Stages Of Storage Research Articles

Dataset of ultralow temperature refrigeration for COVID 19 vaccine distribution solution

Most COVID-19 vaccines require temperature control for transportation and storage. Two types of vaccine have been developed by manufacturers (Pfizer and Moderna). Both vaccines are based on mRNA and lipid nanoparticles requiring low temperature storage. The Pfizer vaccine requires ultra-low temperature storage (−80 °C to −60 °C), while the Moderna vaccine requires −30 °C storage. However, the last stage of distribution is quite challenging, especially for rural or suburban areas, where local towns, pharmacy chains and hospitals may not have the infrastructure required to store the vaccine at the required temperature. In addition, there is limited data available to address ancillary challenges of the distribution framework for both transportation and storage stages, including safety concerns due to human exposure to large amounts of CO2 from dry-ice sublimation, issues due to the pressure increase caused by dry-ice sublimation, and the potential issue caused by non-uniform cryogenic temperatures. As such, there is a need for test dataset to assist the development of a quick, effective, secure, and safe solution to mitigate the challenges faced by vaccine distribution logistics.

Bacterial Distribution and Community Structure in Beef Cattle Liver and Bile at Slaughter

In this study, the distribution of hygienic indicator bacteria in cattle livers and bile was examined at slaughterhouses. One hundred twenty-seven cattle livers with gallbladders were carefully eviscerated from carcasses at 10 slaughterhouses. Microbiological examination revealed that nine bile samples (7.1% prevalence) and 19 liver parenchyma samples (15.0% prevalence) were positive for Enterobacteriaceae (EB) with means ± standard deviations of 3.68 ± 4.63 log CFU/mL and 1.59 ± 2.47 log CFU/g, respectively; thus, bacterial contamination was apparent even at the postevisceration stage. Subsequently, 70 cattle livers were obtained at the postprocessing and storage stage from 7 of the 10 slaughterhouses. Microbiological analysis revealed significantly higher levels of EB in the liver parenchyma (3.00 ± 3.89 log CFU/g, P = 0.011) than those at the postevisceration stage, suggesting that bacterial dissemination and/or replication occurred in the liver parenchyma during processing and storage. According to 16S rRNA ion semiconductor sequencing analysis of representative samples from 12 cattle, Proteobacteria, Firmicutes, and Actinobacteria were dominant in both the parenchyma and bile in which EB and Escherichia coli were predominant among livers with higher EB levels. These results suggest that bile plays a role as a vehicle for bacterial transmission to the liver parenchyma. This study is the first to evaluate bacterial distribution and community structure in the liver and biliary microecosystem of cattle at slaughter. Our data support the use of EB testing of bile to screen cattle livers contaminated with high levels of fecal indicator bacteria.

COLOR STABILITY OF YOGURT WITH NATURAL YELLOW FOOD DYE FROM SAFFLOWER (CARTHAMUS TINCTORIUS L)

The article elucidates the possibility of using the yellow dye, obtained from saffron petals (Carthamus Tinctorius L.) in the food industry. This powdered dye, added to yoghurt in concentrations of 0.3 – 0.4%, in addition to its yellow color, gives the yoghurt samples a light aroma of saffron flowers and demonstrates high stability during storage at 4° C. for 28 days. The values of the chromatic coordinates, L *, a *, b *, of the yogurt samples did not undergo considerable changes during the storage stage, the color difference ΔE being ≤ 0.79, which indicates a high stability of the dye in yogurt. samples. The chromatic analysis data correlate with the results obtained by the reverse phase HPLC method, which identified the presence of four intact yellow chalcones in the yoghurt. The results of this study will encourage the cultivation of saffron, the extraction of natural dyes and their use in the food industry.

Effect of decreasing dietary crude protein in fattening calves on the emission of ammonia and greenhouse gases from manure stored under aerobic and anaerobic conditions

Dietary strategies can potentially help to reduce nitrogen (N) emissions and decrease the environmental impact of beef production. This study aimed to evaluate the effects of dietary crude protein (CP) concentration on animal performance, N excretion, and manure N volatilisation of finishing Holstein animals. In a first study, 105 Holstein bulls (BW 344 ± 2.6 kg; age 252 ± 0.9 days) were allocated to eight pens to evaluate the effect of two treatments (medium (M) and low (L), which contained CP 14.5% and 12% on a DM basis, respectively) on performance, and results confirmed that dietary CP decrease did not impair animal growth. In a second study, N excretion study, 24 Holstein heifers (BW 310 ± 5.3 kg; age 251 ± 1.4 days) were distributed randomly depending on the initial BW to three treatments (high (H), M, and L, which contained CP 17%, 14.5% and 12% on a DM basis, respectively). Based on N excretion, urinary N excretion was greater (P < 0.001) in H than in M and L diets, but no differences in faecal N excretion were observed among treatments. A third study with in vitro assays under aerobic and anaerobic conditions was designed to analyse gaseous emissions (volatilisation of N and carbon, C) during the storage stage of manure. Manure, faecal and urine samples, mixed at a ratio of 1:1 (wet weight), were collected during the N excretion study (manure-H, manure-M, manure-L). Under aerobic conditions, manure-M and manure-L showed a delay of 4–5 days in manure ammonia emission compared with manure-H (P < 0.01). Total N content was lower (P < 0.01) in manure-L compared with manure-M and manure-H, but N volatilisation (percentage relative to initial N) in manure-L and manure-M was greater (P < 0.01) than in manure-H. In contrast, the anaerobic N volatilisation was 20 times greater in manure-M and 10 times greater in manure-H compared with manure-L. Under aerobic and anaerobic conditions, the emission of C, as C-CO2 and C-CH4, was greater in manure-L than in manure-H and manure-M. Therefore, the decrease of dietary CP concentration from 17% to 14.5% and 12% is an efficient strategy to reduce urinary N excretion by 40%, without impairing performance, and also to reduce manure N losses through ammonia volatilisation under anaerobic conditions. However, a dietary CP content of 14.5% resulted in less environmental impact than a CP content of 12.8% when also considering manure emissions under aerobic or anaerobic conditions.

Federated Learning Approach to Protect Healthcare Data over Big Data Scenario

The benefits and drawbacks of various technologies, as well as the scope of their application, are thoroughly discussed. The use of anonymity technology and differential privacy in data collection can aid in the prevention of attacks based on background knowledge gleaned from data integration and fusion. The majority of medical big data are stored on a cloud computing platform during the storage stage. To ensure the confidentiality and integrity of the information stored, encryption and auditing procedures are frequently used. Access control mechanisms are mostly used during the data sharing stage to regulate the objects that have access to the data. The privacy protection of medical and health big data is carried out under the supervision of machine learning during the data analysis stage. Finally, acceptable ideas are put forward from the management level as a result of the general privacy protection concerns that exist throughout the life cycle of medical big data throughout the industry.

Comparative Analysis of Microbial Community Diversity and Dynamics on Diseased Tubers During Potato Storage in Different Regions of Qinghai China.

Effective storage of potatoes is very important for the food industry. Given the problems involving rotten potatoes and low quality during storage, harvested potatoes from the main potato-producing areas in the Qinghai Plateau were treated by selection and air drying (Group “A”) and the others were stored directly as controls (Group “C”). Then, the microbial community structure and diversity of diseased potato tubers from four main production areas were analyzed by high-throughput sequencing technology in different storage stages. The results showed that the community composition and diversity of microbes in different regions and storage periods were different, and the dominant fungi in diseased potato tubers were Boeremia in Huangyuan (HY), Maying (MY) and Zhongling (ZL) and Apiotrichum in Huangzhong (HZ) at the genus level. The dominant bacterial genus was Pseudomonas, but its abundance varied in samples from different regions and storage periods. In the analysis of indicator species, there were some common species and endemic species in each region and period, and the period with the largest number of different species was the third period. Among the four storage periods, the region with the largest number of different species was HZ. Some fungi, especially Fusarium and other potato pathogens, were more abundant in control Group “C” than in treatment Group “A.” In the diversity analysis, the α diversity of fungi in Group “C” was higher than that in Group “A,” but the α diversity of bacteria in Group “A” was higher than that in Group “C,” and there was no obvious regularity with storage time. The β diversity varied significantly among different regions. In addition, through functional prediction analysis, it was found that a plant pathogen was one of the main nutritional types of fungi, which indicated that treatment by selection and drying could significantly reduce phytopathogenic microbe and other microorganisms and could be used as an effective measure for potato storage compared with the prevention and control by drugs that can cause environmental pollution. Further analysis of co-occurrence network showed that pathogenic fungi Fusarium was negatively correlated with pathogenic bacteria Erwinia, and there is also a negative correlation between pathogens and antagonistic microorganisms indicated that there were various symbiotic relationships among microorganisms in diseased potatoes. This study may provide a theoretical basis for biological control of potato cellar diseases and the maintenance of potato quality during long-term storage.

Short-term hypobaric treatment alleviates chilling injury by regulating membrane fatty acids metabolism in peach fruit.

Short-term hypobaric treatment (SHT) on postharvest quality and membrane fatty acids metabolism were studied in peach fruit (Prunus persica [L.] Batsch., cv. Feicheng) during shelf life after cold storage. SHT was effective in alleviating chilling injury (CI) and maintaining postharvest quality. SHT reduced the production of malondialdehyde (MDA) and electrolyte leakage (EL), and increased membrane fluidity. In addition, SHT plays an imperative role in reducing saturated fatty acid (SFA), increasing unsaturated fatty acid (USFA), and keeping a higher unsaturation level in peach fruit. Meanwhile, SHT enhanced the activity of fatty acid synthetase (FAS), upregulated the expression levels of FAD2, FAD3-1, FAD3-2, and FAD7 genes at the early stage of storage, as well as inhibited the activity of lipoxygenase (LOX) and gene expression of LOX1. These results suggested that SHT could increase fatty acids unsaturation by regulating FAS activity, FAD and LOX1 gene expression, thus maintain high membrane stability and alleviate CI. PRACTICAL APPLICATIONS: CI is an important factor affecting the postharvest quality of peaches in cold storage, and metabolism of membrane fatty acids is one of the main CI response mechanisms. Our previous study has shown that SHT could alleviate CI in peach fruit. Therefore, it is of great significance to investigate the regulation of membrane fatty acids metabolism under SHT. Results from this study suggest that the enhancement of chilling tolerance by SHT in peaches could be explained, at least in part, as being due to enhanced FAS activity, upregulated the expression of FAD gene, and inhibited LOX1 to maintain higher unsaturation level. All in all, we explored the response mechanism of membrane fatty acids metabolism under SHT in peach fruit, and supplied theoretical guidance for application of the technology.

Effects of irradiation on the multi-field coupling delayed hydride cracking behavior of zirconium alloys

With high mechanical strength, good corrosion resistance and small thermal neutron absorption cross-section, zirconium based alloys are widely used as the nuclear structural materials. Stress concentration usually appears in zirconium-based-alloy components during their reactor service phase or the storage stage of spent fuels, which could induce the delayed hydride cracking (DHC) behavior to seriously threaten the nuclear safety. In this study, an innovative multi-field coupling theoretical frame is developed, with the effects of texture factor, with the irradiation hardening and embrittlement effects as well as the hydride orientation contributions involved in the cohesive model, with the hydrogen diffusion affected by the irradiation-induced variations of Nb concentration. The multi-field coupling simulation results indicate that (1) the predictions of the DHC velocities for different irradiation doses are in good agreement with the experimental data, and the subcritical cracking traits can be captured, which validates the effectiveness of the newly developed models; (2) the irradiation-enhanced hydrogen diffusion coefficient plays a dominant role in the increase of DHC velocity with the radiation dose; (3) the irradiation hardening leads to the increases of hydrostatic stress gradient and the concentration gradient of solid-soluted hydrogen atoms, which accelerates the diffusion flux of hydrogen atoms towards the crack tip region; (4) essentially, it is the irradiation hardening that shortens the required length of hydrided zone to initiate new fracture, and quicken the multi-coupling cracking process. This work lays a foundation for the further study of delayed hydride cracking behavior.

Preparation and thermal performance of a novel alloy microencapsulated phase change material (MEPCM)/ceramic composite

Phase change material (PCM)/ceramic composite is qualified to be a novel composite thermal energy storage (TES) material, which can simultaneously utilize the latent heat of phase change materials and sensible heat of ceramic matrix materials to accomplish the storage and release of thermal energy. It exhibits a wide application prospect in the field of medium and high temperature thermal energy storage. However, based on the ceramic porous adsorption PCM, there is still the risk of leakage after the PCM melts in the thermal energy storage stage. In this paper, SnBi58 alloy microencapsulated phase change material (MEPCM) with high thermal reliability was prepared by “double-layer coating, sacrificing inner layer” method, which a thermal expansion void was constructed to accommodate volume expansion of PCM. On this basis, SnBi58 alloy MEPCM/ceramic composite was prepared by the cold-pressing sintering method and its thermal performance was studied. The experimental results show that SnBi58 alloy MEPCM/ceramic composite does not leak at the MEPCM/Matrix mass ratio of 2.5:1, but SnBi58 alloy/ceramic composite leaks at the SnBi58 alloy/Matrix mass ratio of 1.5:1, indicating that SnBi58 alloy MEPCM has good thermal reliability and leak resistance. In addition, compared with the ceramic matrix material, the latent heat of MEPCM/ceramic composite with a mass ratio of 2.5:1 is increased by 30.24 J/g and the thermal conductivity reaches 2.853 W/(m·K), which is 3.67 times of the matrix material. Furthermore, thermal performances of four MEPCM/ceramic composite with different proportions were tested and compared, including thermal conductivity, thermal response curve and infrared thermal imaging. The results show that the higher the proportion of MEPCM, the better the thermal performance of the MEPCM/ceramic composite. Moreover, to predict the thermal conductivity of the novel composites, six thermal conductivity models were compared based on the experimental results, and the results show that the prediction error of Maxwell-Eucken is the smallest which can be used to predict the thermal conductivity of MEPCM/ceramic composite. Finally, the thermal reliability of the composite was tested. The results of DSC and XRD showed that the thermal properties and chemical structure basically have no change before and after thermal cycling. MEPCM/ceramic composite has excellent thermal reliability.

Morphophysiology and cryopreservation of seeds of Dendrobium nobile Lindl. (Orchidaceae) at different stages of development

The immature seeds of Dendrobium nobile acquire resistance to freezing and long-term storage in a cryobank at the age of 6 months after pollination. Seed maturation of Dendrobium nobile Lindl to establish the optimal stage for long-term storage of immature seeds in liquid nitrogen was studied. Immature seeds can germinate in vitro starting from 3 months after pollination (MAP) but only develop up to the stage of embryo swelling or protocorm without rhizoids. The maximum staining of embryos with vital dyes FDA and TTC occurs at 4 and 5 MAP that corresponds to the release of suspensor beyond the embryo sac. Embryo staining does not correlate with germination capacity and seed viability in cryogenic storage. The immature seeds acquire resistance to drying in airflow and cryostorage at the age of 6 MAP. 11% of seeds germinated after cryogenic storage at 6 MAP, and 81–94% at 7–10 MAP.

Analysis of post-harvest losses of banana and the economic wellbeing of farmers in Boyo Division, North West Region of Cameroon

Post-harvest losses of banana affect the economic wellbeing of farmers in Africa especially in Boyo Division in the North West region of Cameroon where majority of the producers are smallholders’ farmers. The study analysed post-harvest losses of banana and its effect on the economic wellbeing of farmers in Boyo Division. Three hundred and eighty respondents were selected from three out of four sub-divisions in Boyo Division using a multi-stage sampling procedure. Data was obtained from the respondents with the aid of questionnaire and focus group discussions. The data obtained was analysed using descriptive statistics. The results revealed that 61,055 bunches of banana were harvested, 21,107 bunches sold, 16,751 bunches used by farmers’ households while 23,197 bunches were lost at post-harvest stages in 2019/2020. This quantity lost was suffered at the farm level, transportation, storage, ripening, processing and sale stages with most losses (11-20) suffered at the farm level. The study further revealed that farmers expected an estimated net amount of 10,570,036 FCFA while an estimated net amount of 2,213,759 FCFA was achieved with post-harvest losses. The study therefore, concludes that post–harvest losses of banana have a positive correlation on farmers’ economic wellbeing and recommends sensitization and training of farmers on post-harvest management techniques.

Метод биометрической аутентификации на основе кепстральных характеристик эхограмм наружного уха и нейросетевого преобразователя биометрия-код

Open biometric images (fingerprint, iris, face) are "in sight" and therefore compromised in the natural environment. In this work, it is proposed to use data on the internal structure of the outer ear obtained using echography as biometric images. The individual characteristics of the ear canal of subjects are hidden from direct observation and cannot be copied by photographing. The proposed authentication method is based on cepstral analysis of echograms of the ear canal using neural network biometrics to code converters, trained in accordance with GOST R 52633.5. The neural network biometrics-code converter allows you to associate a user's cryptographic key or password with his biometric image. This is a shallow neural network of one or two layers of neurons, which is configured to generate a key specified during training when an image of a known user arrives, and when an unknown image arrives at its inputs, generate a random code with high entropy. At the entrance to this network, cepstral signs of echograms were received. To apply the method in practice, you need a special device that combines a headphone with a sound-proof housing and a microphone. The results obtained can be called optimistic EER = 0.031 (FAR = 0.001 at FRR = 0.23). The use of neural network converters biometrics-code showed a relatively higher percentage of errors in comparison with multilayer neural networks and the naive Bayes classification scheme, however, neural network biometrics to code converters allows you to implement authentication in a protected mode. This means that the subject's biometric data will be protected from compromise at the stages of storage, execution and transmission via communication channels.

Experimental Investigation of Phase Behavior of Condensate Gas and Crude Oil System in Underground Gas Storage

Abstract The phase behavior of reservoir fluids is crucial for the smooth operation of an underground gas storage (UGS). In this work, three experiments were conducted to investigate the phase behavior of condensate and crude oil systems within different development stages of gas storage in Bohai Bay Basin of eastern China. In stage 1, constant volume depletion (CVD) test was conducted to simulate the interaction of the original condensate gas-live oil system. In stage 2, the phase behavior of a series of mixtures of live oil with 47.5, 58.3, 69.9, and 77.4 mol% of condensate gas was studied by constant composition expansion (CCE) test. In stage 3, a new experiment was designed to study the mass transfer and phase behavior during cyclic injection-production process of the underground gas storage. The results from the CVD test describe the effect of each pressure stage on produced gas composition and equilibrium oil properties in the condensate crude oil system. The results of the CCE test indicate that condensate gas can expand the oil and improve the properties. The results of cyclic injection-production experiment demonstrate that the mass transfer in condensate gas and oil system is a dual mechanism of condensation and vaporization. With the increase of the cycle, the intermediate components of oil phase are enriched and the heavy components decreases. After four cycles, the oil and gas interphase mass transfer reaches dynamic equilibrium. In addition, test results show that multicycle operation is beneficial to improve the oil properties. This work is of great significance to understand the phase transition mechanism of underground gas storage, which provides a basis for other researchers to further update and improve the EOS model.

Effects of 1-methylcyclopropene (1-MCP) treatment on ethanol fermentation of Nanguo pear fruit during ripening.

The aim of this study was to analyze the effects of 1-methylcyclopropene (1-MCP) on ethanol fermentation of Nanguo pears during ripening. Pears were exposed to 1µl/L 1-MCP and stored at 20±2°C. Our data indicated that postharvest application of 1-MCP maintained flesh firmness and reduced ethylene production and respiration rate during storage compared with untreated fruits. 1-MCP treatment delayed the second glucose peak during fruit ripening. The contents of pyruvate and acetyl-CoA were generally reduced by 1-MCP treatment, and at the same time, their peaks were delayed by it during storage compared with controls. The contents of citric acid (CA) and oxaloacetate (OA) were increased by 1-MCP, whereas the contents of acetaldehyde and ethanol were reduced during the whole storage period compared with controls. Activities of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) were reduced by application of 1-MCP during the early stage of storage, and the appearance of their peak activities was also delayed after treatment with 1-MCP. These data showed that postharvest application of 1-MCP could effectively delay the production of the "alcohol taste" of Nanguo pears during ripening. PRACTICAL APPLICATIONS: Nanguo pear is one of the most common cultivars that widely grow in northeast China. It is preferred by many consumers for its unique "alcohol taste", which is mainly produced through ethanol fermentation during ripening. Until now, the mechanisms for regulating ethanol fermentation in ripening Nanguo pears are still unclear. Our data indicated that postharvest application of the ethylene action inhibitor 1-MCP could effectively delay the production of the "alcohol taste" of Nanguo pears during ripening. The data from this study can provide reference data for maintaining the quality of postharvest Nanguo pears.

Research on the Water Production Tracking Method of Horizontal Well in Heavy Oil Reservoir with Bottom Water

Abstract At present, the model of heterogeneous fluid production in horizontal wells in bottom water reservoirs does not comprehensively consider the influence of parameters such as flow, length, and position of each production section, resulting in the distortion of interpretation results. Using the Green function and the Newman product method, this paper derives heterogeneous fluid production in horizontal wells in the bottom water heavy oil reservoir. The Stehfest numerical inversion algorithm was used to obtain the bottom fluid pressure solution of the horizontal well production in the bottom water heavy oil reservoir with the wellbore storage effect and skin effect. By drawing the typical chart of horizontal well test in sections, the new model can be divided into five typical flow stages: wellbore storage stage, transition stage, radial flow stage, linear flow stage, and late stable flow stage. Based on the interpretation of conventional parameters, such as permeability, well storage, and skin effect, the new model can further diagnose the parameters such as liquid production length, liquid production position, and liquid production volume of each horizontal section. The field application examples verify the validity of the research results and broad application prospects.

Effects of Harvest Stage, Storage, and Preservation Technology on Postharvest Ornamental Value of Cut Peony (Paeonia lactiflora) Flowers

Herbaceous Peony has high ornamental value but short flowering period, which limits the development of the cut flower industrialization. We studied the effects of different harvest stages, pre-treatment solutions, storage methods, and preservation solutions, including different carbon sources on the ornamental of cut Paeonia lactiflora flowers. The results showed that the “Open-top type” peony had the highest flowering rate and longer vase life harvested at the soft-bud (SB) stage, and the “unfold-petal type” peony collected at the changing-color (CC) stage had the highest flowering rate and the best vase ornamental. In addition, the vase effect of cut peony pre-treated with 8-hydroxyquinoline (8-HQ) and nanosilver (NS) was better than that of the control, and the decline of related protective enzyme activity slowed down in the later stage of storage. The protective enzyme activity of cold storage and low oxygen (CS + LO) treated cut flowers was higher than that of cola storage (CS) treated cut flowers. Apparently, in the fresh-keeping solution containing glucose, sucrose, and trehalose, the flower diameter of cut flowers increased, and the vase life was prolonged, among which the increase of flower diameter treated with glucose was the most significant, and trehalose can delay flowering, increase flowering period, and delay aging.

Research on the temperature field of grain piles in underground grain silos lined with plastic

AbstractTo investigate the temperature change in grain piles during underground grain storage, this study considers high‐moisture grain, and uses a combination of experiments and numerical simulation to study the change in the temperature field in the underground bin during the static storage and mechanical ventilation phases. The results show that during the static storage stage, grain respiration is strong. The grain pile first begins to heat up at the bottom and gradually forms a high‐temperature heat core; in the mechanical ventilation stage, the grain pile first cools down from the air outlet, and then gradually spreads to the entire silo. Inside, the study found that the diffusion path is related to the air duct setting. After being ventilated for 10 hr, the grain pile temperature in the test silo fell below 10°C from the middle to the bottom of the silo, and only reached 15°C above the return air outlet near the grain‐loading line. An increase in air supply accelerates the temperature decrease in the grain pile; the difference in the initial state of the grain pile has little effect on the cooling effect of mechanical ventilation. In the experiment and simulation, the mechanical ventilation adopts a uniform air supply method, which has a significant effect on reducing the grain pile temperature in the silo.Practical ApplicationsIn this study, a test platform is established for an underground silo lined with plastic. By monitoring the temperature in the test silo, the dynamic temperature changes in the grain pile can be analyzed, and the results are compared with the numerical simulation results to verify the model reliability. The temperature field simulation of grain piles under different conditions lays the foundation, and at the same time provides a basis for formulating relevant measures to achieve safe grain storage.

Finite time thermodynamics analysis and research of pulsating heat pipe cold storage device

Phase change energy storage technology can effectively solve the energy mismatch in space and time. There are many disadvantages of phase change materials (PCMs), such as high supercooling, phase separation and poor heat transfer performance. As a new type of heat exchange structure, pulsating heat pipe has the advantages of simple structure, high heat transfer coefficient and good economic behavior. The system efficiency can be greatly improved by using pulsating heat pipe combined with cold storage technology. A set of pulsating heat pipe type cold storage device is developed, the finite time thermodynamic analysis is carried out, and the correlation between heat pipe efficiency and power is established. The three-dimensional physical model of pulsating heat pipe is simulated and verified by experiments. The experimental results show that in the cold storage stage, with the increase of the filling rate, the greater the pressure is, the better the heat transfer effect is; in the cold release stage, with the decrease of the filling rate, the smaller the pressure is, the better the heat transfer effect is.

Postharvest quality and reactive oxygen species metabolism improvement of Coprinus comatus mushroom using allyl isothiocyanate fumigation

Abstract The aim of this study was to evaluate the effect of allyl isothiocyanate (AITC) on the reactive oxygen species (ROS) metabolism and quality of postharvest Coprinus comatus (C. comatus). Fresh mushrooms were stored at 4 °C with AITC at 5, 10, and 20 μL/L for 18 d, respectively. Sampling was performed every 3 d, and physicochemical parameters and ROS metabolism related enzymes activities were analyzed. Compared with the control, the application of AITC at 10 μL/L significantly (P&amp;lt;0.05) decreased xanthine oxidase activity after 9 d of storage, while it significantly (P&amp;lt;0.05) improved the activities of succinic dehydrogenase, glutathione reductase, peroxidase, catalase, and ascorbate peroxidase in the middle and later stages of storage. Furthermore, the Ca2+-ATPase and superoxide dismutase activities in sample treated by 10 μL/L were all significantly (P&amp;lt;0.05) higher than those in the control. Therefore, the accumulation trends of malondialdehyde and ROS were retarded and membrane integrity was maintained. However, high-concentration AITC (20 μL/L) treatment accelerated the ROS generation and increased electrolyte leakage rate. All AITC treatments significantly (P&amp;lt;0.05) inhibited the respiration rate during the first 9 d of storage and retarded browning of C. comatus during the storage of 18 d. These findings suggested that AITC treatment would be a promising method to maintain C. comatus quality, but the concentrations need to be optimized.

Amino acid composition of meat raw materials during long-term cold storage

The results of studies on the study of changes and quantitative assessment of the content of amino acids in meat raw materials during long-term cold storage are given. At the same time, it was established that the mass fraction of protein in the studied samples of raw meat stored in industrial conditions changed slightly during the entire period of storage. The results of the research on the storage of frozen meat showed that the test samples of beef and pork at the last storage period (180 days) contained essential amino acids, i.e. were complete and had quite high indicators of biological value, close to the norm recommended by FAO/WHO. The most significant decrease in essential amino acids: methionine and cysteine was noted in beef samples. At the last stages of storage, an almost 2-fold increase in proline content was observed in both beef and pork, which may indicate a possible effect of freezing and subsequent cold storage. During refrigerated storage of frozen meat, the NAC/ZAB ratio after 6 months of storage was 1.85 and 1.68 for pork and beef, respectively, which in turn is slightly different from proteins with high biological value. The ratio of the group of essential amino acids to the group of replaceable ones (amino acid index NAK/ZAK) in the studied samples of beef and pork was 0.59...0.67 – for beef and 0.62...0.75 – for pork, respectively, which is close to the value of this indicator. recommended by FAO/WHO for a balanced diet – 0.56...0.67. The amino acid index of the ratio of essential amino acids to total amino acids for the "standard" protein has a value of 0.4, in the samples we examined it was 0.37...0.4 – for beef and 0.38...0.42 – for pork, which also shows fairly high biological value of meat after long-term storage in a frozen state. The main influence on the change of protein substances of meat and the amino acid composition associated with them is provided by the process of freezing, which results in denaturation and aggregation of proteins, further storage of meat in a frozen state has a lesser effect on the changes taking place in it.