Self-oscillating polymeric refrigerator with high energy efficiency.

Electrocaloric1,2 and electrostrictive3,4 effects concurrently exist in dielectric materials. Combining these two effects could achieve the lightweight, compact localized thermal management that is promised by electrocaloric refrigeration5. Despite a handful of numerical models and schematic presentations6,7, current electrocaloric refrigerators still rely on external accessories to drive the working bodies8-10 and hence result in a low device-level cooling power density and coefficient of performance (COP). Here we report an electrocaloric thin-film device that uses the electro-thermomechanical synergy provided by polymeric ferroelectrics. Under one-time a.c. electric stimulation, the device is thermally and mechanically cycled by the working body itself, resulting in an external-driver-free, self-cycling, soft refrigerator. The prototype offers a directly measured cooling power density of 6.5 W g-1 and a peak COP exceeding 58 under a zero temperature span. Being merely a 30-µm-thick polymer film, the device achieved a COP close to 24 under a 4 K temperature span in an open ambient environment (32% thermodynamic efficiency). Compared with passive cooling, the thin-film refrigerator could immediately induce an additional 17.5 K temperature drop against an electronic chip. The soft, polymeric refrigerator can sense, actuate and pump heat to provide automatic localized thermal management.

Application of gelatin-based zinc oxide nanoparticles bionanocomposite coatings to control Listeria monocytogenes in Talaga cheese and camel meat during refrigerated storage.

Listeria monocytogenes is a concerning foodborne pathogen incriminated in soft cheese and meat-related outbreaks, highlighting the significance of applying alternative techniques to control its growth in food. In the current study, eco-friendly zinc oxide nanoparticles (ZnO-NPs) were synthesized using Rosmarinus officinalis, Punica granatum, and Origanum marjoram extracts individually. The antimicrobial efficacy of the prepared ZnO-NPs against L. monocytogenes was assessed using the agar well diffusion technique. Data indicated that ZnO-NPs prepared using Origanum marjoram were the most effective; therefore, they were used for the preparation of gelatin-based bionanocomposite coatings. Furthermore, the antimicrobial efficacy of the prepared gelatin-based bionanocomposite coatings containing eco-friendly ZnO-NPs was evaluated against L. monocytogenes in Talaga cheese (an Egyptian soft cheese) and camel meat during refrigerated storage at 4 ± 1 oC. Talaga cheese and camel meat were inoculated with L. monocytogenes, then coated with gelatin (G), gelatin with ZnO-NPs 1% (G/ZnO-NPs 1%), and gelatin with ZnO-NPs 2% (G/ZnO-NPs 2%). Microbiological examination showed that the G/ZnO-NPs 2% coating reduced L. monocytogenes count in the coated Talaga cheese and camel meat by 2.76 ± 0.19 and 2.36 ± 0.51 log CFU/g, respectively, by the end of the storage period. Moreover, G/ZnO-NPs coatings controlled pH changes, reduced water losses, and improved the sensory characteristics of Talaga cheese and camel meat, thereby extending their shelf life. The obtained results from this study indicate that the application of gelatin/ZnO-NPs 2% bionanocomposite coating could be used in the food industry to control L. monocytogenes growth, improve quality, and extend the shelf life of Talaga cheese and camel meat.

One-week storage of refrigerated bovine milk does not affect the size, concentration, or molecular properties of extracellular vesicles.

Milk extracellular vesicles (EV) have gained extensive attention as promising diagnostic and therapeutic tools. Pre-analytical raw milk storage at low temperatures is an ordinary and usually necessary step after sample collection. It is known that direct freezing of unprocessed whole milk contaminates the native pool of milk EV with other cell structures. However, less evidence is available regarding prolonged cooling at 4°C. The current study assessed whether pre-analytical storage of bovine raw milk for several days affected EV isolation and further analysis. To confirm the independence from the health status of the mammary gland, we analyzed milk samples stored at 4°C for 1, 2, 3, and 7 d past collection, respectively, from 2 quarters of the same cow with different somatic cell counts (SCC). Seven days of refrigeration did not change the milk EV size, concentration, or morphology. We did not detect any changes in the EV cargo regarding the amount of protein and RNA, nor in the specific EV markers TSG101, CD9, and CD81 in milk from quarters with high and low SCC. Overall, we observed fewer CD81 and CD9 markers in quarters with high SCC. Moreover, we found no reduction in the mastitis-related miRNA bta-miR-223-3p, suggesting that refrigeration for several days up to 1 wk is a possible storage option compatible with further EV analyses. The findings of this study enhance the confidence that milk EV are highly stable in the raw milk matrix.

Relationships of quality indices with wooden breast myopathy severity in chicken breast meat under refrigerated storage.

1. This study investigated the relationships of quality indices with the severity of wooden breast (WB) myopathy in chicken breast meat under refrigerated storage. The physicochemical properties, water-holding capacity (WHC), microbial quality and fatty acid profiles of normal chicken breast meat samples (NOR samples, n = 63), moderate WB (MWB, n = 63) myopathy and severe WB (SWB, n = 63) myopathy (MWB and SWB samples, respectively) were evaluated immediately after sampling and after 4 and 8 d of refrigerated storage at 4°C.2. Total collagen, fat, saturated and monounsaturated fatty acid contents, redness and pH of the SWB and MWB samples were higher than the NOR samples. The SWB samples that were stored for 8 d had poor WHC, total viable counts (TVC) of higher than 7.0log colony-forming units, total volatile basic nitrogen (TVB-N) content of greater than 15 mg/100 g and a thiobarbituric acid - reactive substance level of higher than 1 mg/kg malondialdehyde.3. No significant difference was observed in the TVB-N content and TVC of the MWB and NOR samples during storage. Polyunsaturated fatty acid content was lower in the SWB and MWB samples than in the NOR samples. The SWB samples were tougher than the MWB and NOR samples after 8 d of refrigeration.4. In conclusion, the quality of chicken breast meat with SWB myopathy degraded considerably over time; thus, such meat should not be subjected to extended refrigeration for storage.

Mediating Role of Viral Anxiety and Insomnia in Relationship Between Work-Related Stress and Depression Among Cold Chain Workers During COVID-19 Pandemic.

BACKGROUND: Here we investigated whether cold chain workers' insomnia, work-related stress, and viral anxiety contributed to their depression. Furthermore, we investigated the role of viral anxiety in mediating the association between work-related stress and depressive symptoms. METHODS: All 200 invited cold chain workers voluntarily responded to an online survey. All were working at a market in Taiyuan, Shanxi Province, China, and responsible for testing nucleic acids in imported cold chain foods and disinfecting outer packaging at government request. We collected their demographic variables and rated their symptoms using the Stress and Anxiety to Viral Epidemics-6 Items (SAVE-6), Patient Health Questionnaire-9, Insomnia Severity Index (ISI), Perceived Stress Scale (PSS), and Maslach Burnout Inventory - General Survey (MBI-GS). RESULTS: Cold chain workers' depression was significantly correlated with higher SAVE-6 (r = 0.450, P < 0.01), ISI (r = 0.603, P < 0.01), MBI-GS (r = 0.481, P < 0.01), and PSS (r = 0.390, P < 0.01) scores. SAVE-6 score was significantly correlated with ISI (r = 0.462, P < 0.01), MBI-GS (r = 0.305, P < 0.01), and PSS (r = 0.268, P < 0.01) scores. Linear regression revealed that their depression was predicted by SAVE-6 (ß = 0.183, P = 0.003), ISI (ß = 0.409, P < 0.001), and MBI-GS (ß = 0.236, P = 0.002, adjusted R² = 0.440, F = 40.04, P < 0.001) scores. Mediation analysis showed that their burnout directly influenced their depression, while viral anxiety or insomnia severity mediated the influence of burnout on depression. CONCLUSION: The study showed that burnout was a direct cause of depression and that viral anxiety and insomnia severity mediated the relationship between burnout and depression.

Biological behavior of Chrysomya putoria (Wiedemann, 1819) (Diptera: Calliphoridae) after refrigeration: Logistics for use in Biotherapy.

The influence of refrigeration on the post-embryonic development of Chrysomya putoria larvae was evaluated, regarding its resistance in the logistics of storage and distribution in biotherapy. Previously sterilized larvae were submitted to four periods of storage under refrigeration (T1=12 h, T2=24 h, T3=48 h and T4=72 h) and control (without sterilization and refrigeration). Newly hatched larvae (0.200 g) were stored between 3 and 9ºC. After refrigeration, 40 neo-larvae (in triplicate) were transferred to 50 g of protein diet and incubated in an acclimatized chamber. There was a significant difference in the larval body mass (T1 and T2) and in the duration of larval, pupal and total development (T3 and T4). The sex ratios found in the four treatments did not differ from what was expected. Normality rates were 100% for all treatments. There was no significant difference between the Control, T1 and T2 treatments for larval, pupal and total viability. There was a significant difference between control (C) and T4 (larval viability), between C, T3 and T4 (pupa) and between C and T4 (total). C. putoria has resistance under refrigeration and storage of up to 56 h, presenting viability above 70% for use in biotherapy.

Effects of time and temperature of storage on chemical and nutritional characteristics of raw milk for Provolone Valpadana PDO cheesemaking: a multivariate approach.

We evaluated the possibility of increasing the storage temperature of raw milk for Provolone Valpadana cheesemaking, to identify the most suitable conditions of time and temperature for a pre-maturation process. We used Principal Component Analysis (PCA) to analyze the overall effects of different storage conditions on chemical, nutritional and technological characteristics of the raw milk. Four different thermal storage cycles, two at fixed temperature/time (6 and 12°C for 60 h) and two with two-phase thermal cycle (10 and 12°C for 15 h, followed by refrigeration at 4°C for 45 h) were studied. Although a moderate heterogeneity among raw milks from the 11 producers of Provolone Valpadana cheese was observed, PCA revealed the critical aspects of the extreme storage conditions (60 h of refrigeration). Some samples resulted in anomalous behaviors, probably related to unexpected fermentation phenomena occurring with increasing storage temperature. The acidification and the increase in the contents of lactic acid, soluble calcium, and degree of retinol isomerization observed in the anomalous samples can compromise the technological functionality of milk. Conversely, the storage with a two-phase thermal cycle did not lead to variations in any measured characteristic, suggesting that mild refrigeration conditions (10 or 12°C for 15 h followed by 4°C for 45 h) could be a good compromise in favoring milk pre-maturation without altering its quality characteristics.

[Clinical Practice Guidelines for Vaccine Management in Ambulatory Care: a Systematic Review Following the AGREE II Approach]. / Impfstoffmanagement in der ambulanten Versorgung: ein systematischer Review internationaler Empfehlungen und Implikationen für das deutsche Gesundheitswesen.

BACKGROUND: Breaches in the cooling chain with exposure of vaccines to temperatures outside the target range of +2°C to +8°C may reduce their efficacy and impair immune responses. Following the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach, this review assesses the quality and content of international clinical practice guidelines on vaccine management. The results were used to derive recommendations for the vaccine management in ambulatory care in Germany. METHODS: Based on a systematic search and screening process with predefined criteria, the selected guidelines were rated by three reviewers using the AGREE II domains: scope and purpose, stake-holder involvement, rigor of development, clarity of presentation, applicability, and editorial independence. The content of the guidelines was retrieved and summarized according to five predefined categories: cold chain, responsibilities, equipment, storage, and monitoring. The review was registered in PROSPERO (CRD42021270524). RESULTS: A total of nine clinical practice guidelines were selected for evaluation. The sum score of the documents varied between 17% to 89% of the maximum possible score. All guidelines included recommendations in the five content categories but differed in detail. The key recommendations were: a) continuous cold chain required; b)≥2 trained, responsible staff members; c) storage in original wrappings; d) appropriate, preferably purpose-built refrigerator with two-point thermometer or data logger; e) routinely implemented monitoring processes including daily temperature recording. A public monitoring system was recommended in some guidelines. CONCLUSION: Our systematic review identified key information for vaccine storage and management to support the future development of German recommendations for vaccine storage.

Investigation of Thermodynamic Properties of Dimethyl Phosphate-Based ILs for Use as Working Fluids in Absorption Refrigeration Technology.

In the current research, the binary solution containing ionic liquid (IL), 1-ethyl-1-methylmorpholinium dimethyl phosphate ([C1C2MOR][DMP]), 1-ethyl-1-methylpiperidinium dimethyl phosphate ([C1C2PIP][DMP]), or N,N,N-triethyl-N-methylammonium dimethyl phosphate ([N1,2,2,2][DMP]) with ethanol are investigated as new working fluids for absorption refrigeration technology. The IL was mixed with ethanol, which was considered as a refrigerant. Experimental (vapor + liquid) phase equilibria (VLE) of these binary systems were measured by an ebulliometric method within a temperature range from T = (328.15 to 348.15) K with an increment of 10 K and pressures up to 90 kPa. Experimental VLE data were correlated using non-random two-liquid (NRTL) within the maximum average relative deviation of 0.45%, which confirms the effectiveness of using such a model for calculations. Each of the proposed binary systems exhibit a negative deviation from Raoult's law, which is a very important characteristic for working pairs used in absorption heat pumps or absorption refrigerators. From a technological point of view, measurements of physicochemical properties play an important role. In this research, liquid density and dynamic viscosity were determined at temperatures from T = (293.15 to 338.15) K at ambient pressure over the whole concentration range. These properties were correlated using empirical equations. From experimental density data, the excess molar volumes were determined and correlated using the Redlich-Kister type equation. Ionic liquid: [C1C2MOR][DMP] and [C1C2PIP][DMP] were synthesized and characterized using NMR analysis. The thermophysical characterization of pure ILs, including glass transition temperature (Tg) and heat capacity at the glass transition temperature (ΔgCp), was determined using the differential scanning calorimetry technique (DSC) at atmospheric pressure. In this work, the combination of basic studies on the effect of the cation structure of an ionic liquid on the properties of their solutions with ethanol and the possibility of future application of the tested systems in a viable refrigeration system are presented.

To culture or not to culture: careful assessment of metabarcoding data is necessary when evaluating the microbiota of a modified-atmosphere-packaged vegetarian meat alternative throughout its shelf-life period.

BACKGROUND: As the increased consumption of ready-to-eat meat alternatives is a fairly recent trend, little is known about the composition and dynamics of the microbiota present on such products. Such information is nonetheless valuable in view of spoilage and food safety prevention. Even though refrigeration and modified-atmosphere-packaging (MAP) can extend the shelf-life period, microbial spoilage can still occur in these products. In the present study, the microbiota of a vegetarian alternative to poultry-based charcuterie was investigated during storage, contrasting the use of a culture-dependent method to a culture-independent metagenetic method. RESULTS: The former revealed that lactic acid bacteria (LAB) were the most abundant microbial group, specifically at the end of the shelf-life period, whereby Latilactobacillus sakei was the most abundant species. Metabarcoding analysis, in contrast, revealed that DNA of Xanthomonas was most prominently present, which likely was an artifact due to the presence of xanthan gum as an ingredient, followed by Streptococcus and Weissella. CONCLUSIONS: Taken together, these results indicated that Lb. sakei was likely the most prominent specific spoilage organisms (SSO) and, additionally, that the use of metagenetic analysis needs to be interpreted with care in this specific type of product. In order to improve the performance of metagenetics in food samples with a high DNA matrix but a low bacterial DNA load, selective depletion techniques for matrix DNA could be explored.

Active Refrigerators Powered by Inertia.

We present the operational principle for a refrigerator that uses inertial effects in active Brownian particles to locally reduce their (kinetic) temperature by 2 orders of magnitude below the environmental temperature. This principle exploits the peculiar but so-far unknown shape of the phase diagram of inertial active Brownian particles to initiate motility-induced phase separation in the targeted cooling regime only. Remarkably, active refrigerators operate without requiring isolating walls opening the route toward using them to systematically absorb and trap, e.g., toxic substances from the environment.

Hyperbaric treatment of platelets extends in vitro storage to 14 days.

BACKGROUND: Platelets for transfusion have a storage time of 5-7 days at 22°C-24°C, which results in a strain on the supply chain and supply shortages. We describe a novel method to extend platelet storage using xenon (Xe) gas under high pressure and refrigeration. STUDY DESIGN AND METHODS: Apheresis platelets (APU) prepared in 65% platelet additive solution (PAS) were stored under standard conditions (SC) at 20°C-24°C to Day 5. Paired APUs were prepared with Xe and stored to Day 14 at 2°C-6°C under hyperbaric conditions (XHC). A standard panel of in vitro assays was conducted. RESULTS: XHC platelets were viable out to Day 14. The average pH of Day 14 platelets was 6.58, and 86% maintained some degree of swirl compared with 7.02 and 100% swirl for Day 5 SC platelets. The rate of glycolysis was reduced under XHC storage with less glucose consumption and lactate generation. Activation levels for Day 14 platelets, while increased, did not prevent response to agonists in vitro, including epinephrine + Adenosine 5-Diphosphate (EPI/ADP) and thrombin receptor-activating peptide (TRAP) aggregation. Thromboelastogram (TEG) assessment showed 80% or greater conservation of platelet function for Day 14 xenon stored platelets compared with Day 5 SC platelets. DISCUSSION: Platelet storage with the Xe/hyperbaric/cold method is a feasible candidate for extension of storage to 14 days based on in vitro characteristics. In vivo recovery and survival studies are indicated. The capability to extend platelet storage to 14 days would make large strides toward resolving issues of platelet outdating for prophylactic use.

Antivenoms, hepatitis B vaccine and oral polio vaccine can be considered for storage and handling outside the cold chain following the innovative 'controlled temperature chain' approach.

Possible applicability of controlled temperature chain (CTC) for selected antisera and vaccines was evaluated. Bivalent oral polio vaccine (OPV), hepatitis B vaccine (HepB vaccine; monovalent and combined) and antisera (lyophilized and liquid scorpion-antivenom and liquid snake-antivenom) were tested. Samples were stored at accelerated (35 ± 5 °C) and freezing (-25 ± 5 °C) conditions for 24 h, one week and one month in addition to recommended storage condition (2-8 °C), except OPV samples that were tested at accelerated and refrigerated (2-8 °C) conditions compared to recommended storage conditions (-25 ± 5 °C). All samples were tested for potency. Protein content and composition were determined for antisera samples. All vaccine vial-monitors were evaluated. HepB vaccine was subjected to aluminum-content assay, shake test and microscopical examination. No significant change in antisera potency was detectable under accelerated condition for a week. OPV stored in refrigerator for a month and at accelerated condition for 48 h maintained acceptable potency. Monovalent and combined HepB vaccine maintained acceptable potency under accelerated condition for a month and a week, respectively. Freezing adversely affected HepB vaccine. In conclusion, reevaluation of storage conditions of tested products is urgently required; this can reduce storage costs and improves their availability. Other products should be tested for possible CTC applicability.

Alternate Approach in Storing and Shipment of SARS-CoV-2 RNA Samples with the Use of FTA Cards.

Shipment of COVID-19 specimens within the country or overseas at long distances requires cold chain facility using dry ice and triple packing to prevent the risk of COVID-19 infection to the personnel involved in sample transport. The present study aimed to utilize FTA card technology as an alternate means of sample transport and storage across the country. Twenty-one SARS-CoV-2 lab confirmed samples with different Ct value (High, medium & low) were used to detect viral load in samples loaded on FTA card and further compared with VTM samples. The SARS-CoV-2 RNA was detected by rRT-PCR after storing for 14 days at 4 °C and 37 °C. The present study evaluated the utility of FTA cards for preserving the SARS CoV-2 RNA for 14-day period. A significant difference (P < 0.05) was observed in the cycle threshold (ΔCt 4-5) values obtained from FTA and VTM viral samples but it did not affect the positivity. The SARS-CoV-2 RNA could be recovered efficiently from FTA sample stored at 4 °C and 37 °C for 14 days. Thus, FTA cards could be an alternate option for transporting the samples at ambient temperature for a long time.

Low-pressure long-time or moderate pressure pasteurization at room temperature by hyperbaric inactivation as a new nonthermal preservation approach - A case study on milk.

A new nonthermal food pasteurization approach is here presented for the first time, proposed to be called low-pressure long-time (LPLT) pasteurization or moderate pressure pasteurization (MPP) by hyperbaric inactivation (HI). To test this novel pasteurization process on raw milk, MPP by HI was carried out at three different pressure levels (150, 200 and 250 MPa), over 24 h, at naturally variable uncontrolled room temperature (≈20 °C) and compared with high pressure processing (HPP) at 600 MPa (one cycle for 90 s and a second cycle of 120 s) followed by storage under refrigeration for 21 days. Based on the results obtained, MPP at 250 MPa over 24 h caused higher microbial inactivation on total aerobic mesophiles (TAM), lactic acid bacteria (LAB) and Enterobacteriaceae (ENT) (of at least 2.2, 1.7 and 1.3 log CFU/mL, respectively) than HPP (1.1, 1.0 and 1.2 log CFU/mL, for the same microorganisms). Moreover, MPP showed a clear reduction of inoculated microorganisms to below the detection limit, in only 16 h for all pressures with reductions of at least 5.7, 5.4 and 5.5 for Listeria innocua, Salmonella senftenberg, and Escherichia coli, respectively. Additionally, during preservation under refrigeration, MPP samples (200 MPa and 250 MPa), maintained lower TAM/LAB/ENT compared to HPP, being the counts below the quantification/detection limit for at least 21 days for MPP by HI. MPP (200 MPa and 250 MPa) resulted also in counts below the detection limit for the inoculated microorganisms up to at least 21 days under refrigeration. The results of MPP by HI are very promising as a new nonthermal food pasteurization, since over 5 log reduction of vegetative bacteria were achieved, with counts maintained below the quantification/detection limit for at least 21 days under refrigeration.

Live holding of red king crab (Paralithodes camtschaticus) and snow crab (Chionoecetes opilio) - Effect on microbial growth in processed leg meat during refrigerated storage.

The red king crab (RKC, Paralithodes camtschaticus) and snow crab (SC, Chionoecetes opilio) are valuable decapods that can undergo live holding (LH) in onshore facilities before either live export or processing into two cooked-frozen sections (i.e., clusters). This study investigated the effect of the LH time (up to two months without feeding) and temperature (5│10 °C for RKC; 1│5 °C for SC) on the total viable psychrotrophic count (TVCP) and Pseudomonas spp. in the leg meat of cooked RKC and SC. The effect of freezing after cooking was also evaluated. The counts were determined during storage at 4 °C after cooking on the clusters undergoing either immediate refrigeration (IR) or 24-month frozen storage before refrigeration (FBR). In the RKC cooked leg meat, the LH temperature significantly affected the TVCP, with LH at 10 °C leading to higher counts, while the Pseudomonas spp. levels were mainly influenced by the freezing, with lower levels in FBR samples compared to their IR counterparts. In the SC cooked leg meat, the LH conditions did not significantly affect the counts, which were instead significantly lowered by the freezing. From an industrial and commercial standpoint, it can be concluded that LH of RKC at high temperature (10 °C) led to a shorter microbial shelf-life of cooked RKC clusters, with the clusters undergoing FBR showing longer microbial shelf-life than their IR counterparts. By contrast, with the mild cooking regime applied, the LH time and temperature of SC had a lower influence on the microbial shelf-life of cooked SC clusters than that given by the choice of the storage type (IR or FBR) after cooking.

A double layer agar plate method results in an improvement for enumerating Vibrio vulnificus and Vibrio parahaemolyticus exposed to nutrient deficiency and refrigeration temperature.

This study sought to І)investigate the effect of varying concentrations of salt on the survival of Gram-negative bacteria in artificial seawater (ASW; pH 6) stored at 4 °C, ІІ)examine the culturable populations of Vibrio vulnificus persisting in ASW with or without 1000 U/mg catalase or 0.1% sodium pyruvate (pH 6) under aerobic and oxygen-restricted environments at 4 °C, and ІІІ)determine whether double layer agar plate (DLAP) methods can improve the culturability of V. vulnificus and Vibrio parahaemolyticus in ASW (pH 6) stored at 4 °C. Once incubated in ASW containing 10% salt at 4 °C, Escherichia coli O157:H7, Salmonella Typhimurium, and Shigella flexneri survived at levels over at least 3.42-4.65 log CFU/mL on day 28, but V. vulnificus underwent the inability to produce colonies within 7 days, while maintaining its membrane integrity. A positive correlation between sodium pyruvate and maintenance of platable colony-forming capability was observed in V. vulnificus incubated aerobically. Using tryptic soy agar containing 3% salt (TSAS) overlayed by thiosulfate-citrate-bile salts-sucrose agar (TCBS), a higher platable colony count of Vibrio spp. was recovered from ASW after 25 or 30 days of storage at 4 °C, followed by TSAS, TSAS overlayed by marine agar (MA), MA, and TCBS.

Influence of Heat Exchanger Design on the Thermal Performance of a Domestic Wine Cooler Driven by a Magnetic Refrigeration System.

Conventional and not-in-kind refrigerators require heat exchangers for their operation. Yet, most magnetic cooling studies do not take full account of those components despite their importance in defining the cooling capacity and temperature span. To investigate the influence of heat exchanger design parameters on the performance of magnetic refrigerators, a model was developed to integrate the heat exchangers, regenerators and thermal reservoirs. The results were compared with data generated in an apparatus that emulates the conditions of the thermal fluid supplied by the regenerators to a cold heat exchanger positioned inside the cabinet of a retrofitted 130-liter wine cooler. Six tube-fin heat exchangers were evaluated to identify the most suitable geometry (number of tube rows and fin density) for the compact magnetic refrigerator. Numerical simulations described the influence of the heat exchanger on the regenerator performance in terms of the liquid stream effectiveness. For a temperature span of 20°C between the external environment and the refrigerated compartment, the best heat exchanger/fan assembly resulted in a cooling capacity reduction of 37\% and a temperature span increase of 32\%, in comparison with an idealized system. The expected system coefficient of performance (COP) and second-law efficiency were 1.8\% and 13\%, respectively.

Inadequate Refrigeration of Some Commercial Foods Is a Continued Cause of Foodborne Botulism in the United States, 1994-2021.

Foodborne botulism is a rapidly progressive potentially fatal paralyzing illness caused by the consumption of botulinum neurotoxin, which is most commonly produced by Clostridium botulinum. Refrigeration is the primary barrier to botulinum neurotoxin production in many processed foods. C. botulinum toxin production has occurred and caused botulism in the United States when foods that were not processed to destroy spores of C. botulinum were stored in an anaerobic environment and not properly refrigerated. We identified 37 cases, including 4 deaths, that occurred during 1994-2021 in the United States from 13 events associated with inadequate refrigeration of commercially produced products. In 11 events, the patient stored the product unrefrigerated at home; in 2 events, a product was kept unrefrigerated at the store before the consumer purchased it. In three events, refrigeration instructions were inadequate or not easily accessible (one label printed on outer but not inner packaging, one label not clearly visible, and one label was not in English). The number of people affected per event ranged from 1 to 16. Using enhanced cost estimates for foodborne botulism cases from a published economic model, these events were estimated to cost >$79M. Potential solutions to this recurring problem include the addition of a secondary barrier, such as an acidifier, to prevent botulinum toxin production, and better labeling to convey risks of refrigerated foods that have not been processed to destroy spores of C. botulinum and to decrease the occurrence of improper storage and handling.