Search Results (361)

Increasing consumer demand for healthier and clean-label meat products, together with health concerns over synthetic antioxidants, has driven interest in natural alternatives. In this context, tannin-rich extracts were evaluated as functional ingredients to improve the quality and shelf life of beef patties. The effect of two different tannin-rich extracts, each tested at three different concentrations (0.005%, 0.02%, and 0.04% w/w), was investigated in beef patties. Obtained results were compared with a commercial rosemary extract (0.2% w/w) and an untreated control. Natural antioxidant supplementation significantly reduced lipid oxidation during refrigerated storage, limiting malondialdehyde (MDA) formation. At the end of the 7-day storage period, the control sample exhibited the highest thiobarbituric acid reactive substance (TBARS) value of 2.99 ± 0.01 mg MDA/kg, whereas treated samples showed markedly reduced oxidation (0.34–0.97 mg MDA/kg), with tannin-rich extracts presenting greater antioxidant efficacy with respect to rosemary extract (p < 0.001). The natural compounds also effectively inhibited hexanal formation and delayed the accumulation of 1-octen-3-ol compared with the control (p < 0.001). Moreover, all extracts enhanced meat redness, as indicated by higher CIELAB a* values, while no significant effects (p > 0.05) were observed on texture, microbial growth, or overall sensory acceptance. These results highlight tannin-rich extracts as promising natural antioxidants for improving oxidative stability and extending the shelf life of beef patties. Full article

Background/Objectives: MDMA and MDA are among the stimulant drugs most frequently encountered in forensic casework, and oral fluid represents a practical biological matrix for their detection. However, liquid oral fluid requires refrigeration, is susceptible to degradation, and can be logistically demanding for routine laboratories. Dried Oral Fluid Spots (DOFS) offer a low-cost and stable alternative. This study aimed to develop and validate a DOFS-based analytical workflow for quantifying MDMA and MDA using liquid chromatography and a diode-array detector. Methods: Watercolor paper was selected as the substrate and pretreated with diluted nitric acid to improve analyte desorption. DOFS were prepared using 150 µL of pooled oral fluid, dried for 4 h, and extracted with methanol. Chromatographic separation was performed on a phenyl column using aqueous TFA and acetonitrile mobile phase. Method validation followed the ICH M10 criteria. Results: The method showed linear responses between 12.5 and 5000 ng mL⁻¹, with LOD and LLOQ of 6 and 12 ng mL⁻¹ for both analytes, respectively. Precision and accuracy met acceptance criteria across all QC levels. Recoveries ranged from 84% to98%. DOFS samples demonstrated adequate stability under multiple storage and handling conditions. Conclusions: The optimized DOFS–LC–DAD workflow offers a robust, low-cost, and flexible approach for the analysis of MDMA and MDA in oral fluid for laboratory-based or semi-controlled collection environments. Its compatibility with both LC- and GC-based detectors enhances applicability in diverse forensic laboratory settings. Full article

The global food industry is undergoing a major shift driven by increasing consumer demand for clean-label and naturally preserved foods. Fresh pasta is highly vulnerable to fungal damage because of its high water activity (a_w > 0.85), typically ranging between 0.92 and 0.97, moderate to near-neutral pH (around 5.0–7.0), and nutrient-rich composition, all of which create favorable conditions for fungal growth during refrigeration, mainly by genera such as Penicillium and Aspergillus. Fungal contamination results in significant economic losses due to reduced product quality and poses potential health risks associated with mycotoxin production. Although conventional chemical preservatives are relatively effective in preventing spoilage, their use conflicts with clean-label trends and faces growing regulatory and consumer scrutiny. In this context, antifungal lactic acid bacteria (LAB) have emerged as a promising natural alternative for biopreservation. Several LAB strains, particularly those isolated from cereal-based environments (e.g., Lactobacillus plantarum and L. amylovorus), produce a broad spectrum of antifungal metabolites, including organic acids, phenylalanine-derived acids, cyclic dipeptides, and volatile compounds. These metabolites act synergistically to inhibit fungal growth through multiple mechanisms, such as cytoplasmic acidification, energy depletion, and membrane disruption. However, the application of LAB in fresh pasta production requires overcoming several challenges, including the scale-up from laboratory to industrial processes, the maintenance of metabolic activity within the complex pasta matrix, and the preservation of desirable sensory attributes. Furthermore, regulatory approval (GRAS/QPS status), economic feasibility, and effective consumer communication are crucial for successful commercial implementation. This review analyzes studies published over the past decade on fresh pasta spoilage and the antifungal activity of lactic acid bacteria (LAB), highlighting the progressive refinement of LAB-based biopreservation strategies. The literature demonstrates a transition from early descriptive studies to recent research focused on strain-specific mechanisms and technological integration. Overall, LAB-mediated biopreservation emerges as a sustainable, clean-label approach for extending the shelf life and safety of fresh pasta, with future developments relying on targeted strain selection and synergistic preservation strategies. Full article

The dairy industry requires effective non-thermal processing strategies capable of ensuring microbial safety while preserving the nutritional and bioactive quality of milk. This study describes a novel milk decontamination approach based on selective ionic removal by dialysis, resulting in a controlled reduction in ionic strength. Milk deionization significantly reduced the microbial load in raw bovine milk to levels comparable to those achieved by conventional thermal pasteurization, while largely preserving its physicochemical composition. Ionic depletion enhanced the antimicrobial effectiveness of endogenous milk components; this effect was abolished when native salt concentrations were maintained, highlighting the key role of ionic modulation in microbial control. Major milk constituents, including proteins, fat, and solids-not-fat, were not substantially affected by deionization, whereas low-molecular-weight solutes such as lactose and urea were partially removed. Deionized milk also exhibited improved stability during refrigerated storage, as evidenced by delayed acidification compared with raw and pasteurized milk. Overall, these results demonstrate that milk deionization represents a feasible proof-of-concept non-thermal alternative to pasteurization based on ionic modulation, with potential applications in dairy processing and human milk preservation, where maintenance of bioactive components is particularly desirable. Full article

The increasing demand for sustainable, nutrient-dense plant-based foods has intensified interest in functional ingredients that enhance nutritional quality. This study developed plant-based patties by partially replacing texturized pea protein with chia seed powder (CSP; Salvia hispanica L.) and evaluated their quality during 20 days of refrigerated storage (4 °C) under nitrogen-flushed packaging. Six formulations (F1–F6) containing 0–25% CSP were evaluated for physicochemical properties, lipid oxidation, and nutritional composition. Based on an optimal balance of texture, cooking yield, antioxidant capacity, and nutritional enhancement, the formulation containing 20% CSP was selected for further analyses. Proximate analysis revealed significant increases in protein (18–21%), fat (9–12%), and ash (2–3%) contents, accompanied by a slight reduction in moisture. All formulations maintained a stable pH throughout storage. Lipid oxidation increased gradually from 0.10–0.17 to 0.89–1.10 mg MDA/kg over 20 days but remained within acceptable limits. Fatty acid profiling indicated enhanced polyunsaturated fatty acids, particularly omega-3 and omega-6. Amino acid analysis showed elevated levels of key amino acids, including glutamic acid, aspartic acid, arginine, leucine, and lysine. Overall, patties containing 20% CSP exhibited improved nutritional quality and satisfactory oxidative stability, highlighting CSP as a promising functional ingredient for plant-based meat alternatives. Full article

Polyurethane (PU) is widely recognized for its efficient oil sorption properties. However, this capacity is highly dependent on its intrinsic chemical composition and morphological structure, which can be altered by mechanical or chemical treatments commonly applied before using it as a sorbent. In this study, we present a comprehensive investigation of the oil sorption behavior of both soft and rigid PU foams, and their blade-milled ground (BMG) counterparts obtained by mechanical treatment of several recycled PU-based products, including seats, mattresses, side panels of cars, packaging components, and insulating panels of refrigerators and freezers. We found that blade milling the soft PU foams leads to a significant reduction in oil sorption capacity proportional to the extent of grinding. Pristine soft PU foams and BMG-PUs with intermediate particle size (−250 μm–1 mm) exhibited the highest oil uptake (20–30 g/g), whereas the finest fraction (5 μm–250 μm) showed a lower capacity (3–7 g/g). In contrast, rigid PU foams showed consistently low oil sorption (~5 g/g), with negligible differences between the original and ground materials. At the macroscopic level, optical and morphological analyses revealed the collapse of the 3D porous network and a reduction in surface area. On the microscopic scale, spectroscopic, structural, and thermal analyses confirmed phase separation and rearrangement of hard and soft segmented domains within the polymer matrix, suggesting a different mechanism for oil sorption in BMG-PU. Despite reduced performance compared to pristine foams, BMG-PU powders, especially those with intermediate dimensions and originating from soft PU foams, present a viable, low-cost, and sustainable alternative for oil sorption applications, including oil spill remediation, while offering an effective strategy for effective recycling of PU foam wastes. Full article

Ground meat is highly perishable and has a short shelf life due to microbial contamination with food spoilage bacteria along with foodborne pathogens, which increases the risk of food poisoning. Controlling microbial growth by using chemical or synthetic food additives or preservatives is of great health concern. Natural, plant-derived antimicrobial food additives are safer alternatives. Therefore, the main objective of this study was to evaluate the antimicrobial efficacy of different forms and concentrations of clove against food spoilage and foodborne pathogens and to determine their ability to enhance sensory quality and extend the shelf life of buffalo meatballs during refrigerated storage. Clove oil (0.25, 0.50, and 1.0 g/kg), clove extract (0.5, 1.0, and 1.5 g/kg), and clove powder (2.5, 5.0, and 7.5 g/kg) were assessed against aerobic plate counts (APCs), psychotropic counts (PCs), and foodborne pathogens such as Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Escherichia coli O157:H7, artificially inoculated in buffalo meatballs. Clove oil, clove extract, and clove powder treatments showed a significant (p < 0.01) reduction in the counts of S. aureus, S. enterica serovar Typhimurium, and E. coli O157:H7 compared to control samples. Among all tested forms and concentrations of clove, clove oil at 1.0 g/kg proved to be the most effective against the tested pathogens, as by the end of storage (day 12), it achieved 5.3 and 5.56 log reductions in S. aureus and S. enterica serovar Typhimurium, respectively, along with complete reduction in E. coli O157:H7, followed by clove extract at 1.5 g/kg, which produced 4.2, 4.92, and 7.01 log reductions in the corresponding three foodborne pathogens. The results showed that different concentrations of clove oil and extract treatments applied effectively improved the sensory attributes (flavor, tenderness, juiciness, and overall acceptability) of buffalo meatballs, while the sensory properties of clove powder were considered unacceptable, as it alters the taste and smell of meat. The ground buffalo meat treated with different concentrations of clove oil, clove extract, and clove powder significantly reduced the growth of APCs and PCs during refrigerated storage, resulting in 1.5 to 2.6 log reductions with a prolonged shelf life ranging from 9 to 12 days. Overall effects on shelf life and meat quality showed that all clove forms significantly slowed microbial growth and extended the shelf life of buffalo meatballs to 9–12 days, in contrast to 6 days or less for the control. The findings indicate that clove oil and clove extract are promising natural preservatives capable of improving microbial safety, maintaining sensory attributes, and enhancing the overall quality of buffalo meatballs during refrigerated storage. Full article

The International Agreement on the Carriage of Perishable Foodstuffs and on the Special Equipment to Be Used for Such Carriage (usually known as ATP Treaty) defines a standardized isothermal test for qualifying refrigerated containers, but its current protocol is lengthy, costly and lacks scientific justification. This paper presents a combined theoretical and experimental study aimed at optimizing this procedure. First, a heat-transfer framework based on transient conduction and thermal diffusivity is developed to estimate stabilization times using dimensionless criteria. Then, extensive experimental tests on ATP containers validate these predictions and reveal additional phenomena such as air leakage and chimney effects. Based on these findings, a revised protocol is proposed that reduces the test duration from more than 18 h to approximately 2 h while preserving the thermal stabilization conditions required by ATP. Experimental results show that the uncertainty in the determination of the global heat-transfer coefficient K is reduced from about 2–$2.3\%$ in the classical ATP procedure to roughly $0.7$–$1.0\%$ with the new protocol. In addition, the method suppresses secondary physical effects—such as chimney-driven air leakage and latent-heat losses due to water evaporation—thus improving the physical representativeness of the measured K value. The proposed accelerated protocol offers a scientifically grounded, cost-effective alternative for future ATP standards. Full article

Bee pollen is a food with high nutritional value and important functional properties. It is usually consumed as dried pollen, due to the need for a preservation process that controls the high microbiological load of the fresh product. Unfortunately, dry pollen is unattractive to consumers. In this sense, the use of ozone may be an alternative for preserving fresh pollen, since it reduces the microbiological load, allowing for other preservation methods, including refrigeration, and it preserves the original texture and flavors of the product, making it more palatable. However, it is important to know how ozone can affect some of the bioactive properties of pollen, such as phenolic compounds (PC), or the antioxidant properties of this food. The aim of this research was to assess the effect of ozone treatment on the above-mentioned properties and to compare it with the conventional drying treatment. For this purpose, 19 samples of fresh bee pollen were collected. From each sample, five subsamples were obtained, two of which were treated with ozone for 1 h and 2 h (O1 and O2, respectively), two were dried for 4 h and 8 h (D4 and D8, respectively), and the fifth subsample remained as the untreated control (C). The results showed that ozone treatments did not have a negative effect on phenolic content (PC) or on antioxidant activity (AA). This would be positive for the use of this decontamination method. In contrast, traditional drying treatments significantly reduced total PC while increasing AA compared to C, O1, and O2. A low correlation was found between these variables in the studied samples. Full article

The study evaluated the potential of Thymus mastichina, Lavandula luisiery, and Origanum virens hydrolates—essential oil-rich species found in the Dehesa ecosystem—as natural agents for pork preservation through marination. Hydrolates, the main by-products of essential oil distillation, were characterized by their volatile composition, total phenolic content, antioxidant capacity, and antimicrobial activity against Escherichia coli and Listeria innocua. Pork fillets were marinated (24 h) with increasing hydrolate concentrations (1:1, 1:1.5, 1:2 w/w) and then stored for eight days under refrigeration to assess microbial growth, oxidation, and color changes. All hydrolates exhibited similar antimicrobial effects, though Origanum showed the highest phenolic content and antioxidant activity. Marination had limited antimicrobial impact. Marination with Origanum and Thymus provided significant protection against lipid oxidation during storage, while Lavandula displayed limited or even pro-oxidative behavior at certain doses. Marination did not affect carbonyl formation although it caused slight changes in instrumental color. Overall, the study highlights the potential of Lavandula, Thymus, and Origanum hydrolates as sustainable alternatives to synthetic antioxidants in meat products, emphasizing their antioxidant—rather than antimicrobial—effect. Full article

This study proposes a novel multi-porous heat exchanger (MPHEX) as a passive, sustainable alternative to variable refrigerant flow (VRF) air conditioning systems, addressing the growing environmental burden of cooling demand. Through high-fidelity Lattice Boltzmann Method simulations of coupled heat and fluid transport, the MPHEX design is optimized to minimize exergy destruction. A case study for Tunisian conditions demonstrates that permeability optimization, when combined with solar-assisted preheating, reduces total exergy destruction by over 60% and increases the coefficient of performance (COP) by up to 20%, all while eliminating active mechanical regulation. The numerical results confirm strong experimental feasibility, positioning the MPHEX as a scalable, low-energy, and low-maintenance cooling solution for sun-rich regions. Full article

The present paper investigates the generation of the alternating almost zero and strong homogeneous magnetic fields for rotary magnetic refrigeration. In order to achieve an alternating magnetic field with eight regions, a soft magnetic rod is inserted in the bore. Four high-flux-density regions (FDRs) for magnetization and four low-flux-density regions for demagnetization of magnetocaloric materials are obtained by the proposed design. The design procedure for the four-pole structure and its implementation using 3D finite-element simulation are presented. To meet the predefined requirements, some magnet segments are replaced with high-permeability soft magnetic material. The proposed magnetic design for the rotary refrigerator allows good field distribution in the air gap, a high ratio of high-field-to-permanent-magnet volume, a minimized low-field volume, reduced magnet usage to the permanent-magnet volume, reduction of the amount of magnet material used, and increased flux density between the low- and high-field regions. Full article

C₆F₁₂O has been recognized as an environmentally friendly substitute applied in the fire protection, insulation equipment, and refrigeration industry. The stability and catalytic decomposition characteristics of C₆F₁₂O in the presence of metals are crucial for evaluating the applicability of such alternatives across different scenarios and recycling treatment. In this study, the adsorption and decomposition mechanisms of C₆F₁₂O on Cu (1 0 0), Cu (1 1 0), and Cu (1 1 1) surfaces have been investigated based on the density functional theory (DFT). The adsorption structures and energies of C₆F₁₂O and its key dissociation products are investigated to obtain the most stable adsorption configurations. Additionally, the projected density of states (PDOS) and electron density difference calculations are performed to explore the electronic properties of the adsorption systems. Four major dissociation reactions involving the C-C bond breakage of C₆F₁₂O that occurred on Cu surfaces are examined individually, with comparisons made to the corresponding homolytic reactions of free C₆F₁₂O. The results indicate that Cu surfaces exhibit a promising catalytic effect for C₆F₁₂O decomposition, which depends on both the kind of surfaces and the reaction pathway. Furthermore, most decomposition pathways of C₆F₁₂O on Cu surfaces are exothermic and C₆F₁₂O tends to decompose into C₅F₉O and CF₃ under the Cu catalytic effect. Full article

In the naval sector, hydrofluorocarbons (HFCs) are the primary refrigerants in use. To face global environmental challenges, international treaties have established stringent regulations aimed at transitioning towards more sustainable alternatives. Natural refrigerants are proposed as valid solutions, with a particular focus on carbon dioxide (R744) due to its very low direct environmental impact and high safety. This paper evaluates the potential of using R744 as a refrigerant for refrigeration systems onboard cruise ships; based on the R744 innovative solutions currently proposed in the literature for cruise ship applications, the aim is to assess whether the transition to R744 would provide advantages in terms of energy performance and total environmental impact compared with conventional systems employing HFCs. The analysis includes a description of the conventional provision and air conditioning systems mounted onboard and innovative technologies utilizing R744 as a refrigerant, proposed in the literature. These systems are numerically analyzed and compared. The numerical results show that the exclusive use of R744 in onboard systems would significantly reduce the direct environmental impact compared with the current HFCs-based configurations. However, when considering the total impact, further technological advancements in R744 systems are required to achieve a reduction in indirect emissions as well. While progressing toward full R744 adoption, some promising pathways are proposed to enhance current system efficiency. Full article

Thermoelectric generators are a great alternative for waste heat energy harvesting in several technological fields. Vapor compression refrigeration systems present great potential for waste heat energy harvesting as they dissipate heat in a condenser/gas cooler from the refrigerant to the ambient. This heat can be harvested by utilizing a thermoelectric generator. The objective of this study is to evaluate the energy harvesting potential of thermoelectric generators in transcritical vapor compression cycles and their effect on cycle performance. A computational model is used to simulate a transcritical carbon dioxide refrigeration cycle with the inclusion of a thermoelectric generator between the compressor and the gas cooler. The energy harvested by the generator is calculated, and the effect on the vapor compression system is quantified. The results show that by including the thermoelectric generator, two positive effects are obtained: the electrical energy generated by the thermoelectric system positively enhances the efficiency of the cycle, and the heat extracted in the generator leaves room for further cooling in the gas cooler, producing an increase in cooling capacity that also enhances efficiency. The results show an increase in the coefficient of performance that ranges between 3.74 and 12.14% for different working conditions. Full article