Exploring the role of static magnetic field in supercooling storage from the viewpoint of meat quality and microbial community.

In order to explore the application prospects of static magnetic field (SMF) combined with supercooling in meat preservation, this study proposed a novel method of supercooling assisted by a stationary magnetic field (SMF + supercooling) for the preservation of chilled pork, evaluating its cooling rate and quality changes (e.g., water holding capacity, color, pH, and TVB-N), as well as the evolution trend of the microbiota. The results showed that SMF + supercooling significantly (P < 0.05) improved the cooling rate of pork. Compared to chilling and supercooling, SMF + supercooling significantly delayed the increase of TVB-N and TVC on the 12th day of storage (P < 0.05). SMF + supercooling treatment achieves the maintenance of pork water-holding capacity by inhibiting water migration, reducing drip loss, cooking loss, and centrifugal loss of pork. The 16S rDNA bacteria flora analysis demonstrated that SMF + supercooling treatment reduced the relative abundance of spoilage bacteria such as Acinetobacter, Streptococcus, and Pseudomonas, delaying the deterioration of pork quality caused by microbial growth. The SMF + supercooling treatment can be considered a novel refrigeration preservation method that delays the deterioration of pork quality and extends its shelf life.

Impact of sample refrigeration and freezing on the bacteriological counts of different bedding materials for dairy cows.

BACKGROUND: Different organic and inorganic bedding materials can be used in dairy farms. Among organic materials, there is an increasing interest in alternative substrates based on recycled manure solids (RMS). Microbiological analyses are crucial to monitor the microbial load and evaluate the presence of pathogens impacting animal welfare and health. However, logistic factors may hamper the possibility of immediately sending fresh samples to the laboratory, requiring storage in cooled conditions before analysis. METHODS: We assessed the impact of sample refrigeration and freezing of different organic and inorganic bedding substrates including separated raw manure solids (SRMS), anaerobically digested manure solids (ADMS), and new sand (NS), on the total bacterial count (TBC) and on different microbial classes. RESULTS: The TBC was higher in fresh NS and ADMS than in refrigerated and frozen samples of the same substrates; in addition, the TBC of ADMS was higher in refrigerated than frozen samples. The TBC of SRMS did not change significantly with refrigeration and freezing. Freezing reduced the total Gram-negative bacterial count more than refrigeration in all substrates. In fresh NS, Gram-negatives were higher than in both refrigerated and frozen NS. Escherichia coli counts were significantly lower in frozen than in refrigerated SRMS. However, both refrigeration and freezing of ADMS resulted in no E. coli growth. The coliform counts were also lower in frozen than refrigerated NS and SRMS. Frozen NS and ADMS showed lower counts compared to refrigeration for Gram-negative bacteria other than E. coli and coliforms. On the other hand, cold storage did not significantly impact the streptococci and streptococcus-like organisms (SSLO) count of all evaluated bedding substrates. CONCLUSION: Refrigeration and freezing affect the bacteriological results of bedding substrates, with freezing generally leading to lower counts than refrigeration. Whenever possible, preference should be given to analyzing fresh bedding samples, however, when necessary, refrigeration would be recommended over freezing, while acknowledging that the measured bacterial load might underestimate the actual microbial content.

Electric fields as effective strategies for enhancing quality attributes of meat in cold chain logistics: A review.

Meat quality (MQ) is unstable during cold chain logistics (CCL). Different technologies have been developed to enhance MQ during the CCL process, while most of them cannot cover all the links of the cold chain because of complex environment (especially transportation and distribution), compatibility issues, and their single effect. Electric fields (EFs) have been explored as a novel treatment for different food processing. The effects and potential advantages of EFs for biological cryopreservation have been reported in many publications and some commercial applications in CCL have been realized. However, there is still a lack of a systematic review on the effects of EFs on their quality attributes in meat and its applications in CCL. In this review, the potential mechanisms of EFs on meat physicochemical properties (heat and mass transfer and ice formation and melting) and MQ attributes during different CCL links (freezing, thawing, and refrigeration processes) were summarized. The current applications and limitations of EFs for cryopreserving meat were also discussed. Although high intensity EFs have some detrimental effects on the quality attributes in meat due to electroporation and electro-breakdown effect, EFs present good applicability opportunities in most CCL scenes that have been realized in some commercial applications. Future studies should focus on the biochemical reactions of meat to the different EFs parameters, and break the limitations on equipment, so as to make EFs techniques closer to usability in the production environment and realize cost-effective large-scale application of EFs on CCL.

Relationship between microorganisms and milk metabolites during quality changes in refrigerated raw milk: A metagenomic and metabolomic exploration.

Although cold storage at 4 °C can effectively prolong the shelf life of raw milk, it cannot prevent its eventual spoilage. In this study, we analyzed the main physicochemical and microbial indexes of raw milk stored at 4 °C for 6 days. The changes in microbial profiles and milk metabolites and their relationship during refrigeration were also explored. Metagenomic analysis performed using the Illumina Hiseq Xten sequencing platform revealed that the dominant genera in raw milk evolved from Acinetobacter, Streptococcus, Staphylococcus, and Anaplasma to Flavobacterium, Pseudomonas, and Lactococcus during cold storage. Using the UHPLC-Q-TOF MS method, 77 significantly different metabolites (p < 0.05) were identified, among which lipids were the most abundant (37). The most significant metabolic changes largely occurred at 3-4 days of refrigeration, coinciding with the rapid increase in dominant psychrotrophic bacteria. Subsequently, correlation analysis demonstrated that these lipid-related metabolites were significantly associated with Acinetobacter, Flavobacterium, and Pseudomonas. Both macro indicators and microanalysis indicated that the key stage of quality changes in raw milk was 3-4 days. Thus, this stage can be targeted for the quality control of raw milk.

The role of carcass processing (hot vs. cold boning) on pork belly morphological and mechanical characteristics.

This study assessed the effect of boning processing method (hot vs. cold) on pork belly morphological and mechanical traits and the evolution of these traits during refrigerated storage postmortem (PM). A total of 14 crossbred pigs were slaughtered and their carcasses and bellies processed under two conditions: hot boning (n = 14, right sides of carcasses cut immediately after slaughter) and cold boning (n = 14, left sides of carcasses cut 24 h PM). Morphological and mechanical evaluations were made at 1-, 5-, 24- and 48-h PM on the hot-boned bellies, and at 24 and 48 h on the cold-boned ones. Compared to the cold-boned bellies, the hot-boned ones were shorter, wider and thicker (P < 0.01), with greater firmness (flop distance and angle) (P < 0.001) and cohesiveness (skin-fat separation) (P < 0.05 in the dorsal and central sections). At 48 h PM, hot-boned bellies had a thicker skin (P < 0.001) and softer subcutaneous fat in the dorsal-cranial and central sections (finger scores and compression textural test) (P < 0.05). Morphological and mechanical traits for hot-boned bellies confirmed an intense shortening and hardening (increased firmness and cohesiveness), and a slight yield loss from 1 to 24 h PM. From 24 to 48 h PM, there was a certain flattening in hot-boned bellies that was associated with a slight softening (reduced firmness). Although a larger sample may be needed to corroborate these findings, they demonstrate the impact of carcass processing method and refrigerated storage time on belly quality. This may be useful for the pork industry for obtaining the desired type of belly.

Unraveling the spoilage characteristics of refrigerated pork using high-throughput sequencing coupled with UHPLC-MS/MS-based non-targeted metabolomics.

The spoilage of refrigerated pork involves nutrient depletion and the production of spoilage metabolites by spoilage bacteria, yet the microbe-metabolite interactions during this process remain unclear. This study employed 16S rRNA high-throughput sequencing and non-targeted metabolomics based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to reveal the core microbiota and metabolite profiles of pork during refrigeration. A total of 45 potential biomarkers were screened through random forest model analysis. Metabolic pathway analysis indicated that eleven pathways, including biogenic amine metabolism, pentose metabolism, purine metabolism, pyrimidine metabolism, phospholipid metabolism, and fatty acid degradation, were potential mechanisms of pork spoilage. Correlation analysis revealed nine metabolites-histamine, tyramine, tryptamine, D-gluconic acid, UDP-d-glucose, xanthine, glutamine, phosphatidylcholine, and hexadecanoic acid-as spoilage biomarkers, with Pseudomonas, Serratia, and Photobacterium playing significant roles. This study provides new insights into the changes in microbial and metabolic characteristics during the spoilage of refrigerated pork.

[Analysis of the operational conditions to preserve immunobiological products in vaccination rooms in Brazil: a mixed study]. / Análise das condições operacionais para conservação de imunobiológicos nas salas de vacinação do Brasil: estudo misto.

This study aimed to analyze the operational conditions to preserve immunobiological products in Brazil. This mixed-method study with a sequential explanatory design was developed in vaccination rooms in several Brazilian regions from 2021 to 2022. Its quantitative stage developed a descriptive cross-sectional study by applying the Immunobiological Conservation Assessment Scale to nursing professionals. Data were analyzed by descriptive statistics. Its qualitative stage developed a descriptive-exploratory study in cold chain instances with the respective technical managers and nursing professionals. The interviews were evaluated by thematic content analysis. The data were combined by connection, and joint-displays and meta-inferences were elaborated. Overall, 280 rooms were analyzed. Most were for exclusive use (79.6%), had polyurethane boxes (77.8%), and kept their equipment away from sunlight/heat (73.5%). Only 27.5% had batteries/generators and 26.5% had other temperature measuring instruments. In total, 60% had refrigerated rooms and 67.6%, air-conditioned rooms. This study found weaknesses associated with geographical conditions, infrastructure, material inputs, human and financial resources, work organization and management, turnover, and training. These findings showed the plurality of the Brazilian cold chain and identified the potentialities and weaknesses related to the structures and work processes in preserving immunobiological products, which require improvement.

Este estudo objetivou analisar as condições operacionais para conservação de imunobiológicos no Brasil. Trata-se de um estudo de método misto com delineamento explanatório sequencial, desenvolvido nas salas de vacinação de distintas regiões brasileiras entre 2021 e 2022. Na etapa quantitativa, desenvolveu-se um estudo transversal descritivo, com a aplicação da Escala de Avaliação da Conservação de Imunobiológicos aos profissionais de enfermagem. Os dados foram analisados por meio de estatística descritiva. Já na etapa qualitativa, desenvolveu-se um estudo descritivo-exploratório nas instâncias da cadeia de frio, com os respectivos responsáveis técnicos e profissionais de enfermagem. Analisou-se as entrevistas por meio da Análise de Conteúdo na Modalidade Temática. Os dados foram combinados mediante conexão, com elaboração de joint-displays e metainferências. Foram analisadas 280 salas, em que grande parte: era de uso exclusivo (79,6%); utilizava caixas de poliuretano (77,8%); e mantinha seus equipamentos distantes da incidência de luz solar/fontes de calor (73,5%). Apenas 27,5% dispunham de baterias/geradores e 26,5% de outros instrumentos de medição de temperatura. Sessenta por cento detinham câmaras refrigeradas e 67,6% ambientes climatizados. Revelaram-se fragilidades associadas a condições geográficas, infraestrutura, insumos materiais, recursos humanos e financeiros, organização e gestão do trabalho, rotatividade e capacitação. Os achados possibilitaram conhecer a pluralidade da cadeia de frio brasileira e permitiram a identificação de potencialidades e fragilidades na conservação de imunobiológicos relacionadas às estruturas e aos processos de trabalho que requerem aprimoramento.

Este estudio tuvo como objetivo analizar las condiciones operativas para la conservación de inmunobiológicos en Brasil. Estudio de método mixto con diseño explicativo secuencial, desarrollado en las salas de vacunación de las distintas regiones brasileñas, entre 2021 y 2022. En la etapa cuantitativa se desarrolló un estudio transversal descriptivo, con la aplicación de la Escala de Evaluación de la Conservación de Inmunobiológicos a los profesionales de enfermería. Los datos fueron analizados mediante estadística descriptiva. En la etapa cualitativa se desarrolló un estudio descriptivo-exploratorio en las instancias de la cadena de frío, con los respectivos responsables técnicos y profesionales de enfermería. Las entrevistas se analizaron por medio del Análisis de Contenido en la Modalidad Temática. Los datos fueron combinados mediante conexión, con elaboración de joint-displays y metainferencias. Se analizaron 280 salas. Gran parte era de uso exclusivo (79,6%); utilizaba cajas de poliuretano (77,8%) y mantenía sus equipos alejados de la incidencia de la luz solar/fuentes de calor (73,5%). Solo el 27,5% disponía de baterías/generadores y el 26,5% de otros instrumentos de medición de temperatura. El 60% tenía cámaras refrigeradas y el 67,6% ambientes climatizados. Se revelaron debilidades asociadas a las condiciones geográficas, la infraestructura, los insumos de materiales, los recursos humanos y financieros, la organización y gestión del trabajo, la rotación y la capacitación. Los hallazgos posibilitaron conocer la pluralidad de la cadena de frío brasileña y permitieron la identificación de potencialidades y debilidades de la conservación de inmunobiológicos relacionadas con las estructuras y los procesos de trabajo que requieren mejoras.

Hybrid Tabu-Grey wolf optimizer algorithm for enhancing fresh cold-chain logistics distribution.

The increasing public demand for fresh products has catalyzed the requirement for cold chain logistics distribution systems. However, challenges such as temperature control and delivery delays have led a significant product loss and increased costs. To improve the current situation, a novel approach to optimize cold chain logistics distribution for fresh products will be presented in the paper, utilizing a hybrid Tabu-Grey wolf optimizer (TGWO) algorithm. The proposed hybrid approach combines Tabu search (TS) and Grey wolf optimizer (GWO), employing TS for exploration and GWO for exploitation, aiming to minimize distribution costs in total and establish efficient vehicle scheduling schemes considering various constraints. The effectiveness of the TGWO algorithm is demonstrated through experiments and case studies compared to other heuristic algorithms. Comparative analysis against traditional optimization methods, including Particle swarm optimization (PSO), Whale optimization algorithm (WOA), and original GWO, highlights its superior efficiency and solution quality. This study contributes theories by demonstrating the efficacy of hybrid optimization techniques in complex supply chain networks and dynamic market environments. The practical implication lies in the implementation of TGWO to bolster distribution efficiency, cost reduction, and product quality maintenance throughout the logistics process, offering valuable insights for operational and strategic improvements by decision-makers. However, the study has limitations in generalizability and assumptions, suggesting future research areas including exploring new search operators, applying additional parameters, and using the algorithm in diverse real-life scenarios to improve its effectiveness and applicability.

Effect of konjac glucomannan-based preservation pads on quality changes in refrigerated large yellow croaker (Pseudosciaena crocea).

The purpose of this study was to evaluate the preservation effects of konjac glucomannan (KGM)/oregano essential oil (OEO) Pickering emulsion-based pads (K/OPE pads) on large yellow croaker (Pseudosciaena crocea) fillets stored at 4 °C. The K/OPE pads were fabricated using a freeze-drying technique. The homogeneous distribution of the OEO Pickering emulsions in the KGM matrix was observed using scanning electron microscopy. Fourier transform infrared spectroscopy confirmed that the OEO emulsions were encapsulated in the KGM and there was hydrogen bonding interaction between them. Compared with the KGM pads, the K/OPE pad groups demonstrated enhanced antioxidant and antimicrobial properties. When the content of OPE was increased from 20 % to 40 %, the antioxidant performance of the K/OPE pads increased from 48.09 % ± 0.03 % to 86.65 % ± 0.02 % and the inhibition range of Escherichia coli and Staphylococcus aureus increased to 13.84 ± 0.81 and 16.87 ± 1.53 mm, respectively. At the same time, K/OPE pads were more effective in inhibiting the formation of total volatile alkaline nitrogen and the production of thiobarbituric acid-reactive substances, thereby helping in reducing water loss and maintaining the muscle tissue structure of fish fillets for a longer storage time. Consequently, these K/OPE40 pads extended the shelf life of the fish fillets by an additional 4 days and delayed spoilage during refrigerated storage. The findings suggest that the K/OPE pads can effectively safeguard the quality of refrigerated large yellow croaker fillets, presenting their potential as an active packaging material in the fish preservation industry.

In-depth metaproteomics analysis reveals the protein profile and metabolism characteristics in pork during refrigerated storage.

Alterations in microbiotas and endogenous enzymes have been implicated in meat deterioration. However, the factors that mediate the interactions between meat quality and microbiome profile were inadequately investigated. In this study, we collected pork samples throughout the refrigeration period and employed metaproteomics to characterize both the pork and microbial proteins. Our findings demonstrated that pork proteins associated with the catabolic process are upregulated during storage compared to the initial stage. Pseudomonas, Clostridium, Goodfellowiella, and Gonapodya contribute to the spoilage process. Notably, we observed an elevated abundance of microbial proteins related to glycolytic enzymes in refrigerated pork, identifying numerous proteins linked to biogenic amine production, thus highlighting their essential role in microbial decay. Further, we reveal that many of these microbial proteins from Pseudomonas are ribosomal proteins, promoting enzyme synthesis by enhancing transcription and translation. This study provides intrinsic insights into the underlying mechanisms by which microorganisms contribute to meat spoilage.

Mechanical release of homogenous proteins from supramolecular gels.

A long-standing challenge is how to formulate proteins and vaccines to retain function during storage and transport and to remove the burdens of cold-chain management. Any solution must be practical to use, with the protein being released or applied using clinically relevant triggers. Advanced biologic therapies are distributed cold, using substantial energy, limiting equitable distribution in low-resource countries and placing responsibility on the user for correct storage and handling. Cold-chain management is the best solution at present for protein transport but requires substantial infrastructure and energy. For example, in research laboratories, a single freezer at -80 °C consumes as much energy per day as a small household1. Of biological (protein or cell) therapies and all vaccines, 75% require cold-chain management; the cost of cold-chain management in clinical trials has increased by about 20% since 2015, reflecting this complexity. Bespoke formulations and excipients are now required, with trehalose2, sucrose or polymers3 widely used, which stabilize proteins by replacing surface water molecules and thereby make denaturation thermodynamically less likely; this has enabled both freeze-dried proteins and frozen proteins. For example, the human papilloma virus vaccine requires aluminium salt adjuvants to function, but these render it unstable against freeze-thaw4, leading to a very complex and expensive supply chain. Other ideas involve ensilication5 and chemical modification of proteins6. In short, protein stabilization is a challenge with no universal solution7,8. Here we designed a stiff hydrogel that stabilizes proteins against thermal denaturation even at 50 °C, and that can, unlike present technologies, deliver pure, excipient-free protein by mechanically releasing it from a syringe. Macromolecules can be loaded at up to 10 wt% without affecting the mechanism of release. This unique stabilization and excipient-free release synergy offers a practical, scalable and versatile solution to enable the low-cost, cold-chain-free and equitable delivery of therapies worldwide.

Public health audit of vaccine cold chain management in general practice and community pharmacy in Western Australia.

OBJECTIVE: To support immunisation providers through a cold chain management audit. METHODS: An electronic audit survey using the National Vaccine Storage Guidelines as a gold standard was developed for general practice (GP) and community pharmacy. It included automated feedback, with individualised support from a clinical nurse specialist as required. Responses were analysed to determine the proportion of providers meeting criteria in four categories: procedures, refrigerators and equipment, temperature monitoring and emergency storage. RESULTS: Of 818 providers invited, 420 GPs (89.6%) and 276 pharmacies (82%) responded. Over 70% met all procedural and emergency storage criteria. Although most providers (98.1% GPs, 97.0% pharmacies) used a data logger, the proportion measuring at 5-minute intervals, reviewing data logger printouts weekly and manually recording minimum and maximum temperatures was lower. In total, 58% of providers required follow-up by the clinical nurse specialist, most regarding the need for equipment. CONCLUSION: An electronic audit enabled public health to engage with a large number of immunisation providers. Most reported high compliance with the national guidelines although opportunities for education were identified and actioned. IMPLICATIONS FOR PUBLIC HEALTH: Electronic solutions can support public health units to engage with providers to ensure vaccines remain effective and wastage is limited.

Which domestic refrigerator temperatures in Europe? - Focus on shelf-life studies regarding Listeria monocytogenes (Lm) in ready-to-eat (RTE) foods.

Listeria monocytogenes (Lm) is a pathogenic bacteria able to grow at refrigerated temperatures, widely distributed in the environment. This bacteria is susceptible to contaminate various food products of which refrigerated ready-to-eat foods (RTEF) may pose a risk for public health. In Europe, food business operators (FBOs) shall ensure that foodstuffs comply with the relevant microbiological criteria set out in the Regulation (EC) N°2073/2005. Food safety criteria for Lm are defined in RTEF throughout their shelf-life. FBOs should implement studies to demonstrate that the concentration of Lm does not exceed 100 CFU/g at the end of the shelf-life, taking into account foreseeable conditions of distributions, storage and use, including the use by consumers. However, this last part of the cold chain for food products is the most difficult to capture and control. For this purpose, the European Union Reference Laboratory for Lm (EURL Lm) launched an inquiry to its National Reference Laboratory network and reviewed the scientific literature from 2002 to 2020. The outcomes were integrated in the technical guidance document of the EURL Lm to assess shelf-life of RTEF which resulted in the recommendation to use 10 °C as the reference temperature to simulate the reasonably foreseen storage conditions in domestic refrigerators.

UV-ozone sterilization system: An intelligent solution for Northern shrimp (Pandalus borealis) cold chain transportation emergencies.

Sterilization of Northern shrimp (Pandalus borealis) is a key tool to ensure their freshness for post-production transportation. However, in the face of the specific problem of quality deterioration caused by the increase of storage environment temperature due to unexpected circumstances or the prolongation of temporary storage time, it is still a technical challenge to realize intelligent decision-making and higher sterilization efficiency. In this paper, we propose an intelligent UV-Ozone sterilization system suitable for cold chain transportation of Northern shrimp (Pandalus borealis). Using hierarchical analysis, equipartition method and the prediction method of generalized linear model, combined with the technology of intelligent control and remote control, we realized the automatic control of the system's UV irradiance from 324 âˆ¼ 1620 J/m2, and ozone concentration from21.4 ∼ 107 mg/cm3 in a graded manner. The accuracy of the predicted structure was verified using a combination of direct measurement and simulation. In addition, the key model of the system, the intensity level decision model, was tested, and the test results showed that the decision model was able to accurately make decisions during the sterilization of Northern shrimp (Pandalus borealis), and the system was able to achieve a sterilization effect of 1-3 orders of magnitude. This reduces quality loss due to unexpected conditions, facilitates real-time monitoring of transported samples by staff, extends the shelf life of the samples, and improves the accuracy of sterilization, increasing the economic value of Northern shrimp (Pandalus borealis).

Analysis of Internet of things implementation barriers in the cold supply chain: An integrated ISM-MICMAC and DEMATEL approach.

Integrating Internet of Things (IoT) technology inside the cold supply chain can enhance transparency, efficiency, and quality, optimize operating procedures, and increase productivity. The integration of the IoT in this complicated setting is hindered by specific barriers that require thorough examination. Prominent barriers to IoT implementation in a cold supply chain, which is the main objective, are identified using a two-stage model. After reviewing the available literature on IoT implementation, 13 barriers were identified. The survey data were cross-validated for quality, and Cronbach's alpha test was employed to ensure validity. This study applies the interpretative structural modeling technique in the first phase to identify the main barriers. Among these barriers, "regulatory compliance" and "cold chain networks" are the key drivers of IoT adoption strategies. MICMAC's driving and dependence power element categorization helps evaluate barrier interactions. In the second phase of this study, a decision-making trial and evaluation laboratory methodology was employed to identify causal relationships between barriers and evaluate them according to their relative importance. Each cause is a potential drive, and if its efficiency can be enhanced, the system benefits as a whole. The findings provide industry stakeholders, governments, and organizations with significant drivers of IoT adoption to overcome these barriers and optimize the utilization of IoT technology to improve the effectiveness and reliability of the cold supply chain.

Influence of short-term refrigeration on collagen-dependent signalling mechanisms in stored platelets.

Platelet concentrates (PC) are used to treat patients with thrombocytopenia and hemorrhage, but there is still the demand to find the optimal strategy for temperature-dependent storage of PC. Recently, we could show that cold storage for 1 h (short-term refrigeration) is sufficient to induce enhanced platelet responsiveness. The aim of this study was to investigate effects of cold storage on collagen-dependent activating signalling pathways in platelets from apheresis-derived PC (APC). APC on day 1 or day 2 of storage, were either continuously kept at room temperature (RT, 22 °C), or for comparison, additionally kept at cold temperature (CT, 4 °C) for 1 h. CD62P expression was determined by flow cytometry. Western Blot technique was used to analyze collagen-induced phosphorylation of p38, ERK1/2 or Akt/PKB and its inhibition by prostaglandin E1 (PGE1) or nitric monoxide donor. Adhesion of platelets on collagen-coated surfaces and intracellular phosphorylation of vasodilator-stimulated phosphoprotein (VASP) was visualized by immune fluorescence microscopy. CD62P expression was increased after short-term refrigeration. CT exposition for 1 h induced an elevation of basal ERK1/2 phosphorylation and an alleviation of PGE1- or DEA/NO-suppressed ERK1/2 phosphorylation in APC on day 1 and 2 of storage. Similar, but more moderate effects were observable for p38 phosphorylation. Akt/PKB phosphorylation was increased only in APC on day 2. Refrigeration for 1 h promoted platelet adhesion and reduced basal VASP phosphorylation in adherent platelets. The attenuation of inhibitory signalling in short-term refrigerated stored platelets is associated with enhanced reactivity of activating signalling pathways, especially ERK1/2. Functionally, these processes correlate with increased adhesion of refrigerated platelets on collagen-coated surfaces. The results help to further optimize temperature-dependent strategies for platelet storage.

Exploring the effect of part differences on metabolite molecule changes in refrigerated pork: Identifying key metabolite compounds and their conversion pathways.

Effect of part differences on metabolite molecule alterations in refrigerated pork was investigated. A metabolomics methodology combined with chemometric analysis was successfully established to identify key compounds and their conversion pathways, including precursors and volatile metabolites, in the Longissimus lumborum as well as the breast and flank stored for 11 days. In total, 12 discriminative precursors were identified using the Short Time-series Expression Miner. In tandem with Random Forest and ANOVA analyses, nine volatile metabolites were identified as key compounds that could be attributed to differences in pork sections. Bidirectional orthogonal partial least squares analysis revealed a potential correlation between these key metabolites and discriminative precursors. Metabolic pathway enrichment analysis demonstrated that the primary metabolic process affected by variations in pork sections is linoleic acid metabolism, which participates in the metabolism of cysteine and glutamic acid to produce methoxy-phenyl-oxime. This study provides valuable insights into the identification of differential metabolites.

Carvacrol-loaded nanoemulsions stabilized by soy protein isolate / chitooligosaccharide conjugates inhibited the oxidation and conformational variations of myofibrillar proteins in refrigerated sea bass (Lateolabrax maculatus).

Soy isolate protein / chitooligosaccharide (SPI/COS) glycosylated conjugates was prepared and employed as an emulsifier to stabilize carvacrol-loaded nanoemulsions (CNE-SPI/COS). The effects of CNE-SPI/COS on the oxidation and aggregation of myofibrillar protein (MPs) from sea bass (Lateolabrax maculatus) were investigated. Samples were immersed in sterile water (CK), SPI/COS solution and CNE-SPI/COS solution, respectively, follow by a 15-day refrigerated storage. MPs were extracted from fish fillets at 3-day intervals, then assessed for the oxidation degree and conformational changes in MPs, as well as structural variations in myofibrils. Compared with the CK group, the results obtained from protein oxidation assessment clarified that the oxidation and aggregation of MPs was significantly reduced by the CNE-SPI/COS treatment, as evidenced by the higher total sulfhydryl content and Ca2+-ATPase activity and lower surface hydrophobicity. Conformational analysis of MPs showed that CNE-SPI/COS was effective in maintaining the ordered secondary structure of MPs and reducing the exposure of hydrophobic residues in the hydrophobic core of the tertiary structure. In addition, CNE-SPI/COS was found to be effective in protecting the microstructure of muscle fibers and myofibrils in fish fillets. These results suggest that CNE-SPI/COS can be a promising method to prevent protein oxidation and aggregation in fish.

Revealing the spoilage characteristics of refrigerated prepared beef steak by advanced bioinformatics tools.

BACKGROUND: Although microorganisms are the main cause of spoilage in prepared beef steaks, very few deep spoilage mechanisms have been reported so far. Aiming to unravel the mechanisms during 12 days of storage at 4 °C affecting the quality of prepared beef steak, the present study investigated the changes in microbial dynamic community using a combined high-throughput sequencing combined and bioinformatics. In addition, gas chromatography-mass spectrometry combined with multivariate statistical analysis was utilized to identify marker candidates for prepared steaks. Furthermore, cloud platform analysis was applied to determine prepared beef steak spoilage, including the relationship between microbiological and physicochemical indicators and volatile compounds. RESULTS: The results showed that the dominant groups of Pseudomonas, Brochothrix thermosphacta, Lactobacillus and Lactococcus caused the spoilage of prepared beef steak, which are strongly associated with significant changes in physicochemical properties and volatile organic compounds (furan-2-pentyl-, pentanal, 1-octanol, 1-nonanol and dimethyl sulfide). Metabolic pathways were proposed, among which lipid metabolism and amino acid metabolism were most abundant. CONCLUSION: The present study is helpful with respect to further understanding the relationship between spoilage microorganisms and the quality of prepared beef steak, and provides a reference for investigating the spoilage mechanism of dominant spoilage bacteria and how to extend the shelf life of meat products. © 2024 Society of Chemical Industry.