Refrigeration Conditioning Research Articles

Enhancing the Thermophysical Properties of Lubricating Oils of Refrigeration System Using CuO/CeO2 as a Mixture of Nanoparticles

The compressor is the heart of the refrigeration system, extension of its life and preservation of its moving parts such as pistons, rotors, valves, connecting rods and cranks lubrication require improvement. Recently the studies focus on the use nanoparticles with lubricants in refrigeration and air conditioning systems in view of their significant impact on improving the coefficient of performance of these systems as well as thermophysical properties of pure lubricating oils and thus reducing energy consumption. In this study, nanoparticles were synthesized in an easy and cheap way and from materials available in chemistry laboratories as following copper oxide, cerium oxide, mixture 1 consisted of 50% copper oxide with 50% cerium oxide, mixture 2 consisted of 60% copper oxide with 40% cerium oxide, mixture 3 consisted of 70% copper oxide with 30% cerium oxide, mixture 4 consisted of 40% copper oxide with 60% cerium oxide, and mixture 5 consisted of 30% copper oxide with 70% cerium oxide to study their effectiveness on enhancing the thermophysical properties of POE, PAG lubricating oil using mathematical equations available from earlier studies. The results obtained from the mathematical equations showed an increase in the viscosity of POE from 40 mm2/sec to 45 mm2/sec at 0.05 wt.% and reached 108.86 mm2/sec by increasing the concentration of nanoparticles to 0.33wt.%, as well as the improvement of viscosity of PAG from 46 mm2/sec to 52.9 mm2/sec at the concentration of nanoparticles 0.05 wt.%, recording a significant improvement when the concentration of nanoparticles reached 0.33 wt.%, as well as for the rest of the other physical properties. This is consistent with earlier studies that confirmed the improvement of the physical properties of lubricants through mixing them with nanoparticles.

Performa Termal Kondensor Udara pada Wind Tunnel: Evaluasi Perpindahan Panas

Heat transfer in air condenser systems is a critical aspect in various industrial applications, especially refrigeration and air conditioning systems. The thermal efficiency of condensers is greatly influenced by airflow characteristics, but airflow velocity optimization remains a challenge due to the trade-off between improved heat transfer and energy consumption. Although previous research has examined various aspects of condenser design, there is still a need to explore the optimal limit of airflow velocity that can maximize thermal efficiency without excessively increasing system workload. This study aims to evaluate the thermal performance of an air condenser in a wind tunnel, focusing on the effects of airflow velocity variations on heat transfer rate and thermal efficiency. The experimental method uses a wind tunnel with dimensions of 280x28x28 cm, equipped with a precise temperature and flow velocity measurement system. The flow velocity was varied from 0.8 to 1.8 m/s. The results showed a significant increase in the heat transfer coefficient (h) and heat transfer rate (Q) as the flow velocity increased. Analysis of Reynolds and Nusselt numbers revealed the transition of the flow from laminar to turbulent, which contributed to the increase in heat transfer efficiency. Comparison of experimental results with simulations showed good agreement in the middle velocity range, but there were deviations at extreme velocities. In conclusion, increasing the airflow velocity proved effective in improving the thermal performance of the condenser, but further optimization is required to balance the thermal efficiency with the energy consumption of the system.

Performance Predictions of Solar-Assisted Heat Pumps: Methodological Approach and Comparison Between Various Artificial Intelligence Methods

The coefficient of performance (COP) is a crucial metric for evaluating the efficiency of heat pump systems. Real-time monitoring of heat pump system performance necessitates continuously collecting and processing data from various components utilizing multiple sensors and controllers. This process is inherently complex and presents significant challenges. In recent years, artificial intelligence (AI) models have increasingly been applied in refrigeration, heat pump, and air conditioning systems due to their capability to identify and analyze complex patterns and data relationships, demonstrating higher accuracy and reduced computation time. In this study, multilayer perceptron (MLP), support vector machines (SVM), and random forest (RF) are used to develop COP prediction models for solar-assisted heat pumps. By comparing the predictive accuracy and modeling time of the three models built, the results demonstrate that the random forest model achieves the best prediction performance, with a mean absolute error (MAE) of 2.42% and a root mean squared error (RMSE) of 4.01% on the train set. On the test set, the MAE was 2.35% and the RMSE was 3.84%. The modeling time for the RF model was 6.57 s.

Performance of vibration and current signals in the fault diagnosis of induction motors using deep learning and machine learning techniques

Induction motors (IMs) play a pivotal role in various industrial applications, powering critical systems such as pumps, compressors, fans, blowers, and refrigeration and air conditioning systems. Monitoring the health of these IMs is essential for ensuring reliable operation. Numerous sensors, including vibration, current, temperature, acoustic, and power sensors, can be employed for their health monitoring. This article conducts a comprehensive comparative analysis of two widely used sensors—vibration and current, for classifying different health states of IMs, such as a healthy condition, bearing fault, and misalignment. The study employed deep learning techniques, specifically 1D and 2D convolutional neural networks, trained on raw data. Additionally, machine learning techniques, including random forest and XGBoost, were utilized and trained on features derived from preprocessed signals using fast Fourier transform and discrete wavelet decomposition. Comparative results indicated that vibration signals achieved remarkably high accuracy, nearly 100%, in detecting the investigated mechanical faults, while current signals, after signal processing and manual feature extraction, achieved an accuracy of 87.41%. These results demonstrate that, though current sensors are a viable alternative to vibration sensors, their performance can be affected by the type and degree of the considered faults. This study also highlights the attributes of vibration and current signals in the health monitoring of rotating machinery such as IMs.

Enhancing grape preservation: The synergistic effect of curry leaf essential oil in buckwheat starch-chitosan composite coatings

A novel edible composite coating composed of buckwheat starch (BS) and chitosan (CH) with varying levels of curry leaf essential oil (CLEO) was synthesized in the present study. Initially, starch was extracted from buckwheat groats, and its proximate analysis revealed a high amylose content (21.91 ± 0.32%), which makes it an excellent base material for coating formation. The composite coatings were created by blending BS and CH with CLEO in different concentrations. The coatings underwent a comprehensive evaluation, including physico-chemical, functional, thermal analyses, and microstructural characterization. Cytotoxicity tests on human cell lines (Caco-2) confirmed that the coatings were non-toxic. Among the various formulations, the coating with 2.0% CLEO (referred to as F5) exhibited the highest antimicrobial activity, maximum antioxidant properties, and the lowest water solubility. Following this, the coatings were applied to green grapes (Vitis vinifera) via dip coating technique. The performance of coatings was assessed by storing the grapes under room temperature (25 ± 1 °C) and refrigeration conditions (4 ± 1 °C). From visual appearance and physio-chemical tests, it was concluded that the F5 coating was potentially active in extending the shelf life of grapes to 12 days at room temperature and to 20 days under refrigeration storage. Overall, the BS-CH-CLEO composite coating emerges as a refined and eco-conscious bioactive packaging solution, elegantly extending the shelf life of grapes while providing both sustainability and cost-efficiency.

Influence of storage time of fermented soghurt on the changes in fat and protein biomolecules through Confocal Laser Scanning Microscopy (CLSM) under refrigeration condition

The aim of the study is to assess the significance of storage duration on fermented Soghurt (soy curd), focusing on changes in fat and protein biomolecules analyzing with CLSM, viscosity measurements, and particle size distributions under refrigerated conditions. Soghurt prepared with 1% yogurt culture (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) was analyzed for storage stability under refrigerated conditions for up to 15 days measuring the pH, acidity, microbial counts, viscosity, particle size distribution and scanning electron microscopy for structural analysis. Even though lactic counts were not affected significantly during the storage periods, yeast & mold counts and coliform counts were absent up to 15 days during the storage. However, the product could be stored upto 7 days under refrigeration condition (6–8 °C). During the storage period, it was observed that the viscosity of soghurt increased with increase in storage time. Particle size distribution was estimated during the entire storage periods for soghurt and it was observed that smaller particle was mostly found in the range of 3.0–50.0 µm while bigger particles were in the range of 57.0–910.0 µm. Further, larger aggregates with big particle sizes were observed during prolonged storage period. The CLSM study showed the appearance of proteins and fats being dispersed slowly during the storage due to the proteolytic and lipolytic activities of yoghurt cultures after 5 days of storage under refrigeration condition.

Spontaneous gradient copolymers of N-vinylsuccinimide/N-vinylsuccinamic acid with O-cholesteryl (meth)acrylate via RAFT polymerization as potential drug delivery systems

Today, biocompatible and bioinspired well-defined copolymers with the ability to form nanoparticles are of great interest as potential drug delivery systems. In this study, we report the synthesis of novel biocompatible copolymers from monomers with different activity and capable of forming gradient copolymers by RAFT polymerization. In particular, the copolymerization of N-vinylsuccinimide (VSI) and O-cholesteryl (meth)acrylate (Ch(M)A) mediated by S,S’-dibenzyl trithiocarbonate (DBTTC) has been thoroughly studied by varying the monomer ratio and the ratio of monomer to RAFT agent. Important dependencies such as molecular weight and monomer conversion versus time, and molar fraction of monomer units as a function of monomer conversion were investigated. The obtained copolymers were thoroughly characterized using a number of physicochemical methods such as 1H NMR, 1H–13C HSQC and ATR-IR-spectroscopy, size-exclusion chromatography, static and dynamic light-scattering, as well as thermogravimetric analysis. In addition, the reactivity ratios of VSI and ChMA were determined and the dyad and triad compositions of the copolymers were calculated from the obtained values. The synthesized P(VSI-co-Ch(M)A) were subjected to selective hydrolysis of succinimide ring to convert it into succinamic acid. This approach yields a set of bioinspired amphiphilic copolymers based on N-vinylsuccinamic acid (VSAA) and Ch(M)A. The synthesized series of P(VSI-co-Ch(M)A) and P(VSAA-co-Ch(M)A) were used to obtain nanoparticles by nanoprecipitation or self-assembly via direct dissolution in aqueous medium. In addition, the method of surface hydrolysis of VSI units in pre-formed P(VSI-co-Ch(M)A) nanoparticles was applied to produce nanoparticles with hydrophilic negatively charged surface and enhanced stability. All techniques were optimized to prepare nanoparticles with characteristics suitable for systems considered for drug delivery. Successful loading of the antitumor drug irinotecan into nanoparticles was achieved with high encapsulation efficacies. The storage stability of empty and irinotecan loaded nanoparticles were studied in various media (water, saline solution, serum containing cell culture medium) under room and refrigerator conditions. The developed empty nanoparticles exhibited low rate of uptake by macrophages and low cytotoxicity to irinotecan-sensitive colon cancer cells (Caco-2). In turn, the irinotecan-loaded nanoparticles demonstrated inhibitory activity against Caco-2 cells comparable to the free drug.

Hemp cellulose-based aerogels and cryogels: From waste biomass to sustainable absorbent pads for food preservation

This study presents a circular economy approach utilizing hemp stems and rice straw, typically perceived as low-value agricultural waste, to develop a sustainable alternative to traditional plastic absorbent pads for food packaging. The development of an active material was achieved through the utilization of hemp cellulose and a bioactive extract isolated from rice straw. In addition to reducing plastic pollution, this material demonstrates the potential to enhance food preservation. This research provides evidence of the benefits of repurposing agricultural by-products to create valuable and environmentally-friendly products. Hemp cellulose was extracted, characterized, and processed to develop stable aerogels and cryogels through supercritical CO2 drying and freeze-drying. The water stability and internal structure of the materials were guided via TEMPO-mediated oxidation and high-pressure homogenization. Both materials showed versatile physicochemical and mechanical properties. Nevertheless, with higher water sorption (2.20 mL/g), minimal dimensional changes, and lower shrinkage, cryogels were suitable for meat absorbent pad application. To enhance the cryogels functionality, they were impregnated with a rice straw bioactive extract in two different concentrations. The incorporation of the extract did not affect the structure of the cryogels, improved their mechanical properties and the antioxidant activity remained stable after drying (63.89–78.96 %). Finally, the performance of the developed materials was compared to commercial plastic pads and pristine meat preservation challenge test during 9 days at refrigeration conditions. The incorporation of rice straw extract improved meat color preservation. While moderate extract concentrations (75 mg/g) showed a protective effect against lipid oxidation, higher levels (187.5 mg/g) induced pro-oxidant reactions. This research highlights the potential of hemp cellulose-based cryogels as sustainable and functional packaging materials for meat products.

An Analytical View on the Use of Flucloxacillin for Outpatient Parenteral Antimicrobial Therapy.

Although the addition of buffers provides improved stability to flucloxacillin (FLU) solutions, unbuffered solutions are often preferred in clinical practice. The first purpose of this study was to investigate whether a 50 mg/mL solution of FLU in normal saline is stable for 24 h at 33 °C so that it can be applied for outpatient parenteral antimicrobial therapy (OPAT) using portable elastomeric infusion pumps (PEIPs). When the PEIPs were stored in an oven at 33 °C and deflated over 24 h, the volume of the collected solution, pH, and FLU concentration were checked every 4 h. Obtaining better results than expected based on the literature data, other storage conditions, such as refrigeration, room temperature (RT), 37 °C, refrigeration followed by 24 h at 33 °C and 37 °C, and different batches/brands, were also tested. This study confirmed the pronounced effect of temperature on the stability of FLU and also showed the relationship between the stability of FLU and the initial pH of the solution. FLU was quite stable at refrigeration and RT conditions, with more than 99% and 95% remaining. After 24 h at 33 °C, more than 92% of FLU was still present in the solution, while this number decreased to less than 85% when the storage temperature reached 37 °C. The remaining percentage was found to be even lower when the solution was stored at 2-8 °C for 6 days, followed by 24 h storage at 33 °C or 37 °C, with losses of 17% and 30%, respectively. The stability of FLU became worse when the initial pH of the solution was lower than 5.9 since the concentration of FLU dropped to less than 90% after 24 h at 33 °C, and a precipitate started to form when the initial pH of the solution was around 5.3. Therefore, FLU in PEIPs could be employed for 24 h if the temperature was ideally not more than 33 °C, while the pH should be not less than 5.9 upon reconstituting the FLU solution.

Comprehensive Optimization of a Freeze-Drying Process Achieving Enhanced Long-Term Stability and In Vivo Performance of Lyophilized mRNA-LNPs

The success of mRNA vaccines against SARS-CoV-2 has prompted interest in mRNA-based pharmaceuticals due to their rapid production, adaptability, and safety. Despite these advantages, the inherent instability of mRNA and its rapid degradation in vivo underscores the need for an encapsulation system for the administration and delivery of RNA-based therapeutics. Lipid nanoparticles (LNPs) have proven the most robust and safest option for in vivo applications. However, the mid- to long-term storage of mRNA-LNPs still requires sub-zero temperatures along the entire chain of supply, highlighting the need to develop alternatives to improve mRNA vaccine stability under non-freezing conditions to facilitate logistics and distribution. Lyophilization presents itself as an effective alternative to prolong the shelf life of mRNA vaccines under refrigeration conditions, although a complex optimization of the process parameters is needed to maintain the integrity of the mRNA-LNPs. Recent studies have demonstrated the feasibility of freeze-drying LNPs, showing that lyophilized mRNA-LNPs retain activity and stability. However, long-term functional data remain limited. Herein, we focus on obtaining an optimized lyophilizable mRNA-LNP formulation through the careful selection of an optimal buffer and cryoprotectant and by tuning freeze-drying parameters. The results demonstrate that our optimized lyophilization process maintains LNP characteristics and functionality for over a year at refrigerated temperatures, offering a viable solution to the logistical hurdles of mRNA vaccine distribution.

Simulation analysis and optimization of thermoelectric refrigeration and air conditioning

Abstract Thermoelectric refrigeration technology is mainly through the Peltier effect to achieve refrigeration, thermoelectric refrigeration air conditioning needs to be combined with a certain air flow rate to realize the separation of cold and heat, and make full use of the cold end to realize the refrigeration function, or else the refrigeration efficiency is seriously affected. Based on the ICEPAK simulation platform of ANSYS, we analyze the influence of structure and parameter settings on the conversion efficiency of thermoelectric refrigeration air conditioning fan under the established boundary conditions, establish the relationship between air flow rate and temperature drop value, and put forward the optimization of the product structure design scheme, and the results of the optimization scheme show that there is a peak in the operating current at a certain heat dissipation efficiency; and lengthening the length of the air ducts through the optimization of the structure can enhance the refrigeration effect of the air conditioner.

Assessment of lyophilized microencapsulated multi strain probiotic for improved shelf life and stability

A Multi species Probiotics (MSP) of calf gut origin was encapsulated either with chitosan (ECMSP) or without chitosan (EMSP). Further, the probiotic was encapsulated and lyophilized (ELMSP) using three types of cryoprotectant solutions sucrose (ELMSP(S)), skim milk (ELMSP(SM)) and sucrose + skim milk combination (ELMSP (SSM)). The encapsulation yield was good and ranged from 75 % to 80 % for MSP products. These MSP products were stored at refrigeration temperature (4 °C), deep freeze and room temperature for 12 weeks. The shelf life (mean CFU) of encapsulated microcapsules was significantly better (P < 0.001) at the refrigeration temperature (9.44 Log10 CFU/g) than deep freeze (7.42 Log10 CFU/g) and room temperature (6.67 Log10 CFU/g). At the end of the 12 weeks storage period, EMSP maintained 25.1 %, 49.6 % and 32.6 % viable counts at room temperature, refrigeration and deep freeze condition respectively. For the lyophilized-encapsulated MSP, the mean probiotic counts of ELMSP(S) and ELMSP (SSM) were significantly (P < 0.001) higher (9.62 Log10 CFU/g) than those of ELMSP(SM) ((9.36 Log10 CFU/g) at room temperature. At refrigeration temperature, the mean probiotic counts for ELMSP (SSM. (10.1 Log10 CFU/g)) were significantly higher (P < 0.001) than ELMSP(S, (9.97 Log10 CFU/g) and ELMSP(SM, (9.86 Log10 CFU/g). Further, a 12 weeks storage study for ELMSP (SSM) showed that the microcapsules stored at refrigeration temperature (4°C) showed only 6.4 % drop in viability which was significantly lower (P < 0.001) than that of room temperature showing 15.3 % drop and deep freeze storage with 17.1 % drop in viability. It was appreciable that even at room temperature; there was only one log drop in the viability of MSP showing that it can be comfortably stored at room temperature for longer periods at field level.

Cells Total Antioxidant Capacity (TAC) and External Expression of Enzymatic Browning for the Commercially Important Penaeids Prawns Parapenaeus longirostris and Penaeus kerathurus

The enzymatic browning process, known also as melanosis, is a significant indicator of oxidative damage in commercially important shrimps and prawns. Total Antioxidant Capacity (TAC) serves as a vital measure of molecular defense against melanosis, a crucial mechanism for organisms to combat detrimental factors such as free radicals. This contribution delves into the assessment of this process for the penaeid species, Parapenaeus longirostris and Penaeus kerathurus. Samples were stored at refrigerator temperature (4 °C) for 0, 1, 2, 4, and 8 days for P. longirostris, and for 0, 2, 4, 8, and 16 days for P. kerathurus. Each day’s samples consisted of groups of ten individuals (5 males, and 5 females). TAC was determined using the CrO5 method. Results revealed an initial TAC increase followed by a gradual decrease over time. Additionally, exterior changes in both species were visually documented daily to capture the macroscopic manifestation of enzymatic browning, aligning with the molecular profile of the samples. Furthermore, Quality Index Method was conducted, where five evaluators graded the organoleptic qualities (texture, odor, color) of the prawn individuals, daily. This assessment aimed to scrutinize the external alterations of the shrimps under refrigeration conditions, revealing changes via sensory evaluation and the Quality Index Method.

Experimental study of two-phase pressure-drop in horizontal return bends with ammonia

In evaporators and condensers of refrigeration and air conditioning systems, various straight tubes are joined via U-bends. These U-bends result in higher pressure drops due to flow disturbances and centrifugal effects. Accurate prediction of pressure drops in these bends is essential for reliable design and operation. This study investigates the two-phase flow pressure-drop in horizontal U-bends with ammonia under wide range of experimental conditions. Three pipes with nominal outer diameter between 22.2, 15.9, and 9.5 mm were used, each with three bend radii (R/do ratio) between 1.2 and 2.5 in horizontal configuration. Tests were conducted at saturation temperature of +10 and -15 °C, with mass flux varying between 10 and 50 kg m−2 s−1, and vapor quality between 0.1 and 0.9. The pressure-drop increased with mass flux and vapor quality while decreased with saturation temperature, pipe diameter and R/do ratio of the bend.Large tubes exhibited a greater increase in pressure drop with rising mass flux and decreasing bend ratio compared to small tubes, which showed higher absolute values and more consistent performance across the vapor quality range at both saturation temperatures. The tube diameter had a less significant effect at high saturation temperature and high mass flux, while the bend curvature ratio predominantly influenced the pressure drop performance for large diameter tubes. One correlation from the literature predicted the data well only if the vapor quality was below 0.5. For wider range of quality, the existing models in the literature were not well-suited for predicting pressure drops in ammonia U-bends.

Repeated lyophilization: A neo-method for urine-based reference materials preparation

In urine drug testing, a cut-off value is often imposed to determine whether the sample is negative or positive. A matrix containing a reference substance helps counteract the adverse effects of the urine matrix across different laboratories to improve the consistency of final results. However, as a biological matrix, urine is prone to corruption and other problems that make it difficult to use as a reference sample. In this study, morphine, nitrazepam, lorazepam, buprenorphine, zolpidem, midazolam, diazepam, and clozapine commonly used in clinical practice were selected as target analytes, and the preparation process was further optimized to repeated lyophilization, in order to obtain more effective, stable, and accurate urine matrix reference materials (mRMs). The appropriate urine density (1.010–1.017 kg/m3) for preparing lyophilized samples was investigated through density determination. Conducting repeated lyophilizations resulted in a denser powder with reduced susceptibility to collapse and improved the quality of lyophilized urine samples. Lyophilized urine mRMs could be stored at room temperature for one month or under refrigeration conditions (4 ℃) for six months.

Design of Mixed-Metal MOF-74-MgNi for Water Adsorption-Driven Solar Thermal Energy Storage and Heat Transformation Applications.

Adsorption solar thermal energy storage and heat transformation are ecologically benign and energy-efficient technologies. Efficient adsorbents are the key to this technology. In this paper, two metal ions, Mg2+ and Ni2+, were introduced into the metal-organic framework MOF-74. The synthesis conditions were adjusted to obtain MOF-74 with a high water adsorption capacity and stability. The results show that MOF-74-MgNi-2 has the maximum water adsorption capacity. At a low moisture pressure P/P0 = 0.1, its water adsorption capacity is 0.44 g/g, 0.12 g/g, and 0.10 g/g greater than that of MOF-74-Mg and MOF-74-Ni, respectively. Its saturated water adsorption capacity at P/P0 = 0.9 is as high as 0.62 g/g, which is 1.3 times that of MOF-74-Ni and 1.1 times that of MOF-74-Mg, respectively. Its superior water adsorption capacity is explained by the combination of experiment and molecular simulation, which takes into account the pore structure and electrostatic potential energy distribution. Its thermal breakdown temperature is greater than 250 °C. Its water adsorption capacity decreases by only 9.0% in the 10th cycle. Under conventional refrigeration conditions, its refrigeration coefficient and working capacity are 0.75 and 0.43 cm3/cm3, respectively, which are greater than those of the majority of the regularly used adsorbents. In addition, it satisfies the primary technological goals of adsorption-based thermal batteries with a heat storage capacity of up to 1394 kJ/kg. The mixed-metal method is shown to be useful in the design of high-performance MOF-74 for solar thermal energy storage and heat transformation.

PSVII-20 Effect of starch content in the concentrate of finishing bison on meat nutritional composition, quality, and palatability

Abstract According to the Saskatchewan Bison Association, in the last few years producers have not been able to fill the increasing demand for bison meat. Indeed, one of the main challenges faced by the bison industry is their ability to produce a consistent product in a relatively short period of time. Hence, it is necessary to optimize the productivity and profitability of feeding bison calves while ensuring the quality of the end product. This study aimed to evaluate the effects of different starch contents in the concentrate of finishing bison on meat nutritional composition, quality, and palatability. Yearling bison bulls [n = 48; commercial Wood × Plains, 435 ± 13.4 kg body weight (BW)] were homogenously distributed into 12 pens (4 bulls/pen) based on BW, and each pen randomly assigned (n = 6) to receive either a high- [51.4% dry matter basis (DM); n = 24 bison bulls) or moderate-starch (25.8% DM; n = 24 bison bulls) concentrate, alongside free access to water and grass hay bales. After 156 d of feeding, bison bulls were slaughtered in a commercial abattoir in AB, Canada. At 3 d postmortem, color values were measured at the ribeye between the 11 and 12th ribs. Subsequently, striploins from the left carcass sides were collected, weighed, vacuum packaged, and transported under refrigeration conditions to the AAFC-Lacombe Research and Development Centre, AB, Canada. On d 6 of ageing, striploins were unpacked and weighed to measure purge losses, and pH was collected. Subsequently, six 2.5-cm thick steaks were obtained for further nutritional analyses (minerals, cholesterol, vitamin B3, protein, fat, moisture, and fatty acids), shear force, color in retail display for 4 d, and descriptive sensory and flavor profile analyses performed by trained panelists. The dietary starch content did not affect the nutritional composition as well as the pH, 3-d color values, moisture losses, and shear force value of the bison meat (P &amp;gt; 0.1). However, the high-starch concentrate increased the meat luminosity (L*) after 4 d in retail display (P &amp;lt; 0.05) and initial and overall tenderness (P &amp;lt; 0.001), and decreased the amount of perceived connective tissue (P &amp;lt; 0.001). Additionally, spongy and rubbery textures were less frequently found by trained panelists in meat from bison fed a high-starch than a moderate-starch concentrate (P &amp;lt; 0.01 and 0.05, respectively). Regarding meat flavor, the high-starch concentrate decreased salty taste (P &amp;lt; 0.05) and burnt and livery aromas (P = 0.071 and 0.069, respectively) but increased metallic flavor (P &amp;lt; 0.01) and bitter taste (P = 0.076). In conclusion, the starch content in the concentrate of finishing bison did not affect the meat nutritional value. However, some positive effects on meat color and palatability were found when feeding bison a high-starch concentrate.

Development and Usage of Refrigeration and Air Conditioning Trainer for Beginners

This study aimed to evaluate the effectiveness of the developed trainer for refrigeration, which is constructed through the specifications of the users. It focuses on the primary usage, functionality, applicability, and safety aspects of the project, as well as how it effectively assists people through innovative means. The project is tested out of 15 respondents that has knowledge regarding refrigeration and air-conditioning, enough to understand the flow of the project its material used, functions, usage and how it works. Based on the comprehensive evaluation the following key findings have emerged. Functionality Excellence, The prototype trainer demonstrates exceptional functionality, achieving an excellent rating. This indicates a high level of effectiveness in performing various task/activity in refrigeration works. Applicability of the device exhibits versatility with high ratings. Its adaptability to diverse environments underscores its broad applicability.User safety of The trainer dependability is further enhanced by the removal of potentially hazardous materials and the addition of overload protection.

Optimizing Byproduct Processing for Clean Label Foods: Avocado and MSM‐Tambaqui With a Focus on Zero Waste

ABSTRACTAgricultural byproducts, often discarded, possess significant nutritional value and technological potential. This study investigates the efficacy of ethanolic‐water extracts from avocado (Persea americana Mill.) byproducts, obtained with minimal solvent use through optimized extraction, in enhancing the stability of mechanically separated meat‐tambaqui (Colossoma macropomum) burgers, a high‐fat Amazonian fish. 2000 ppm of avocado seed and peel extract were applied in shelf‐life tests conducted under refrigeration and freezing conditions to evaluate the stability of the burgers. The results demonstrated that the bioactive compounds from avocado byproducts resulted in lower TBARS values, indicating strong antioxidant properties, reduced formation of volatile nitrogen compounds, and color maintenance than sodium erythorbate. Monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were preserved using bioactive ethanolic‐water extracts, and the protein content was improved compared to the control, enhancing nutritional quality. This study highlights the potential of using agri‐food byproducts, especially for application in highly perishable items such as fish, promoting the development of clean label products, thus supporting a more efficient and environmentally friendly food industry focusing on the circular economy.

Leading the Transition from Halogen Refrigerants to Natural Refrigerants in Indonesia (Pertamina Plaju Refinery as a Pioneer)

Abstract Climate change has become a worldwide concern, prompting Indonesia to take ambitious actions to reduce emissions and control rising temperatures. The rapid growth of the Refrigeration and Air Conditioning (RAC) industry in Indonesia has led to higher greenhouse gas emissions. To tackle these environmental challenges, Pertamina Plaju Refinery is manufacturing natural refrigerants, specifically Musicool (Propane) and Breezone (Propylene), providing sustainable replacements for R-22 and R-32. Pertamina Plaju Refinery has made several process modifications and optimizations to support the production of Musicool and Breezone in the Alkylation and Purification Units. These modifications involve optimizing operating conditions and implementing necessary infrastructure changes. In general, Pertamina’s natural refrigerants consume 20-30% less energy than halogen refrigerants while offering similar cooling capacity to R-22 and R-32. Propane and Propylene-based refrigerants have the lowest impact on global warming and are eco-friendly due to their easy degradation process. Musicool and Breezone, having an ODP of 0.0, with maximum GWP of 3.3, indicating minimal contribution to ozone depletion. Pertamina’s efforts to engage and reach potential customers on these natural refrigerants, involve collaborative efforts among various organizations, including with all District Office Plaju, South Sumatra.