Search Results (317)

In this study, we investigated the effects of air packaging, vacuum packaging and modified atmosphere packaging (CO₂/N₂: 80/20) on the purine metabolism and enzyme activities of refrigerated large yellow croakers. The results showed that modified atmosphere packaging significantly inhibited microbial growth, delayed adenosine triphosphate degradation and maintained higher IMP content (1.93 μmol/g on day 21) compared to the air packaging group (2.82 μmol/g on day 12). The total purine content increased with storage time, with hypoxanthine content increasing significantly and occupying most of the total content, which was the key factor for the elevation of purine, followed by adenine content showing a significant decreasing trend. Hypoxanthine accumulation was significantly suppressed in the modified atmosphere packaging group (2.31 μmol/g on day 18), which was much lower than that in the air packaging group (5.64 μmol/g), whereas xanthine and guanine did not show significant differences among the groups. The key enzymes xanthine oxidase and purine nucleoside phosphorylase were much less active in modified atmosphere packaging, effectively delaying the cascade reaction of inosine monophosphate → hypoxanthine → xanthine. The study confirmed that modified atmosphere packaging intervenes in purine metabolism through enzyme activity regulation, providing a theoretical basis for the preservation of low purine aquatic products. Full article

This study investigated the effect of an apple pectin coating enriched with gamma-decalactone (GDL) on the physicochemical and microbiological quality of strawberries over 9 days of refrigerated storage. Strawberries were coated with pectin solutions containing a plasticizer and emulsifier, with or without GDL, and compared to uncoated controls. The coatings were evaluated for their effects on fruit mass loss, pH, extract content (°Brix), firmness, color parameters (L*, a*, b*, C*, h*, ΔE), and microbial spoilage. The pectin coating limited changes in extract, pH, and color and slowed firmness loss. Notably, GDL-enriched coatings significantly reduced spoilage (14.29% after 9 days vs. 57.14% in the control) despite accelerating pulp softening. Extract content increased the most in the GDL group (from 9.92 to 12.00 °Brix), while mass loss reached up to 22.8%. Principal Component Analysis (PCA) confirmed coating type as a major factor differentiating sample quality over time. These findings demonstrate the potential of bioactive pectin-based coatings to enhance fruit preservation and support the development of active packaging strategies. Further studies should optimize coating composition and control the release kinetics of functional compounds. Full article

This study analyzes the aromatic profiles of kiwi-based fermented beverages, inoculated with varying proportions of milk kefir grains and incubated under different shaking rates. The experiments were designed using response surface methodology and three consecutive batch cultures were performed under each experimental condition. At the end of each fermentation, the grains were separated from the beverage and reused as the inoculum for fermenting fresh kiwi juice in the subsequent batch. Based on the results, together with the previously determined microbiological and chemical characteristics, two beverages were identified as having broader aromatic profiles, lower contents of sugars, ethanol, and acids, and high counts of lactic acid bacteria (LAB) and yeasts (>10⁶ CFU/mL). These beverages were produced under relatively low agitation rates (38 and 86 rpm) and high inoculum proportions (4.33% and 4.68% w/v) during the second and third batch cultures, respectively. Over 28 days of refrigerated storage, the pH values of both beverages remained relatively stable, and the LAB counts consistently exceeded 10⁶ CFU/mL. Yeast counts, along with the production of ethanol, glycerol, lactic acid, and acetic acid, increased slightly over time. In contrast, the concentrations of citric acid, quinic acid, total sugars, and acetic acid bacteria declined by day 28. Full article

In food processing, non-destructive and non-invasive characterization is a powerful tool for monitoring processes and controlling quality. Cheeses consist of a large variety of products whose nutritional and sensory properties depend on the source materials, cheesemaking procedures, and biochemical transformations occurring during maturation and storage. In this study, proton magnetic resonance relaxation time correlation maps (2D ¹H-NMR T₁–T₂) are used to investigate the effect of the ripening degree on Pecorino cheese and evaluate its evolution during storage in a refrigerator under vacuum-packaging conditions. NMR relaxometry has allowed for non-invasive monitoring of packaged Pecorino cheese slices, and the results were compared with those obtained with the two widely used techniques, i.e., Differential Scanning Calorimetry (DSC) and Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR). The analysis of variance and simultaneous component analysis (ASCA), separately applied to 2D ¹H-NMR T₁–T₂ correlation maps, DSC, and ATR-FTIR data, suggests that the results obtained with the NMR approach are consistent with those obtained using the two benchmark techniques. In addition, it can distinguish cheeses stored for different durations (storage time) irrespective of their original moisture content (ripening degree), and vice versa, without opening the vacuum-package, which could compromise the integrity of the samples. Full article

Almond bagasse, a by-product of almond milk production, is rich in fibre, protein, polyunsaturated fatty acids, and bioactive compounds. Its incorporation into food products provides a sustainable approach to reducing food waste while improving nutritional quality. This study explored the impact of enriching rice flour with almond bagasse powders—either hot air-dried (HAD60) or lyophilised (LYO)—at substitution levels of 5%, 10%, 15%, 20%, 25%, and 30% (w/w), to assess effects on gluten-free bread quality. The resulting flour blends were analysed for their physicochemical, techno-functional, rheological, and antioxidant properties. Gluten-free breads were then prepared using these blends and evaluated fresh and after seven days of refrigerated storage. The addition of almond bagasse powders reduced moisture and water absorption capacities, while also darkening the bread colour, particularly in HAD60, due to browning from thermal drying. The LYO powder led to softer bread by disrupting the starch structure more than HAD60. All breads hardened after storage due to starch retrogradation. The incorporation of almond bagasse powder reduced the pasting behaviour—particularly at substitution levels of ≥ 25%—as well as the viscoelastic moduli of the flour blends, due to fibre competing for water and thereby limiting starch gelatinisation. Antioxidant capacity was significantly enhanced in HAD60 breads, particularly in the crust and at higher substitution levels, due to Maillard reactions. Furthermore, antioxidant degradation over time was less pronounced in formulations with higher substitution levels, with HAD60 proving more stable than LYO. Overall, almond bagasse powder improves the antioxidant profile and shelf-life of gluten-free bread, highlighting its value as a functional and sustainable ingredient. Full article

Serra da Estrela cheese (a raw ewe’s milk) ripened for 45 days was treated at 600 MPa for 6 min (P1) and at 450 MPa for 6 (P2) and 9 min (P3) and kept in refrigerated storage for 15 months. Lactobacillus and Lactococcus viable cell numbers were reduced in 3.2–3.6 and 2.7–3.6 log cycle units, respectively. Lower reductions were verified for total aerobic mesophilic and Enterococcus viable cell numbers in cheeses treated at 450 MPa (2.4–2.5 and 1.2 log reductions, respectively). In HPP cheeses, yeasts and moulds were below the enumeration limit up to 6 months of storage, but at 15 months 3.6–4.2 log cfu/g were quantified in all cheeses, while Enterobacteriaceae were inactivated to below the quantification limit. The increment of pressure treatment caused a greater impact on the microbiota’s viability than the increase in time under pressure. During storage, minor total colour differences were determined for HPP P3 cheese surface relative to control cheeses, Ch_C, at 45 days of ripening. HPP can thus be a good process to apply after cheese manufacture, since it offers a good potential to render raw-milk cheese microbiologically safer, with minimal changes in quality. Full article

The increasing demand for reliable food preservation strategies has driven the development of active biopolymer-based films as alternatives to conventional packaging. This study evaluates Nisin/Na-EDTA-enriched alginate and gelatin films for preserving Dosidicus gigas (jumbo squid) during refrigerated storage. Films were formulated using alginate, gelatin 220/280 Bloom, and glycerol, and characterized in terms of their mechanical, optical, and biodegradation properties. Their effectiveness for the preservation of squid fillets was tested, focusing on weight loss and color stability during refrigerated storage. The incorporation of Nisin/Na-EDTA significantly modified the film’s properties: elongation at break increased from 4.95% (alginate control) to 65.13% (gelatin 280 active), while tensile strength decreased from 8.86 MPa to 0.798 MPa (alginate). Transparency was reduced by up to 2.5 times in active agent-incorporated alginate films. All films degraded within 14 days under soil exposure, with polysaccharide-based films degrading faster. In refrigerated storage, squid fillets coated with gelatin–alginate films containing Nisin showed reduced weight loss (24.05%) compared with uncoated controls (66.36%), particularly in skin-on samples. Color parameters and whiteness index were better preserved with gelatin-based coatings. These results demonstrate the potential of gelatin–alginate films with Nisin/Na-EDTA as biodegradable, active packaging to extend the shelf life of high-protein seafood. Full article

This article presents the development of a compact, high-precision, and energy-efficient temperature monitoring system designed for tracking applications where continuous and accurate thermal monitoring is essential. Built around the HY0020 System-on-Chip (SoC), the system integrates two bandgap-based temperature sensors—one internal to the SoC and one external (Si7020-A20)—mounted on a custom PCB and powered by a coin cell battery. A distinctive feature of the system is its support for real-time parameterization of the internal sensor, which enables advanced capabilities such as thermal profiling, cross-validation, and onboard diagnostics. The system was evaluated under both room temperature and refrigeration conditions, demonstrating high accuracy with the internal sensor showing an average error of 0.041 °C and −0.36 °C, respectively, and absolute errors below ±0.5 °C. With an average current draw of just 0.01727 mA, the system achieves an estimated autonomy of 6.6 years on a 1000 mAh battery. Data are transmitted via Bluetooth Low Energy (BLE) to a Raspberry Pi 4 gateway and forwarded to an IoT cloud platform for remote access and analysis. With a total cost of approximately EUR 20 and built entirely from commercially available components, this system offers a scalable and cost-effective solution for a wide range of temperature-sensitive applications. Its combination of precision, long-term autonomy, and advanced diagnostic capabilities make it suitable for deployment in diverse fields such as supply chain monitoring, environmental sensing, biomedical storage, and smart infrastructure—where reliable, low-maintenance thermal tracking is essential. Full article

Background: Bronchoalveolar lavage fluid (BALF) analysis is essential for the accurate diagnosis and management of interstitial lung diseases (ILDs). Despite established guidelines, variability in sample handling may affect diagnostic accuracy. This study aimed to evaluate how different storage conditions impact BALF cell counts and differentials to guide optimal sample handling practices. Methods: Forty patients who underwent BAL at Chiba University Hospital from June to December 2024 were included. BALF samples were allocated into five groups based on processing conditions: immediate analysis within 1 h, storage at either at 4 °C or room temperature (RT) for 6 h, or storage at 4 °C or RT for 24 h. Total cell counts (TCC) and differential counts were measured and compared among conditions. Results: TCC remained stable over 24 h at both 4 °C (p = 0.86) and RT (p = 0.90). Similarly, the percentages of eosinophils, lymphocytes, and macrophages did not significantly change at either temperature (all p > 0.05). Notably, neutrophil percentages showed a significant decline over time under both storage conditions—at 4 °C (p = 0.02) and at room temperature (p < 0.01). Post hoc tests revealed a notable decreasing trend at 6 h and significant reductions by 24 h at 4 °C (p = 0.09 and p = 0.02, respectively), and significant decreases at both 6 and 24 h at RT (p = 0.01, <0.01). Conclusions: Among the various cell types in BALF, neutrophil proportions are particularly susceptible to storage conditions, showing a significant decline over time—especially at room temperature—while other cell types remain stable for up to 24 h. Therefore, prompt processing or appropriate refrigeration of BALF is essential to ensure reliable cytological analysis and accurate clinical interpretation. Full article

This study evaluated the effects of selected polysaccharide edible coatings (apple pectin and sodium alginate) on the quality characteristics of fresh-cut beetroot. The changes in texture (hardness), optical parameters such as colour and Hue angle, polyphenols, flavonoids, and red and yellow colourants during 4 weeks of refrigerated storage, as well as changes in microstructure, were examined. Self-standing coatings have also been prepared and characterised by continuous structure without pores, cracks, and high lightness. The obtained results for hardness showed reduced values during storage. Colour parameters (L*, a*, and b*) and Hue angle remained mostly consistent, indicating the preservation of the desired colour, though slight changes were noted during storage. Lightness (parameter L*) increased over time, suggesting changes in the beetroot surface. However, these changes were less pronounced in samples covered with coatings. The use of polysaccharide coatings and storage time positively impacted flavonoids in fresh-cut beetroots, except after 28 days when the lowest values for both parameters were observed. It can also be noted that the polyphenol content in coated samples decreased at a slower rate. Moreover, there was a significant decrease in the content of red and yellow colourants for both control and coated samples. However, greater changes were noted for samples treated with coatings. Scanning electron microscopy used at 0 and 28 days showed lower pores in beetroot tissue as a result of applied polysaccharide coatings, and refrigerated storage negatively affected the minimally processed beetroot surface. Nevertheless, minimally processed beetroots obtained with the treatment of polysaccharide coatings as mild technology showed modifications to the quality characteristics, which can find practical use in reducing the waste of fresh-cut vegetables during storage. Full article

Mead is a fermented alcoholic beverage obtained by diluting honey in water and adding yeast. However, the addition of fruit to this beverage gives rise to melomel. In this study we are proposing an interesting novelty which consists of developing cupuaçu (Theobroma grandiflorum) melomel by fermenting Saccharomyces cerevisiae var. boulardii. The aim of this study was to develop cupuaçu (Theobroma grandiflorum) melomel produced by S. boulardii and to evaluate its physicochemical and microbiological characteristics after refrigerated storage at 4 °C. To do this, a central composite design (CCD) was employed, with two independent variables, i.e., the initial soluble solids content of the honey must (°Brix) and the concentration of the cupuaçu pulp (%). A standardized amount of 1 g/L of S. boulardii yeast was used at a temperature of 25 °C and a fermentation time of 30 days. Using the results of the central composite design (CCD), the best conditions for producing the beverage were defined according to the objectives of the study. Thus, the experimental comparison was carried out under the conditions of 25 °Brix of initial soluble solids in the honey must, 10% cupuaçu pulp, and 10 days of fermentation at 25 °C. The cupuaçu melomel exhibited a cell viability of the probiotic yeast S. boulardii above 10⁷ log CFU/mL, with an alcohol content of 8.22% (v/v), a pH of 3.43, a total acidity of 54.8 of (mEq/L), and soluble solids of 12.42°Brix. In addition, the beverage was subjected to simulated gastric and intestinal juices in vitro to evaluate the survival of the microorganisms under these conditions, and a concentration of 10⁶ log CFU/mL of S. boulardii was obtained. In this way, it was possible to produce a probiotic fermented alcoholic beverage made from honey and cupuaçu. Full article

The extension of shelf-life and enhancement of the safety and quality of fresh-cut ready-to-eat vegetables is an ongoing public health concern. The present study investigated the efficacy of cold atmospheric plasma (CAP) treatment for the decontamination of fresh-cut carrots inoculated with Escherichia coli. An atmospheric plasma jet system operating at 1 kVA was utilized for treatment with varying plasma jet nozzle to sample distances (10–40 mm), exposure times (10–60 s) and either argon or dry air at 3 bar as working gases. It was demonstrated that both working gases achieved more than 4 log reductions in E. coli within 60 s of treatment while maintaining carrot surface temperatures below 50 °C. During 3-week storage at 4 °C, the immediate effects of plasma treatment on quality parameters were found to be minimal, with no significant changes observed in color (ΔE < 3.0) parameters, β-carotene content, ascorbic acid levels, total phenolic content (TPC), or total antioxidant activity (TAA) following either treatment. Additionally, plasma-treated carrots retained their firmness, showing no significant texture loss, whereas untreated controls experienced a firmness decline of approximately 9% by the end of storage. Notably, TPC increased by up to 41%, and TAA increased significantly (p < 0.05) in plasma-treated samples during storage, especially in dry air plasma-treated carrots. These results demonstrated that CAP treatment can be successfully applied for rapid inactivation of E. coli on fresh-cut carrot surfaces while preserving original quality characteristics during refrigerated storage, offering potential as non-thermal preservation technology for fresh produce. Full article

Microencapsulated phase-change materials (MPCMs) with excellent thermal properties for low-temperature cold storage were developed in this study. Using 1-decanol as the core and methyl methacrylate as the shell precursor, the effects of emulsifier type and ultrasonic emulsification conditions were investigated. Styrene-maleic anhydride copolymer served effectively as a protective colloid emulsifier, producing MPCMs with high enthalpy and a well-defined, uniform microstructure. Under optimal conditions of 5 wt% emulsifier content relative to the oil phase, an ultrasonic power of 375 W, and an emulsification time of 12 min, the MPCMs exhibited a phase-change enthalpy of 126.7 kJ/kg. To further improve the thermal properties, a binary eutectic mixture was prepared by combining 1-decanol and 1-tetradecane at an optimal molar ratio (51.1:48.9). This binary-core MPCM showed a higher storage enthalpy (144.3 kJ/kg), with an increase of 13.9% compared to the single-core material (1-decanol). It also exhibited improved microstructural uniformity due to the stabilizing role of 1-tetradecane. These optimized MPCMs demonstrate phase-transition temperatures particularly suitable for low-temperature thermal storage, providing a practical and innovative technical solution for cold-chain logistics and vaccine refrigeration applications. Full article

Background/Objectives: The present study aimed to investigate the effects of frozen (−18 °C) and refrigerated (4 °C) storage conditions on several beef bottom round quality parameters. Methods: Fresh beef bottom round samples were stored under both frozen (−18 °C) and refrigerated (4 °C) conditions. For frozen samples, the pH, color, cooking loss, thawing loss, centrifugal loss, drip loss, moisture content, shear force, TBARS and TPA were measured at 0, 30 and 60 days. For refrigerated samples, the pH and color were analyzed at 0, 1, 3, 5 and 7 days, and the differential metabolites were also identified based on the VOCs analysis combined with multivariate statistical analysis. Results: The surface color (L*, a*, and b*) of the beef bottom round became darker during both the frozen and refrigerated periods of prolonged storage. The samples’ pH significantly declined (p < 0.05) during the frozen storage but alternated (initially reduced and then increased) under refrigerated conditions. Additionally, the frozen treatment led to a significant change (p < 0.05) in the texture profile. The thiobarbituric acid reactive substance (TBAR) values, shear force, cooking loss, thawing loss, centrifugal loss, and drip loss increased significantly with an extended frozen storage time, while the moisture content was significantly lower (p < 0.05). Moreover, nine volatile organic compounds (VOCs) were identified as potential determinants of beef bottom quality during refrigerated storage. Conclusions: The findings can contribute to a deeper understanding of quality variations during frozen storage and refrigerated storage, and provide new thoughts to improve preservation and storage strategies for the beef bottom round. Full article

A unique isotonic sports drink (ISD) was created in this study using a pilot-scale short-wave ultraviolet light (UV-C, 892 mJ/cm², 20 °C) assisted by mild heat (UV-C/H, 534 mJ/cm², 50 °C), which was followed by the addition of yerba mate (Ilex paraguariensis) extract (YME). Consumer perception and microbiological and physicochemical stability during refrigerated storage (4 °C/23 d) were assessed for the ISD. Alicyclobacillus acidoterrestris (AA) spores and cocktails of yeasts and Escherichia coli were considerably inactivated by UV-C/H. The TEM and SEM micrographs showed that AA evidenced sustained severe structural damage. Furthermore, UV-C/H completely inactivated the native microbiota, while YME incorporation increased the initial aerobic mesophilic and mold-and-yeast populations by 0.48 and 0.70 log cycles, remaining stable during storage. YME addition enhanced total polyphenols, flavonoids and antioxidant activity by 2.7–3.7, 16.5–16.7 and 6.6–24.0 times compared to the untreated ISD and ISD-UVC/H samples. Except for sedimentation and turbidity, the other physical characteristics mostly did not change (going from 1494 ± 382 to 2151 ± 106 NTU). The initial 5-HMF value in the ISD was raised by UV-C/H treatment and YME addition. Notwithstanding, it stayed below the allowed threshold throughout storage. ISD-UVC/H+YME had a high overall acceptability score; 60% of panelists gave the drink a score of seven or higher. Additionally, the herbal taste of YME was well liked, and its bitterness was perceived as mild. These findings suggest that including YME and the UV-C/H treatment can produce an ISD of superior quality with distinct sensory attributes. Full article