (<2.0 mg/kg; GB 5009.244-2016). Overall, 0.4~0.8 mg/L chlorine dioxide treatment showed optimal effects on T. sinensis, providing a scientific basis for extended storage and preservation of T. sinensis.

Effects of Chlorine Dioxide on the Postharvest Storage Quality of Fresh-Cut Button Mushrooms (Agaricus bisporus)

The application of chlorine dioxide (ClO2) in microbial safety and quality maintenance of fresh produce has received extensive attention. Fresh-cut button mushrooms (Agaricus bisporus) are prone to spoilage, resulting in a short shelf-life. In this study, ClO2 treatment was used to preserve fresh-cut button mushrooms, and its effect on maintaining the postharvest quality was investigated using sensory evaluation, weight loss, color, firmness, respiration rate, electronic-nose (E-nose) analysis and microbial analysis. During the 8 d storage, both the 50 and 100 mg·L−1 ClO2 treatment reduced the aerobic bacteria count on the surface of fresh-cut button mushrooms. However, the results showed that the 50 mg·L−1 ClO2 treatment but not the 100 mg·L−1 ClO2 treatment significantly inhibited the deterioration of comprehensive quality. The 50 mg·L−1 ClO2 treatment maintained the high sensory evaluation and pleasant volatile odor of fresh-cut button mushrooms as well as reduced the decreasing of fresh weight and firmness. Contrary to expectations, the application of ClO2 treatment showed worse appearances in color (lower L*, higher a*, b* and browning index) of fresh-cut button mushrooms. Significant differences were observed between CK and ClO2-treated groups from day 0 to day 6, while there were no significant differences of a*, b* and browning index between CK and the 50 mg·L−1 ClO2 treatment at the end of storage (on day 8). In conclusion, the 50 mg·L−1 ClO2 can maintain the good quality of fresh-cut button mushrooms.

Synergistic variation in abscisic acid and brassinolide treatment signaling component alleviates fruit quality of ‘Shine Muscat’ grape during cold storage

Grape fruit are harvested in the late summer or early fall and need to be stored at low temperatures to prevent enfeeblement and prolong their shelf-life. This study aimed to determine the effects of abscisic acid (ABA), brassinolide (BR) and ABA + BR (ABR) treatment on the berry quality of ‘Shine Muscat’ under low temperatures. ABA and BR maintained fruit appearance, cellular structure, weight, firmness. ABR treatments reduced the loss of fruit aroma. Furthermore, the transcriptome and metabolome analysis revealed that ABA, BR, and ABR treatments maintained the quality of fruits during the low temperatures period by influencing chlorophyll metabolism, carotenoid metabolism, flavonoid metabolism, unsaturated fatty acid, and terpene metabolism. These findings identify key genes and metabolites for ABA and BR-induced maintenance of grape fruit quality during cold storage, expanding our understanding of postharvest storage quality maintenance of grape fruit at the transcript and metabolic levels.

Impacts of Fruit Frosting Coverage on Postharvest Softening of Prunes under Vibration Stress

The surface of prune fruit has a thick layer of frosting, which is easily damaged and lost during prunes harvest or postharvest handling, and there is no clear information on the effect of prune surface frost on postharvest storage quality. To investigate the effect of fruit frosting on the softening of prune fruits during storage under vibration stress, prunes were divided into three grades according to fruit frosting in this study and were vibrated for 8 h at a frequency of 5 Hz at 4 °C; then, samples were selected once every 8 d. The results showed that the heavy fruit frosting (HFF) group maintained higher hardness (21.47%), L* (20.85%), and total soluble solids (12.79%) levels at the end of storage and inhibited cell wall-modifying enzyme activities (polygalacturonase, pectin methylesterase, glycosidase, β-glucosidase, and cellulase) compared to frosting-less fruit (FF) group. This group also showed improved expression of key cell wall-modification genes (ADPG2, PME31, CESA1, BGAL3, XTH33, BGLU41) as well as chelate-soluble pectin (72.11%), Na2CO3-soluble pectin (42.83%), and cellulose (36.89%) solubilization and maintained lower water-soluble pectin (34.23%). Microscopic observations showed that the fruit frosting could delay the dissolution of pectin components and protect the cell wall structure. In summary, fruit frosting can effectively inhibit fruit softening and maintain fruit quality.

Storage temperature affects metabolism of sweet corn

Temperature is one of the critical factors affecting the postharvest storage quality of sweet corn, but effects of storage temperatures have not been elucidated at the molecular level. In this study, the effects of storage at 0 °C, 4 °C and 20 °C, on quality and associated effects on the transcriptome and metabolome were investigated. Compared with storage at 20 °C, cobs stored at 0 °C and 4 °C had up-regulated expression of genes associated with cell wall disassembly (PG, PE, BMY, β-Gal) and down-regulated expression of genes involved in lignin synthesis, the up-regulation of SPP, SPS and SUS involved in sucrose synthesis, and the down-regulation of IN, FK, HXK and PFK involved in sucrose catabolism. Most of the genes involved in ethylene biosynthesis and signaling were inhibited at 0 °C, except for ERFs, while abscisic acid synthesis and signal transduction were most active at this temperature. Near-freezing temperature also maintains the integrity of the cell membrane by inhibiting the expression of PLD, PLC and LOX, which encode membrane lipid-degrading enzymes. Metabolomics and combined analysis showed that the contents of lysophospholipid, glutathione and L-ascorbic acid in sweet corn increased at low temperatures. These results provide insight into the effects of low temperatures on sweet corn quality.

Spore discharge associated with physiological quality variations and energy metabolism in harvested Lentinula edodes

As a sign of mushroom maturity, spore discharge continues accelerating in postharvest Lentinula edodes. However, the relationship between spore discharge quantity and both physiological quality and energy metabolism remains unclear. In this study, spore discharge intensity, the number of spores discharged per unit mass of fruiting body per unit time, was introduced to analyze the variations in physiological quality attributes and energy metabolism associated with spore discharge in harvested Lentinula edodes. The results demonstrated a correlation between increased spore discharge intensity and deteriorating weight loss, firmness, and browning of the fruiting bodies. Moreover, a positive relationship was observed between spore discharge intensity and mannitol, an osmotic substance released alongside spores. Mannitol metabolism is linked to glycolysis, suggesting that the accumulation of mannitol may enhance spore discharge. Significant correlations were identified between the total amount of spore discharge and H+-ATPase activity, as well as energy charge, which proved that higher levels of energy metabolism may promote spore discharge. Energy depletion was responsible for the deterioration in the physiological quality during this period. Collectively, a substantial amount of spore discharge needs to be supported by adequate osmotic substances and energy levels, and this result may provide a new perspective on the preservation of edible mushrooms. Delaying the peak of spore release and inhibiting the spore discharge intensity may be directions for maintaining the postharvest storage quality of edible mushrooms.

Chitosan/gelatin coating loaded with ginger essential oil/β-cyclodextrin inclusion complex on quality and shelf life of blueberries

Blueberries are highly susceptible to fungal pathogens and oxidative deterioration due to their thin epidermal layer, which can be mitigated by applying a natural polymer-based antimicrobial coating to their surface. This study aimed to develop a chitosan/gelatin-based antimicrobial coating utilizing ginger essential oil (GEO) to extend the postharvest quality of blueberries. To ensure GEO's stability within the coating, it was initially encapsulated with β-cyclodextrin (β-CD) using the inclusion complexation technique. The GEO/β-CD inclusion complex (IC) formed rhomboidal shapes with high encapsulation efficiency and small particle sizes. When the optimized GEO/β-CD IC was incorporated into the chitosan/gelatin polymer solution, it significantly increased surface hydrophobicity and free radical scavenging activity, and suppressed the growth of three selected fungi, namely Botrytis cinerea, Penicillium italicum and Alternaria alternaria. The results of postharvest storage quality revealed that blueberry samples coated with CH/Gel-GEO/β-CD IC-5 effectively maintained the quality of blueberries by decreasing weight loss and decay incidence, and regulating anthocyanin and other oxidation-related enzyme activities compared to the control group during 16 days at 25 °C and 40 days at 4 °C storages. In conclusion, it can be stated that CH/Gel-GEO/β-CD composite coating can be a promising technology to address the drawbacks of blueberry preservation.

Improving blueberry cold storage quality: the effect of preharvest hexanal application on chilling injuries and antioxidant defense mechanisms.

Blueberries are vulnerable to chilling injury (CI). This can lead to limited longevity when they are subjected to cold storage conditions. This study investigated the effectiveness of a preharvest spray containing 0.02% hexanal in reducing CI and improving the postharvest storage quality of 'Star' and 'Biloxi' blueberries. The blueberries were stored for a period of 5 weeks at 2 °C and in 90% relative humidity (RH). The findings revealed that the preharvest hexanal spraying of both cultivars delayed senescence by mitigating CI, as evidenced by the bolstering of the antioxidant defense system through increased superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT), and phenylalanine ammonia lyase (PAL) enzyme activity. The treated fruit also maintained elevated levels of total phenol content (TPC), total flavonoids (TFC), and vitamin C, demonstrating enhanced free radical scavenging capacity (FRSC), while exhibiting reduced polyphenoloxidase (PPO) activity, and reduced malondialdehyde (MDA), and H2O2 content in comparison with the control group. The preharvest hexanal treatment also suppressed fruit softening by maintaining greater firmness and higher membrane stability index (MSI) scores, inhibiting the activity of polygalacturonase (PG), pectinmethylesterase (PME), xylanase, and α-amylase, and reducing microbial counts (MC) and incidence of decay (DI) in comparison with the control. Preharvest hexanal treatment also improved the overall storage quality by reducing weight loss, total soluble solids (TSS), pH, and the TSS/acid ratio, while increasing titratable acidity (TA) in comparison with the control during cold storage. The findings suggest that hexanal, as a preharvest application, delays senescence effectively and preserves overall quality by enhancing cold tolerance through antioxidant defense mechanisms in blueberry storage under cold conditions. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of ozone treatment on phenylpropanoid metabolism in harvested cantaloupes.

Phenylpropanoid metabolism plays an important role in cantaloupe ripening and senescence, but the mechanism of ozone regulation on phenylpropanoid metabolism remains unclear. This study investigated how ozone treatment modulates the levels of secondary metabolites associated with phenylpropanoid metabolism, the related enzyme activities, and gene expression in cantaloupe. Treating cantaloupes with 15mg/m3 of ozone after precooling can help maintain postharvest hardness. This treatment also enhances the production and accumulation of secondary metabolites, such as total phenols, flavonoids, and lignin. These metabolites are essential components of the phenylpropanoid metabolic pathway, activating enzymes like phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, 4CL, chalcone synthase, and chalcone isomerase. The results of the transcriptional expression patterns showed that differential gene expression related to phenylpropanoid metabolism in the peel of ozone-treated cantaloupes was primarily observed during the middle and late storage stages. In contrast, the pulp exhibited significant differential gene expression mainly during the early storage stage. Furthermore, it was observed that the level of gene expression in the peel was generally higher than that in the pulp. The correlation between the relative amount of gene changes in cantaloupe, activity of selected enzymes, and concentration of secondary metabolites could be accompanied by positive regulation of the phenylpropanoid metabolic pathway. Therefore, ozone stress induction positively enhances the biosynthesis of flavonoids in cantaloupes, leading to an increased accumulation of secondary metabolites. Additionally, it also improves the postharvest storage quality of cantaloupes.

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.

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.

Transcriptome Analysis of the Preservation Effect of Three Essential Oil Microcapsules on Okra

Cinnamon (Cinnamomum sp.) essential oil microcapsules, oregano (Origanum sp.) essential oil microcapsules, and oregano–thyme (Thymus sp.) essential oil microcapsules are rarely used in the postharvest preservation treatment of okra (Abelmoschus esculentus L.). The mechanism of these three essential oil microcapsules on the postharvest preservation of okra is also not yet well understood. In this study, fresh okra was preserved by three kinds of essential oil microcapsules (cinnamon essential oil microcapsules, oregano essential oil microcapsules, and oregano–thyme essential oil microcapsules). The effect of essential oil microcapsules on the postharvest storage quality of okra was discussed. We also used RNA-Seq to preliminarily explore the mechanism of oregano–thyme essential oil microcapsules on the pre-harvest storage quality of okra. The results showed that the three kinds of essential oil microcapsules could maintain the high sensory evaluation quality and firmness of okra, slow down the increase in respiratory intensity, slow down the total number of colonies on the fruit surface, and slow down weight loss. Through analysis, it was found that the effect of oregano–thyme essential oil microcapsules was remarkably better than that of cinnamon essential oil microcapsules and oregano essential oil microcapsules. The preservation mechanism of oregano–thyme essential oil microcapsules on postharvest okra was preliminarily elucidated by RNA-Seq. This study provides a certain basis for a follow-up study of essential oil microcapsules in the preservation of okra.

Effect of exogenous melatonin on postharvest storage quality of passion fruit through antioxidant metabolism

This study investigated the effect of melatonin (MT) on postharvest storage quality of passion fruit. Passion fruits were treated with four different concentrations of MT solutions (100, 200, 300 and 400 μmol/L) for 30 min and stored for 8 days. Compared with the control, the optimal MT concentration (200 μmol/L) treatment significantly reduced the shrinkage index, browning index, weight loss, ethylene production, and respiration rate, and delayed the decline of firmness, total soluble solids (TSS), and color, thus maintaining the quality of postharvest fruits. Exogenous MT enhances antioxidant activity and reduces fruit oxidative damage by inhibiting the increase in pericarp cell membrane permeability, malondialdehyde (MDA) content, maintaining high ascorbic acid (AsA), total phenolics, and flavonoids content, and increasing superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and polyphenol oxidase (PPO) activities. These findings suggest that postharvest exogenous application of MT is effective in maintaining passion fruit quality and delaying senescence.

Polypropylene packaging alleviates the quality deterioration of Lentinus edodes through antioxidant system and phenylpropane pathway

Lentinus edodes (L. edodes) is a popular edible mushroom, which is very easy to rot and deteriorate after harvest. The quality of L. edodes were significantly affected by different packaging materials. Hence, polypropylene (PP) or polyethylene (PE) packaging were employed to explore the effects and underlying mechanisms on the post-harvested quality of L. edodes. Compared with PE packaging, PP packaging could maintain good storage quality and membrane integrity of L. edodes by reducing oxidative damage, which might be related to the significantly decreased relative electrolyte leakage and malondialdehyde content at the later stage of storage. Also, PP packaging could improve the antioxidant ability and inhibit the production of H2O2 by the decreased catalase and increased superoxide dismutase content. Phenylalanine ammonia lyase, phenylalanine ammonia lyase and cinnamaldehyde dehydrogenase, as the key enzymes in the metabolic pathway of phenylpropane, increased at the later storage of PP-packaged L. edodes. It helped the synthesis of phenolic substances and lignin accumulation. These results indicated PP packaging could be an effective material for maintaining the postharvest storage quality of L. edodes, which might be related to the antioxidant system and phenylpropane pathway.

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.

Harvest maturity stage affects watercore dissipation and postharvest quality deterioration of watercore 'Fuji' apples

Watercore 'Fuji' apples, with their special watercore shape and unique flavor and texture, are a very popular specialty fruit in the Asian markets. However, watercore disappearance and quality deterioration of apples during postharvest storage are serious problems. In this study, we compared the differences among three harvest maturity stages of apples in watercore dissipation and fruit quality deterioration. In this study, the physiochemical attributes (visual quality, watercore incidence, and firmness), flavor substances (TSS content, TA content, and TSS/TA), aroma volatiles, and cellular structure were analyzed in 'Fuji' apple fruits of low maturity (LM) at early harvest stage, medium maturity (MM) at mid harvest stage, and high maturity (HM) at late harvest stage, during a cold storage at 0 ± 1 °C for 120 d. The results showed that harvest maturity stage had a significant effect on postharvest storage quality parameters of watercore 'Fuji' apples. Specifically, L*, b*, firmness, and TA values of the flesh decreased significantly from the LM to the HM levels. However, the watercore incidence of apples significantly increased from LM to HM levels. Moreover, the parameters including L*, b*, firmenss, TA, and watercore incidence of apples with different harvest maturity stages gradually decreased as the storage time increased. In contrast, the TSS, TSS/TA, and a* values showed an increasing trend from LM to HM apples. In particular, the TSS tended to increase first and decrease after 60 d of storage. Moreover, the microstructure and cellular structure gradually deformed as the structural porosity and cell size decreased from LM to HM apples. Furthermore, the microstructure of the watercore and non-watercore sites is significantly different. Meanwhile, the content of soluble sugars and aroma volatiles increased with the advancing maturity. Non-watercore sites of apples with the same level of maturity contained higher levels of sucrose, fructose, maltose, and sorbitol than watercore sites. Furthermore, the MM apples maintained better sensory qualities during the shelf life after cold storage. Overall, the MM apples showed higher quality and were more acceptable to consumers, which suggested watercore 'Fuji' apples from mid harvest stage showed the optimal harvest-ready maturity for post-harvest long-term cold storage.

Effect of electron-beam generated X-ray irradiation on water status and microstructure of fresh Hericium erinaceus by LF NMR, MRI, SEM and TEM

Water loss poses a threat to the life of postharvest mushrooms. Clarifying the variation of water status in mushrooms and seeking an effective approach to postpone the water loss is of utmost urgency. This study assessed the application of electron-beam generated X-ray (EBGX) irradiation as a novel physical technology to maintain the postharvest storage quality of fresh Hericium erinaceus. Furthermore, the monitoring of changes in water distribution and migration as well as the tissue structure were conducted on irradiated (1.0, 1.5, and 2.0 kGy) samples using low-field nuclear magnetic resonance, magnetic resonance imaging, scanning electron microscopy, and transmission electron microscopy, respectively. Results indicated that the cell compartments of cytoplasm and vacuole constituted the predominant parts among the three water components in H. erinaceus matrix, whereas the water in the vacuole migrated to the cytoplasm after storage. Thereinto, the mushrooms irradiated with 1.0 kGy retarded water migration and contained more water components than those irradiated with 0, 1.5, and 2.0 kGy. Importantly, the dose of 1.0 kGy irradiation had a minimum weight loss of 2.19% and the best retention of color and texture after 9 d of storage. Additionally, low-dose irradiation with 1.0 kGy and 1.5 kGy remarkably improved the physical microstructure of H. erinaceus, while 2.0 kGy irradiation was prejudicial to the tissue structure. Taken together, the dose of 1.0 kGy was the most beneficial in maintaining postharvest quality of H. erinaceus. These findings provide insights into the changes in water status of H. erinaceus and the effects of EBGX irradiation on postharvest quality and deepen our understanding of the underlying mechanism whereby EBGX improves the freshness of H. erinaceus.

Effects of harvest ripeness on storage quality of tomato fruits

For studying the different recovery maturity influence on tomato postharvest storage quality, in different harvest maturity tomato (green ripe period, color-changing period, red period) as experiment material, put it in 3℃ and 28℃temperature storage, and the determination of three different harvest maturity tomato in weightlessness rate, decay rate in the process of storage, reducing sugar content, titratable acid content, lycopene content and the content of ascorbic acid and so on six indicators, according to the fuzzy weight methods to establish comprehensive evaluation index weights, determine the harvest maturity of science. The results showed that under two different temperature environments, the highest comprehensive evaluation index of tomato was 0.6644 and the storage quality was the best. The comprehensive evaluation index of tomatoes harvested in the color-changing period was 0.4709, which was more suitable for storage at 3℃. The comprehensive evaluation index of tomatoes harvested in green ripening period was 0.3919, and the storage quality was relatively poor. Key words: Tomato ；Ripeness； Effect of storage； Quality; Fuzzy weight methods

Ultrasonic synergistic slightly acidic electrolyzed water processing to improve postharvest storage quality of Chinese bayberry

In the postharvest storage of Chinese bayberry, microbial loads and exogenous contaminants pose significant challenges, leading to rapid decay and deterioration in quality. This study introduced a synergistic approach, combining ultrasonics and slightly acidic electrolyzed water (US + SAEW), to enhance the postharvest storage quality of Chinese bayberry. This approach was benchmarked against conventional water washing (CW), standalone ultrasonic (US), and slightly acidic electrolyzed water (SAEW) processing. Notably, compared to CW, the US + SAEW method enhanced iprodione and procymidone removal rates by 69.62 % and 72.45 % respectively, improved dirt removal efficiency by 122.87 %, repelled drosophila melanogaster larvae by 58.33 %, and curtailed total bacterial, mold & yeast growth by 78.18 % and 83.09 %. Furthermore, it postponed the appearance of sample decay by 6 days, compared to 4 days for both US and SAEW alone. From a physicochemical perspective, compared to CW-treated samples, US + SAEW processing mitigated weight loss and color deviations, retained hardness, amplified the sugar-acid ratio, augmented activities of phenylalanine ammonia-lyase, superoxide dismutase, and catalase enzymes, suppressed polyphenol oxidase activity and malondialdehyde synthesis, and preserved total phenolic, anthocyanin, and antioxidant levels. These findings underscore the potential of US + SAEW as a strategic tool to preserve the quality of Chinese bayberry during postharvest storage.

Postharvest Quality Exploration of “Crystal” Grapes in Karst Mountainous Area: Regulatory Effect of High Concentration 1-MCP Fumigation

The comprehensive exploration and thorough understanding of the physicochemical characteristics of “Crystal” grapes in the Karst area of Southwest China can not only produce edible table grapes, but also offer significant theoretical backing for the management of rocky desertification in the Karst area and consequently generate enhanced social and ecological benefits. This study explored the regulatory effect of 1-MCP fumigation on the postharvest storage quality of "Crystal” grapes, aiming to provide some technical support for the development of the grape industry in the Karst mountainous areas. The results indicate that compared with the control group, both the 10.0 and 50.0 μL/L 1-MCP treatment groups effectively inhibited the increase in decay rate, browning rate, shedding rate, and color change of the grapes, significantly inhibited the enhancement of polyphenol oxidase (PPO), peroxidase (POD), and lipoxygenases (LOX) browning-related enzyme activities, improved the superoxide dismutase (SOD) activity of the fruits, hindered the decrease of ascorbic acid (AsA) and polyphenols, delayed the accumulation of malondialdehyde (MDA) content, and significantly postponed the peak period of polygalacturonase (PG) activity in the fruits and the degradation of protopectin to soluble pectin, thereby maintaining desirable texture characteristics. The utilization of 1-MCP for fruit fumigation yielded a heightened overall fragrance, thereby facilitating the emission of terpenes, alcohols, aldehydes, ketone aromatic compounds, and methyl aromatic substances within the fruit. Overall, both the M10 and M50 treatments are equally effective in preserving the storage quality of “Crystal” grapes. Under the condition of ensuring the excellent edible quality of crystal grapes, M2 can extend the shelf life of crystal grapes by about 5 days, and M10 and M50 can extend the storage period of crystal grapes by 10~15 days. Considering the cost, it is recommended that the industry employs a concentration of 10.0 μL/L of 1-MCP for “Crystal” grapes. Simultaneously, this study also provides theoretical support for the ecologically high-quality development of cultivated land in the Karst mountainous area of Guizhou and tree selection.