Long-term Cold Storage Research Articles

Effects of 1-methylcyclopropene on disease resistance of red-fleshed kiwifruit during long-term cold storage and the possible mechanisms

ABSTRACT ‘Hongyang’ kiwifruit is a red-fleshed variety that contains high amounts of nutrients and has a good taste. It is particularly prone to postharvest decay, however, especially at late stages, even under cold storage. The aims of this study were to investigate the effects of 1-methylcyclopropene (1-MCP) on disease resistance in ‘Hongyang’ kiwifruit, and the mechanisms involved in ‘Hongyang’ kiwifruit during long-term cold storage (4 months). The results demonstrated that 1-MCP (0.8 µL/L) effectively reduced fruit decay, which was mainly caused by Phomopsis sp., improved the antioxidant capacity of the fruit by increasing superoxide dismutase and catalase activity, and elevated phenolic compound contents and defence-related enzyme activity. Treatment with 1-MCP also reduced polygalacturonase activity and maintained higher fruit firmness during storage. Collectively these results indicate that 1-MCP treatment maintained the postharvest quality of ‘Hongyang’ kiwifruit, increased antioxidant activity, and reduced the incidence of Phomopsis sp. decay during the late stage of storage.

‘도태랑’ 토마토의 이산화탄소 및 이산화염소 복합 처리에 따른 저장기간 중 품질 향상 효과

Pink-colored tomatoes have higher sugar content than the red-colored tomatoes; however, they are more prone to fruit cracking during cultivation and transportation owing to their lower firmness. Short-term high CO2 and ClO2 gas treatments were used to prevent chilling injury and reduce decay incidence during the cold storage of tomato ‘Dotaerang’ fruits (Solanum lycopersicum Mill. cv. Dotaerang). Harvested tomatoes were treated with 30% CO2, 60% CO2, and 30% CO2 combined with 10 ppm ClO2 (mixed with ambient air) for 3 h, and then stored at 4°C and 20°C. Fruit quality was assessed after storage at 4°C for 14 days and/or transferred to 20°C for 3 days (14+3 days), and 20°C for 13 days. Cold storage and CO2 treatment inhibited the softening process and delayed fruit surface color development and lycopene accumulation in tomatoes (‘Dotaerang’). A high positive correlation was found between the a* value and lycopene content of tomatoes during storage. The chilling injury index was confirmed to be reduced by cold storage and 30% CO2 treatment. In particular, the 30% CO2 combined with 10 ppm ClO2 treatment was highly effective in preventing the decay of tomatoes during long-term cold storage after harvest. These results suggest that pre-storage high CO2 and/or ClO2 treatment and low-temperature storage can effectively extend the shelf life and improve the quality of pink-colored tomato ‘Dotaerang’ fruits.

Antioxidant prevents clearance of hemostatically competent platelets after long-term cold storage.

Cold storage of platelets (PLTs) has the potential advantage of prolonging storage time while reducing posttransfusion infection given the decreased likelihood of bacterial outgrowth during storage and possibly beneficial effects in treating bleeding patients. However, cold storage reduces PLT survival through the induction of complex storage lesions, which are more accentuated when storage is prolonged. Whole blood-derived PLT-rich plasma concentrates from seven PLT pools (n = 5 donors per pool). PLT additive solution was added (67%/33% plasma) and the product was split into 50-mL bags. Split units were stored in the presence or absence of 1 mM of N-acetylcysteine (NAC) under agitation for up to 14 days at room temperature or in the cold and were analyzed for PLT activation, fibrinogen-dependent spreading, microparticle formation, mitochondrial respiratory activity, reactive oxygen species (ROS) generation, as well as in vivo survival and bleeding time correction in immunodeficient mice. Cold storage of PLTs for 7 days or longer induces significant PLT activation, cytoskeletal damage, impaired fibrinogen spreading, enhances mitochondrial metabolic decoupling and ROS generation, and increases macrophage-dependent phagocytosis and macrophage-independent clearance. Addition of NAC prevents PLT clearance and allows a correction of the prolonged bleeding time in thrombocytopenic, aspirin-treated, immunodeficient mice. Long-term cold storage induces mitochondrial uncoupling and increased proton leak and ROS generation. The resulting ROS is a crucial contributor to the increased macrophage-dependent and -independent clearance of functional PLTs and can be prevented by the antioxidant NAC in a magnesium-containing additive solution.

Optimal Harvest Time for Preventing Hot Pepper Seed Browning during Cold Storage Is Associated with Seed Maturity

Chilling injury (CI), which causes seed browning in pepper, may arise following long-term cold storage, and is a major cause of postharvest losses. To explore potential strategies of minimizing the associated postharvest losses, the present study investigated the optimal pepper harvest time that could reduce levels of seed browning, in addition to the relationship between fruit maturity and seed browning. Fruits harvested 15 days after flowering (DAF) were sensitive to cold storage at 4 °C and exhibited 100% seed browning (CI index, 4.0); in contrast, the seed browning rate of fruits harvested 35 DAF was 10% (CI index, 0.4) within 7 days of cold storage. Seed antioxidant activity was higher in seeds harvested at early stages (15 DAF to 20 DAF) than in seeds harvested at later stages (40 DAF to 50 DAF) at the beginning of storage. Pericarps of fruit harvested at 50 DAF exhibited the highest antioxidant activity. Lipoxygenase, catalase, and peroxidase activity, and the expression levels of cell wall-related genes, pectin methylesterase-like protein, and endo-β-1,4-glucanase were higher in seeds of immature fruit harvested 15 DAF than in seeds of mature fruit harvested 35 DAF. The seeds of the fruit harvested 35 DAF were fully developed with the seed coat separated from the endosperm and did not turn brown under low-temperature storage. The lack of seed browning observed in mature fruit under low-temperature storage could be attributed to physical protection provided by the seed coat rather than cold stress resistance conferred by antioxidants.

Quality monitoring method for apples of different maturity under long-term cold storage

As the apple industry has developed, non-destructive testing technology for checking the internal quality of apples based on visible/near infrared spectroscopy has attracted widespread attention. Because apples are usually refrigerated for a long time then sold at a suitable time, a reliable and rapid non-destructive testing method is needed to monitor their internal quality. However, establishing a non-destructive testing model for apples during cold storage is affected by two factors that change over time: the quality from different maturity, and the cell structure of apples during cold storage changes, affecting the scattering of the spectra. A model for predicting the soluble solids content (SSC) and firmness of apples during cold storage was established taking into account the time in cold storage and three levels of maturity at harvest. Two wavelength ranges, visible-near-infrared (Vis-NIR) and long-wave near-infrared (LWIR), were used and regression models established using partial least squares (PLS). LWIR provided a better prediction of SSC and Vis-NIR of firmness. The quality prediction model for apples at three maturity levels during cold storage was highly accurate (SSC: 0.86 < Rp < 0.94, 0.37 < RMSEP < 0.56, firmness: 0.82 < Rp < 0.86, 0.63 < RMSEP < 0.69), and the accuracy of a model combining all samples was satisfactory (SSC: Rp = 0.87, RMSEP = 0.59, firmness: Rp = 0.82, RMSEP = 0.71). This study provides an important theoretical basis for improving the industrial quality inspection and quality classification of apples during cold storage.

Effect of Various Postharvest Treatment on Aroma Volatile Compounds of Blood Orange Fruit Exposed to Chilling Temperature After Long-Term Storage

The aim of this work was to study the composition of aroma volatile compounds (AVCs) of blood orange cv. Moro treated with γ-aminobutyric acid (GABA), methyl jasmonate (MeJA) or methyl salicylate (MeSA) by headspace gas chromatography-mass spectrometry (HS-GC-MS). GABA at 20 and 40 mM was vacuum infiltrated (at 30 kPa for 8 min), and MeJA or MeSA at 50 and 100 μM (vapour treatments) was applied separately at 20 °C for 18 h. AVCs were measured at harvest and at the end of the experiment (150 days at 3 °C + 2 days at 20 °C, shelf life) for all control and treated fruits. The most abundant compound was limonene, followed by β-myrcene and α-pinene. α-Thujene, camphene, β-pinene, n-decane, α-phellandrene, α-terpinene, p-cymene, (E)-β-ocimene, citronellyl acetate and γ-terpinene were affected by treatments after long-term cold storage. The highest and the lowest percentages of limonene were measured in control samples (94.31 ± 1) and fruits treated with 100 μM MeSA (86.68 ± 1), respectively. (E)-Caryophyllene and (E)-ethyl cinnamate were not detected in all samples after 150 days of cold storage. The multivariate statistical analysis revealed that β-myrcene, n-decane, linalool, limonene, trans-limonene oxide, ethyl hexanoate and sabinene were positively correlated with chilling injury. Overall, it can be concluded that these compounds can be used as biological markers related to CI based on the multivariate statistical analyses.

The Effect of the Long-Term Cold Storage and Preservatives on Senescence of Cut Herbaceous Peony Flowers

Recently peonies have become very popular cut flowers. As peony flowering period is short, long term cold storage could assure its prolonged supply and make long distance transport feasible. The effect of dry cold storage, of 8-hydroxyquinoline and nanosilver preservatives on the peony keeping qualities were tested on the most popular cultivar ‘Sarah Bernhardt’. The 12 week storage (0–1 °C) shortened flower longevity by 20%, to 8 days and no vascular blockages in the shoots were observed. However, the presence of callose, not considered as a blocking factor, was evident. The sucrose-containing preservatives with either 8-hydroxyquinoline or nanosilver did not extend the flower longevity but they increased flower diameters in both fresh and stored material. Generally, the soluble total and reducing sugars increased in senescing flowers in both non-stored and stored flowers, and they were lower after storage. The free proline increased ca. 20-times during cold storage and at the end of the vase life it remained generally higher in the stored than in fresh flowers. The level of hydrogen peroxide dropped after 12 weeks storage and its contents at the end of the vase life differed depending on the holding solution. Generally it was lower after storage. Storage increased the catalase activity which remained on higher levels in stored flowers from all holding solutions as compared to freshly cut flowers. A five-fold reduction in the peroxidase activity occurred during storage but its activities at the end of the vase life were similar in stored and non-stored flowers. The effects of nanosilver and 8-hydroxyquinoline were similar.

Effect of Hot-Air and Freeze-Drying on the Quality Attributes of Dried Pomegranate (Punica granatum L.) Arils During Long-Term Cold Storage of Whole Fruit

This study investigated the effect of hot-air and freeze-drying on the physicochemical, phytochemical and antioxidant capacity of dried pomegranate arils during long-term cold storage (7 ± 0.3 °C, with 92 ± 3% relative humidity) of whole fruit over a single experiment. Extracted arils were processed at monthly intervals during 12 weeks of cold storage of whole fruit. After the 12-week storage period, hot-air and freeze-dried arils showed the least (3.02) and highest (23.6) total colour difference (TCD), respectively. Hot-air dried arils also contained 46% more total soluble solids (TSS) than freeze-dried arils. During the storage of pomegranate fruit, total phenolic content (TPC) steadily increased from 20.9 to 23.9 mg GAE/100 mL and total anthocyanin content (TAC) increased from 6.91 to 8.77 mg C3gE /100 mL. Similarly, an increase in TPC and TAC were observed for hot-air (9.3%; 13%) and freeze-dried arils (5%; 5%), respectively. However, the radical scavenging activity (RSA) reduced by 8.5 and 17.4% for hot-air and freeze-dried arils, respectively, after 12 weeks of cold storage. Overall, the parameters such as colour, TPC and TAC as well as the lower degradation in RSA stability during storage showed distinct differences in quality when using the freeze-drying method, which is, therefore, recommended.

High relative humidity (HRH) storage alleviates chilling injury of zucchini fruit by promoting the accumulation of proline and ABA

Abstract In order to investigate the effect of water loss on the different physiological metabolism of zucchini fruit under cold stress after harvest, two cold rooms (4 ℃) with different relative humidities (RH: 74 ± 2 % and 98 ± 2 %) were used for cold storage. The result suggested that high relative humidity (HRH) storage slowed down the increase of weight loss, chilling injury index, malondialdehyde (MDA) content and cell death rate and maintained the postharvest quality such as firmness and flesh color in zucchini fruit. HRH storage promoted the accumulation of proline and induced higher ornithine δ-aminotransferase (OAT), Δ-1-pyrroline-5-carboxylate synthetase (P5CS) enzyme activities and lower proline dehydrogenase (PDH) enzyme activity as compared with low relative humidity (LRH) storage. The content of putrescine (Put) accumulated with the progress of cold damage, which could be delayed by HRH storage due to higher activities of polyamine oxidase (PAO), diamine oxidase (DAO) and ornithine decarboxylase (ODC). Besides, chilling stress induced the biosynthesis of abscisic acid (ABA) during storage and the zucchini fruit stored in high RH with less water loss showed more accumulation of ABA and higher activity of abscisic acid aldehyde oxidase (AAO) compared to zucchini fruit stored in low RH with severe dehydration during long-term cold storage. Taken together, our results suggested that the high RH storage could reduce water loss and alleviate chilling injury in zucchini fruit after harvest by promoting the accumulation of ABA and proline.

Effects of cold storage duration and 1-MCP treatment on ripening and ‘eating window’ of ‘Hayward’ kiwifruit

BACKGROUND: It is known that 1-MCP delays softening in kiwifruit. Time to ripen (eating-window) and its variability are considered useful for planning commercial strategies. However, few studies report the firmness and quality changes during long-term cold storage. OBJECTIVES: To study the effects on ripening and sensory attributes of different 1-MCP treatments during long (180 d) and very long-term (≥210 d) cold storage. Then, the optimal 1-MCP dose was applied to determine the time to ripen after cold storage for 30 to 240 d. METHODS: Kiwifruits were treated with 1-MCP: 0.0 (control), 0.5 and 1.0μL L–1. Maturity indices and sensory analysis were achieved after 180 and 210 d of storage at 0 °C. Ethylene production was also measured. Firmness and number of fruits at eating-ripe state (at 20 °C) were monthly determined after 30 to 240 d of cold storage. RESULTS: 1-MCP (1.0μL L–1) delayed kiwifruit softening and prolonged the storage to up 180 d. Longer periods were associated to losses due to over-ripe. Eating windows of 1-MCP-treated fruits were longer than those for untreated fruits. CONCLUSIONS: 1.0μL L–1 1-MCP extends the postharvest life of ‘Hayward’ kiwifruit and prolongs the eating window, allowing to plan different commercialization strategies.

Emission of VOCs and quality evolution in response to repeated oxygen pull downs on ‘Conference’ pears during long-term cold storage

• Induced volatiles can be employed as ripening markers for dynamic storage. • Repeated low oxygen stress slows down the fruit ripening behavior. • No association was found between fluorescence peaks and fruit ethanol contents. • No fermentation in pears stored for 202 d below 0.5 kPa O 2 and 0.5 kPa CO 2 . The effect of long-term storage of ‘Conference’ pears under ultra-low oxygen levels with or without multiple oxygen pull downs of different duration on fruit quality, ethylene emission, fermentative metabolites and volatile organic compounds (VOCs) was investigated. Pears were cold stored for seven months under three different atmospheres: initial low oxygen stress (ILOS), dynamic low oxygen pull downs monitored with a chlorophyll fluorescence sensor (DLOS 1 ) and extended dynamic or repeated low oxygen pull downs (DLOS 2 ). Overall, the application of repeated oxygen pull downs in the atmosphere composition (DLOS 1 and DLOS 2 ) did not affect the fruit firmness upon removal from cold storage. Our results showed that fruit submitted to multiple oxygen pull downs (DLOS 1 and DLOS 2 ) ripened slower when further placed at 20 °C, as indicated by changes in the index of absorbance difference (I AD ), the fruit ethylene production capacity and the accumulation of ethanol within the fruit pulp. Moreover, the detected concentrations of specific VOCs (butyl acetate, hexyl propanoate and α-farnesene) inside the storage atmosphere correlated well with some ripening parameters (I AD ), thereby suggesting that specific VOCs could be used as fruit ripening state markers for real-time monitoring throughout the storage of ‘Conference’ pears.

Methyl jasmonate pretreatment improves aroma quality of cold-stored ‘Nanguo’ pears by promoting ester biosynthesis

Cold storage is widely used for delaying ripening and senescence; however, fruit aroma diminishes noticeably after long-term cold storage. The esters synthesized by the lipoxygenase (LOX) pathway are responsible for ‘Nanguo’ pear aroma. As methyl jasmonate (MeJA) is known to act on various fruit qualities, we investigated whether it acts via the LOX pathway in cold-stored ‘Nanguo’ pears. MeJA treatment increased the content of volatile esters and unsaturated fatty acids and the activities of alcohol acyltransferase, alcohol dehydrogenase, and LOX. It also up-regulated the expression of key genes (PuAAT, PuADH3, PuADH5, PuADH9, PuLOX1, and PuLOX3) in the LOX pathway and that of transcription factors (PuMYB21-like, PuMYB108-like, PuWRKY61, PuWRKY72, and PuWRKY31), whose genes were differentially expressed in preliminary transcriptome analysis. Therefore, considering its effects on LOX pathway-related genes and transcription factors, MeJA may be useful in preventing cold-storage-induced decline in ester biosynthesis, aroma, and consequently the quality of cold-stored ‘Nanguo’ pears.

Effect of gamma irradiation and subsequent cold storage on the development and predatory potential of seven spotted ladybird beetle Coccinella septempunctata Linnaeus (Coleoptera; Coccinellidae) larvae

Seven spot ladybird beetle, (Coccinella septempunctata) is a widely distributed natural enemy of soft-bodied insect pests especially aphids worldwide. Both the adult and larvae of this coccinellid beetle are voracious feeders and serve as a commercially available biological control agent around the globe. Different techniques are adopted to enhance the mass rearing and storage of this natural enemy by taking advantage of its natural ability to withstand under extremely low temperatures and entering diapause under unfavorable low temperature conditions. The key objective of this study was to develop a cost effective technique for enhancing the storage life and predatory potential of the larvae of C. septempunctata through cold storage in conjunction with the use of nuclear techniques, gamma radiations. Results showed that the host eating potential of larvae was enhanced as the cold storage duration was increased. Gamma irradiation further enhanced the feeding potential of larvae that were kept under cold storage. Different irradiation doses also affected the development time of C. septempuntata larvae significantly. Without cold storage, the lower radiation doses (10 and 25 GY) prolonged the developmental time as compared to un-irradiated larvae. Furthermore, the higher dose of radiation (50GY) increased the developmental time after removal from cold storage. This study first time paves the way to use radiation in conjunction with cold storage as an effective technique in implementation of different biological control approaches as a part of any IPM programs

Effects of Biostimulants on Annurca Fruit Quality and Potential Nutraceutical Compounds at Harvest and during Storage.

The cultivar Annurca is an apple that is cultivated in southern Italy that undergoes a typical redding treatment and it is appreciated for organoleptic characteristics, high pulp firmness, and nutritional profile. In this study, the effects of three different biostimulants (Micro-algae (MA), Protein hydrolysate (PEP), and Macro-algae mixed with zinc and potassium (LG)), with foliar application, on the quality parameters of Annurca apple fruits at the harvest, after redding, and at +60 and +120 days of cold storage were analyzed: total soluble solids (TSS) content, total acidity (TA), pH, firmness flesh, and red coloration of epicarp. Additionally, the polyphenolic quali-quantitative profile of pulp and peel was analyzed by UHPLC-Q-Orbitrap HRMS and Folin-Ciocalteu and the antioxidant capacity with the methods 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric-reducing antioxidant capacity (FRAP). The results obtained suggest that biostimulants are involved in the regulation of the secondary metabolism of the treated plants, acting positively on the quality of the Annurca fruits and their nutritional value. Fruits treated with PEP have shown, during cold storage, a significantly higher content of total polyphenols in flesh and a higher concentration of phloretin xylo-glucoside and phloridzin (350.53 and 43.58 mg/kg dw respectively). MA treatment caused, at the same time, an enhancement of flavonols between 0.6–28% and showed the highest total polyphenol content in the peel after 60 and 120 days of cold storage, with 2696.048 and 2570.457 mg/kg dw, respectively. The long-term cold storage (120 days) satisfactorily maintained phenolic content of fruits deriving from MA and PEP application, in accordance with data that were obtained for peel, showed an increase of 7.8 and 5.8%, respectively, when compared to the fruits cold stored for 60 days. This study represents the first detailed research on the use of different types of biostimulants on the quality of the Annurca apple from harvest to storage.

The Synergism of 1-Methylcyclopropene and Ethephon Preserves Quality of "Laiyang" Pears With Recovery of Aroma Formation After Long-Term Cold Storage.

A “Laiyang” pear is a climacteric fruit with a special taste and nutritional value but is prone to a post-harvest aroma compound loss and a loss in fruit quality. In this study, pears were pretreated with 0.5 μl L–1 1-methylcyclopropene (1-MCP) at 20°C for 12 h and then stored at 0 ± 1°C for 150 days to evaluate the influence of 1-MCP on fruit quality and the changes in components of volatile aromas. In addition, pears were further treated with 2 mmol L–1 ethephon. The effects of ethephon on the recovery of aroma production were investigated during the 150 day storage at 0 ± 1°C and the subsequent 7 day shelf life at 20 ± 1°C. Treatment with 1-MCP inhibited firmness loss, increased electrical conductivity, reduced respiration and ethylene production rates as well as the contents of soluble solids, and maintained the storage quality of the fruits. However, 1-MCP treatment inhibited the emission of volatile aromas in pear fruits by decreasing the activities of various enzymes, such as lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH), pyruvate carboxylase (PDC), and alcohol acetyltransferase (AAT). During the shelf-life, activities of the above mentioned enzymes were significantly enhanced, and a higher content of volatile aromas were found in fruits treated with 1-MCP + ethephon, while other qualities were not compromised. These results showed that 1-MCP treatment could effectively maintain the quality of the “Laiyang” pear during cold storage, and the additional application of ethephon on fruits during shelf-life may be a promising way to restore volatile aromas in pear fruits after long-term storage.

Identification of a New Variety of Avocados (Persea Americana Mill. CV. Bacon) with High Vitamin E and Impact of Cold Storage on Tocochromanols Composition.

(1) Background: Tocochromanols are a group of fat-soluble compounds including vitamin E (tocopherols and tocotrienols) and plastochromanol-8, and just one avocado can contain up to 20% of the required vitamin E daily intake. (2) Methods: HPLC and LC-MS/MS analyses were performed in avocados of various varieties and origin for the identification and quantification of tocopherols, tocotrienols and plastochromanol-8. After selection of the variety with the highest vitamin E content, we evaluated to what extent short- (4 h) and long-term (10 d) cold storage influences the accumulation of tocochromanols. (3) Results: Analyses revealed that “Bacon” avocados (Persea americana Mill. cv. Bacon) were the richest in vitamin E compared to other avocado varieties (including the highly commercialized Hass variety), and they not only accumulated tocopherols (with 110 µg of α-tocopherol per g dry matter), but also tocotrienols (mostly in the form of γ-tocotrienol, with 3 µg per g dry matter) and plastochromanol-8 (4.5 µg per g dry matter). While short-term cold shock did not negatively influence α-tocopherol contents, it increased those of γ-tocopherol, γ-tocotrienol, and plastochromanol-8 and decreased those of δ-tocotrienol. Furthermore, storage of Bacon avocados for 10 d led to a 20% decrease in the contents of α-tocopherol, whereas the contents of other tocopherols, tocotrienols and plastochromanol-8 were not affected. (4) Conclusions: It is concluded that Bacon avocados (i) are very rich in α-tocopherol, (ii) not only contain tocopherols, but also tocotrienols and plastochromanol-8, and (iii) their nutritional vitamin E value is negatively influenced by long-term cold storage.

Structure and Function of Porcine Arteries Are Preserved for up to 6 Days Using the HypoRP Cold-storage Solution.

Maintaining functional vessels during preservation of vascularized composite allografts (VCAs) remains a major challenge. The University of Wisconsin (UW) solution has demonstrated significant short-term benefits (4-6 h). Here we determined whether the new hypothermic resuscitation and preservation solution HypoRP improves both structure, survival, and function of pig arteries during storage for up to 6 days. Using porcine swine mesenteric arteries, the effects of up to 6-day incubation in a saline (PBS), UW, or HypoRP solution on the structure, cell viability, metabolism, and function were determined. After incubation at 4°C, for up to 6 days, the structures of the arteries were significantly disrupted, especially the tunica media, following incubation in PBS, in contrast with incubation in the HypoRP solution and to a lesser extent, in UW solution. Those disruptions were associated with increased active caspase 3 indicative of apoptosis. Additionally, while incubation in PBS led to a significant decrease in the metabolic activity, UW and HypoRP solutions allowed a stable to increased metabolic activity following 6 days of cold storage. Functional responsiveness to phenylephrine (PE) and sodium nitroprusside (SNP) decreased over time for artery rings stored in PBS and UW solution but not for those stored in HypoRP solution. Moreover, artery rings cold-stored in HypoRP solution were more sensitive to ATP. The HypoRP solution improved long-term cold storage of porcine arteries by limiting structural alterations, including the collagen matrix, reducing apoptosis, and maintaining artery contraction-relaxation functions for up to 6 days.

The effect of hot water, 1-MCP, and lovastatin on fresh-cut apples after long-term controlled atmosphere storage

This research was carried out over two years to determine the quality changes in fresh-cut apple slices processed after hot water, 1-methylcyclopropene 1-MCP , and lovastatin treatments followed by controlled atmosphere CA storage. Apples harvested at the optimum stage were immediately transferred to the postharvest laboratory by a refrigerated vehicle. Intact apples were exposed to three treatments: dipping into hot water 50 °C for 60 s , treating with lovastatin 1.25 mmol L-1 , and treating with 1-MCP 1 µL L-1 . Treated apples and the control group were stored in CA storage 2% O2 + 2% CO2 for 10 months. After long-term storage, the apples, sliced and packaged in plastic boxes, were stored at 0 °C and 90 ± 5% relative humidity RH for 14 days. Weight loss, soluble solid content, flesh firmness and color, titratable acidity, respiration rate, microbial count, and ethylene synthesis were determined during storage. As a result, a global beneficial effect of 1-MCP on sliced apples was observed, although its affirmative effect on ethylene synthesis and respiration rate vanished after 10 months of storage. 1-MCP-treated slices had better results in terms of microbial count, flesh firmness, external appearance, and weight loss compared to other applications. Lovastatin decreased the ethylene synthesis and respiration rate and was the best treatment to maintain the flavor of apple slices. Hot water and control treatments gave similar results for fruit quality and microbial activity. After long-term cold storage 10 months in CA, fresh-cut apple slices could be stored for 7 days with good quality at 0 °C and 90 ± 5% RH.

Effect of long-term cold storage on trehalose metabolism of pre-wintering Harmonia axyridis adults and changes in morphological diversity before and after wintering.

Harmonia axyridis is a major bio-control agent of pests in agriculture and forest ecosystems. It is also a globally important invasive insect species. To test whether dark elytra colour is associated with greater cold hardiness, we compared the survival rate of prolonged cold exposure in both yellow and black colour morphs of female and male H. axyridis. We determined the trehalose and glycogen content, trehalase activity, and the dynamics of genes associated with the trehalose metabolic pathway. Yellow forms predominated before winter began, however black forms increased from 11.15 to 30.46% after overwintering. There was no significant difference in trehalose content between the females and males during overwintering. Glycogen content in over-wintering yellow females and black males increased significantly, while it decreased in black females. Soluble trehalase activity increased significantly in all the insects except black females. Membrane-bound trehalase activity increased in black males, and decreased in black females. Trehalose and glycogen content and trehalase activity were regulated by differential expression of TRE and TPS genes. Female beetles weighed more than males and survived in low temperatures for longer periods of time, regardless of elytra colour, suggesting that mass is a stronger predictor of overwintering survival rather than colour morph. Our results provide a guide for comparing cold resistance in insects and a theoretical basis for cold storage of H. axyridis for use as natural enemies of pests in biological control programs.

Differences in the Amylase Inhibitor Gene SbAI Expression in Potato during Long-Term Tuber Cold Storage and in Response to Short-Term Cold Stress

Expression analysis of the amylase inhibitor gene SbAI in five potato cultivars (S. tuberosum) revealed SbAI downregulation in tubers during long-term (seven months) cold storage. Estimation of SbAI gene expression and starch content in leaves of S. tuberosum cv. Nadezhda and four wild potato species (Solanum sect. Petota) showed a dramatic increase in SbAI transcription accompanied by starch content drop in response to short-term cold stress.