Search Results (247)

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

Wildfires can significantly alter soil physicochemical conditions and microbial communities in forest ecosystems. This study aimed to characterize the culturable soil fungal community and evaluate biological activity in Banco Totumo Bijibana, a protected dry tropical forest in Atlántico, Colombia, affected by a wildfire in 2014. Twenty soil samples were collected for microbiological (10 cm depth) and physicochemical (30 cm) analysis. Basal respiration was measured using Stotzky’s method, nitrogen mineralization via Rawls’ method, and fungal diversity through culture-based identification and colony-forming unit (CFU) counts. Diversity was assessed using Simpson, Shannon–Weaver, and ACE indices. The soils presented low organic matter (0.70%) and nitrogen content (0.035%), with reduced biological activity as indicated by basal respiration (0.12 kg C ha⁻¹ d⁻¹) and mineralized nitrogen (5.61 kg ha⁻¹). Four fungal morphotypes, likely from the genus Aspergillus, were identified. Simpson index indicated moderate dominance, while Shannon–Weaver values reflected low diversity. Correlation analysis showed Aspergillus-3 was positively associated with moisture, whereas Aspergillus-4 correlated negatively with pH and sand content. The species accumulation curve reached an asymptote, suggesting an adequate sampling effort. Although no control site was included, the findings provide a baseline characterization of post-fire soil microbial structure and function in a dry tropical ecosystem. Full article

Following hygiene standards in milk production is essential for making high-quality sour cream, especially when using traditional methods that rely on raw milk. The aim of this study was to determine the physicochemical, microbiological, and sensory quality of artisanal sour cream samples collected from major marketplaces in the wider Zagreb area. On average, the samples contained 27.99% milk fat, 3.30% protein, 34.29% dry matter, 6.51% fat-free dry matter and 3.00% lactose, with considerable variability observed across all components. Microbiological analysis revealed the presence of Staphylococcus aureus in 35.30% of the samples, Enterobacteriaceae in 76.47%, Escherichia coli in 94.11%, Bacillus spp. in 23.53%, and yeasts in 100% of the samples. Listeria monocytogenes and Salmonella spp. were not detected. The sensory analysis of the textural properties showed significant variability in firmness, adhesiveness, viscosity, creaminess, and fizziness. Samples with higher milk fat and dry matter content were rated better for creaminess, viscosity and mouth firmness. Flavour assessments, particularly for cream and diacetyl notes, also varied widely among samples. These findings highlight the complexity of sour cream’s sensory attributes and the significant influence of ingredient composition and processing techniques on appearance, aroma, texture, taste, and flavour. Principal component analysis (PCA) with Varimax rotation simplified the data structure and identified key dimensions of quality variation. Principal component analysis (PCA) revealed that the first principal component (PC1) effectively discriminated the cream samples based on sensory attractiveness and indicators of spoilage and highlighted the association between off-flavour and microbial contamination with inferior characteristics. The second principal component (PC2) captured the differences in physicochemical characteristics and showed a gradient from richer, creamier samples with higher fat content to those with lower acidity and higher freshness. Full article

This study aimed to develop a fermented mango-based beverage using Lactiplantibacillus plantarum strains Lp6 and Lp32, focusing on enhancing its functional properties, ensuring microbiological safety, improving nutritional value, and achieving sensory acceptability. A central composite design (CCD) was employed to assess the effects of two factors (fermentation time and inoculum concentration) on several response variables: viable cell concentration (CC), total phenolic compounds (TPCs), total flavonoid compounds (TFCs), and concentrations of L-lactic acid and D-lactic acid. The optimized formulation was achieved using L. plantarum Lp6, with an inoculum concentration of 9.89 Log (7.76 × 10⁹) CFU/mL and a fermentation time of 20.47 h. Under these conditions, the beverage reached the highest values for CC, TPC, TF, and L-lactic acid while minimizing the production of D-lactic acid. Following optimization, the fermented beverage underwent further characterization, including physicochemical analysis, microbiological evaluation, proximate composition analysis, and sensory evaluation. The final product exhibited a viable cell count of 13.01 Log (10.23 × 10¹²) CFU/mL, demonstrated functional potential, complied with microbiological safety standards, and showed adequate nutritional content. Sensory analysis revealed high consumer acceptability, attributed to its distinctive mango aroma and flavor. These findings highlight the potential of this fermented mango-based beverage as a novel functional food with promising market appeal. Full article

The growing demand for the production of food has led to the development of new analytical techniques in the food industry, enabling innovative strategies to streamline food production and ensure its physicochemical and microbiological quality. In this work, a smart sensor was developed using the electrical impedance spectroscopy (EIS) technique. The system is based on discrete Fourier transform (DFT) and incorporates a Howland current source. The experimental results showed that the sensor was able to detect the moisture content in potatoes (Solanum tuberosum L.). Favorable responses were obtained by exciting the system with two frequency intervals: 0–100 Hz and 500–5000 Hz. An exhaustive analysis of the frequency response was performed to identify the most linear behavior in the moisture measurement, with an R-squared of 0.786 and signals in intervals from 500 to 5000 Hz. Moreover, the linearity remained stable across most frequencies, resulting in consistent measurements, even with the implementation of low-cost components. Full article

Microbiological safety and quality consistency are critical challenges in the production of traditional Indian fried snacks, particularly in small-scale food enterprises. With growing export demand, maintaining strict quality control measures is essential. This study assessed the microbiological and physicochemical quality of five traditional Indian fried snacks—Kerala Murukku, Kerala Mixture, Banana Chips, Tapioca Chips, and Achappam—produced in a Food Safety Management System (FSMS)-certified facility over a four-year period (2020–2023). Products were evaluated for moisture, pH, salt content, acid value, and Total Plate Count (TPC). The number of ingredients for each product was recorded from standardized product formulation documents. TPC levels remained within acceptable limits (below 50,000 CFU/g) across all products. Among them, Kerala Mixture consistently showed the highest microbial counts (up to 4.61 log CFU/g) and Achappam the lowest, with no detectable variance (1.00 log CFU/g). Statistically significant year-wise differences (p < 0.05) were observed in all quality parameters. Kerala Mixture showed variation in salt and microbial load; Kerala Murukku varied in moisture, pH, and salt; while Tapioca Chips varied in moisture and salt. PCA identified that TPC, salt content, number of ingredients, and pH were key contributors to product variability. Cluster analysis confirmed Kerala Mixture as the most susceptible product to contamination risk. These findings provide valuable insights into the quality trends within an FSMS-certified environment and highlight the importance of strict post-processing controls. Full article

Two types of chito were evaluated: non-pressed (NP, immediate consumption) and pressed (P, for sale). The characteristics were analysed in samples of three years (2021–2023). The pH, water activity (a_w), proximate composition, heme iron, sodium chloride (NaCl), water soluble nitrogen (WSN), color, metmyoglobin (MMb), texture, lipid oxidation (Thiobarbituric acid reactive substances, TBARS), and microbiological analysis were evaluated, while volatile compounds were identified in NP and P. The a_w value showed a mean value of 0.70 in NP and P, values reported for typical commercial dried meat samples. However, P showed higher pH values (5.65–5.75), as well as a high level of fat (6.44–15.03%), NaCl (10.93–11.21%), lipid oxidation (3.88–6.32 mg MDA/kg meat), and hardness (223.67–574.01 N), with a browner color than NP, whereas microbial counts were similar between NP and P. Typical breakdown products derived from lipid oxidation were the main volatile compounds detected in chito, with aldehydes and alcohols being the most detected in P. The results suggest that some of the physicochemical characteristics, as well as the volatile profile, showed some differences between both types of chito, which suggests that there was a variation in the meat product associated with the making processes. Full article

The carbon metabolism activity of rhizosphere soil microbial communities is an essential indicator for assessing soil ecosystem health, as it directly affects soil nutrient cycling and the stability of organic matter. However, there is a limited understanding of the carbon metabolism characteristics of rhizosphere soil microorganisms in alfalfa (Medicago sativa L.) of different ages and their relationships with soil physicochemical properties. This study used Biolog EcoPlates to evaluate the carbon metabolism activity, functional diversity, and carbon-source utilization preferences of rhizosphere soil microbial communities in 5-, 7-, and 9-year-old alfalfa grasslands on the semi-arid Loess Plateau of western China. We analyzed the relationships between soil physicochemical properties and microbial carbon metabolism characteristics, considering their potential covariation. The results showed that, with the extension of alfalfa planting years, the rhizosphere soil water content decreased significantly, pH decreased slightly, but soil organic carbon, total nitrogen, and total phosphorus contents increased significantly. The rhizosphere soil microbial community of 9-year-old alfalfa exhibited the highest carbon metabolism activity, Shannon diversity index, and carbon-source utilization. Rhizosphere soil microorganisms from different-aged alfalfa showed significantly different preferences for carbon-source utilization, with microorganisms from 9-year-old alfalfa preferentially utilizing carbon sources such as N-acetyl-D-glucosamine, D-mannitol, and D-cellobiose. Redundancy analysis revealed that soil water content was among the most important factors influencing the carbon metabolism activity of rhizosphere soil microbial communities while acknowledging that the relative contributions of soil water content, organic carbon, and nitrogen require careful interpretation, owing to their potential collinearity. This study demonstrates that, under rain-fed conditions in the semi-arid Loess Plateau, the continuous cultivation of alfalfa for nine years led to a significant decrease in soil water content but enhanced the rhizosphere soil nutrient status and microbial carbon metabolism activity, with no apparent signs of microbial functional degradation, although soil water depletion was observed. These findings highlight the complex interactions among multiple soil factors in influencing microbial carbon metabolism, providing valuable microbiological insights for understanding the sustainability of alfalfa grasslands and a theoretical basis for the scientific management of alfalfa grasslands in the semi-arid Loess Plateau region. Future research should consider longer planting periods to determine the critical age of alfalfa grassland degradation under semi-arid conditions and its associated microbial mechanisms. Full article

This research investigates the biochemical and microbiological characteristics of a composite comprising poly(lactide) (PLA) combined with polyethersulfone (PESf) and copper-complexed cellulose phosphate (CelP-Cu). The material was produced using the pneumothermic melt-blown method and then modified with polyethersulfone and cellulose phosphate, followed by complexation with copper ions using the dip-coating technique. Comprehensive physicochemical and biological evaluations were conducted to characterize the composite. The physicochemical assessments involved elemental analysis (C, O, Cu) and morphology examination. The biological evaluations encompassed microbiological testing and biochemical–hematological analysis, including activated partial thromboplastin time (aPTT) and prothrombin time (PT). Antimicrobial activity was assessed according to the EN ISO 20645:2006 and EN 14119:2005 standards, by placing material specimens on agar plates inoculated with representative microorganisms. The results revealed that the composites exhibited significant antimicrobial effects against model microorganisms: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus atrophaeus, Candida albicans, Saccharomyces cerevisiae, Aspergillus niger, Chaetomium globosum. This study highlights the potential of PLA/PESf/CelP-Cu composites for novel biomedical applications, demonstrating their biocompatibility and their influence on hemostatic processes and antimicrobial properties. Full article

The unprecedented development of coastal cities in West Africa is marked by anarchic urbanization accompanied by ineffective environmental management, leading to water pollution. This study is conducted in the southern districts of Lomé, Togo, an area built on sandbars where inappropriate attitudes, behaviors, and inadequate hygiene and sanitation practices prevail. The objective of this study is to characterize the quality of groundwater in the study area. Bacteriological and physicochemical analyses were carried out on 11 wells in 10 districts in the southern districts during the four seasons of the year. The analysis shows that the groundwater is polluted in all seasons. Nitrate concentrations exceed 50 mg/L in 65% of the samples, while chloride levels surpassed 250 mg/L in 18% of the cases. Regardless of the season, the dominant facies is sodium chloride and potassium chloride. In all districts, the analysis of microbiological parameters including total germs (30 °C, 100/mL), total coliforms (30 °C, 0/mL), Escherichia coli (44 °C, 2/250 mL), fecal streptococci (0/100 mL), and anaerobic sulfite reducers (44 °C, 2/20 mL) reveals values exceeding the European Union standards (2007). Groundwater contamination is facilitated by the sandy nature of the soil, which increases its vulnerability to various pollutants. Togo continues to experience cholera outbreaks, aggravated by poor sanitation infrastructure and limited vaccination coverage. Public health efforts are directed toward improving sanitation and raising awareness about waterborne and non-communicable diseases. Full article

Honey is a sugar-rich product produced by Apis mellifera bees, with significant variability in properties due to the influence of geographic and climatic conditions and the predominant flora in the production region. Economically, beekeeping is an activity that generates profit and fulfills environmental and social functions, reinforcing the pillars of sustainability. This study aimed to characterize samples of honey sold in southern Brazil, including physicochemical analyses, the detection of microbiological contaminants with potential impact on human health, and the detailed identification of bacterial composition through the Next-Generation Sequencing (NGS). The present study was divided into five main stages: (1) sample collection; (2) sample fractionation; (3) physicochemical analysis; (4) microbiological analysis; (5) 16S metataxonomy analysis. The physicochemical analyses agreed with the regulated values, indicating the good quality of the honey and the absence of adulteration. The microbiological analyses indicated the absence of Salmonella spp., in addition to a low count of total coliforms. The limits for molds and yeasts were exceeded in three samples, indicating non-compliance with current MERCOSUR legislation. Metabarcoding analysis identified a total of 15,736 OTUs divided into three different genera: Bacillus (41.54%), Lysinnibacillus, and Rossellomorea, all belonging to the Bacillaceae family. Some pathogenic species were identified, namely the Bacillus cereus group and Bacillus pumilus. Our results point to an increased need for surveillance, as honey contamination can lead to public health problems, requiring improvements in legislation and control parameters. Full article

Sterlet is a perishable product; therefore, its freshness monitoring and shelf-life evaluation are important. In this study, a series of analytical techniques named physicochemical, microbiological, sensory, colorimetric, and mid-infrared and fluorescence spectroscopies were applied on Sterlet (Acipenser ruthenus) samples during 18 days of storage at 4 °C. The water content increased from 72.8 g/100 g on day 1 to 77.81 g/100 on day 14. Regarding the peroxide value (PV), the initial value was 4.17 meq/kg of Sterlet on day 1, reaching a maximum on day 4 (4.9 meq/kg of Sterlet), and then it decreased gradually, attaining a value of 0.7 meq/kg of Sterlet on day 18. Generally, the thiobarbituric acid reactive substance (TBARS), total viable count (TVC) and psychrotrophic count (PTC) increased during the storage time and increased from 0.03 to 0.13 MDA eq./kg of Sterlet sample, 2.27 to 9.09 log10 CFU/g, and 2.18 to 9.15 log10 CFU/g, respectively, on day 1 and 18, respectively. The microbiological and sensory analyses indicated that Sterlet samples were acceptable for human consumption up to 7 days of storage at 4 °C. This result was confirmed by fluorescence measurements, since the principal component analysis (PCA) applied to the NADH and MIR spectra allowed for a clear differentiation between Sterlet samples aged 7 days or less from the others. This trend was confirmed by the factorial discriminant analysis (FDA) applied to the NADH and MIR spectra, since a correct classification with leave-one cross-validation of 94.44% was observed. In addition, the heatmap of the Pearson correlation coefficients showed high correlations between overall acceptability and microbiology parameters and the structural properties of Sterlet samples during storage, indicating that the modifications observed at the macroscopic level were related to those notedat the molecular scale. Full article

In Mexico, hospital wastewater (HWW) is a source of chemical and microbiological contamination, and it is released into the municipal sewage system without prior treatment. This water may contain pathogenic bacteria and antimicrobial resistance genes, which represent a risk to Public Health and the environment. So far, there are no studies that analyse this problem comprehensively, relating bacterial population structures, chemical contaminants, and seasonality. The aim of this work was to seasonally characterise the bacterial communities of HWW, including clinically relevant bacteria and resistance genes in Hospital Juárez de México (HJM), and to evaluate the impact of physicochemical factors on their composition. A one-year observational, cross-sectional study was conducted at five HWW discharge points of HJM. Fourteen physicochemical parameters were determined by using standard methodologies, and statistical differences between discharges and seasons were evaluated. Bacterial communities were analysed by targeted amplicon sequencing of the V3-V4 region of the 16S rRNA gene. In addition, the presence of eight antimicrobial resistance genes of local epidemiological importance was assessed. Data were analysed using alpha and beta diversity indices, principal component analysis, and multivariate statistical tests. HWW showed high taxonomic diversity, with Proteobacteria, Firmicutes, and Bacteroidetes standing out. Clinically relevant bacteria were identified in 73.3% of the analyses, with Enterobacter and Escherichia-Shigella predominating. Total and dissolved solids, temperature, nitrate, and pH significantly influenced the bacterial composition of HWW. Seven out of the eight genes evaluated were identified, with bla_KPC, bla_OXA-40, and mcr-1 being the most frequent, showing significant seasonal differences. This study underlines the microbiological and chemical complexity of HWW, highlighting the impact of clinically relevant bacteria and antimicrobial resistance genes on Public Health. The findings emphasise the need to implement hospital waste management programmes and ideally specific treatment plants to minimise the associated risks and protect the environment and human health. Full article

Sodium nitrite is an additive commonly used in meat processing to provide technological effects. However, the presence of nitrates in food can lead to the formation of carcinogenic N-nitrosamines; so, its use should be limited. This study concerns the possibility of reducing sodium nitrite (III) addition in the production of canned meat to 50 mg/kg by enriching the product with tomato peels and seeds powder (TPSP). The aim of this study was to evaluate the effect of TPSP on the physicochemical, chemical and microbiological quality of canned pork. Four different products were tested in this study: a control sample and samples with the addition of 0.5%, 1.5%, and 2.5% tomato peels and seeds powder. The addition of TPSP decreased the pH values of meat products and increased yellowness (b*) and redness (a*) values. The influence of TPSP on the increase in antioxidant activity of canned meat was also observed. However, the plant-based additive did not affect the chemical composition or water activity of the tested product. The control samples were characterized by a lower TBARS compared to the other samples of meat products. Microbiological analysis results indicate that the canned pork samples meet the product requirements. The most commonly isolated species from the samples were Enterobacter cloacae, Serratia liquefaciens, and Enterococcus faecalis. Full article

Extensive cattle farming significantly contributes to Greece’s agricultural economy. In such systems, animals mainly graze on natural grasslands whose biodiversity significantly affects meat quality traits. In Greece, the sector faces several economic challenges, while the literature investigating beef quality produced by these systems is scarce. Hence, this study aimed to (i) evaluate farms’ economic performance; (ii) assess meat quality; and (iii) investigate the presence of heavy metals in liver samples of extensively reared beef cattle. The study involved three farms located in the Axios River Delta, a protected area of significant ecological importance in Northern Greece. A designated questionnaire was used to collect farm technical (herd size, meat production, grazing, feeding, reproduction, animal health) and economic data (income, variable costs). Meat samples of the Longissimus dorsi muscle (ninth rib) from 54 carcasses were collected and subjected to physicochemical (color, pH, texture, chemical composition, fatty acid profile) and microbiological analyses. Additionally, heavy metal analysis was conducted on 14 liver samples. A comparative analysis using parametric and non-parametric tests was performed to assess differences in meat quality traits between the 1st and 15th days of storage. The economic analysis showed that all studied farms operated with losses, with the average gross margin excluding subsidies being negative at EUR 130.5 ± 92.60/year per animal. Beef exhibited low fat content (1.1 ± 1.12%), with an average pH₂₄ value of 5.5 ± 0.36, respectively. The concentrations of polyunsaturated, monounsaturated, and saturated fatty acids were 2.7 ± 0.72%, 44.6 ± 4.71%, and 47.3 ± 4.91%, respectively. Over the 15-day storage period, the yellowness (b*) value (p < 0.01), hue angle (p < 0.001), cohesiveness (p < 0.01), and springiness (p < 0.01) significantly decreased, while the lightness (L*) value significantly increased (p < 0.01). The mean Total Mesophilic Viable Counts and Total Enterobacterales were 5.0 log₁₀ CFU/g and 2.34 log₁₀ CFU/g, respectively, while heavy metal concentrations in bovine livers were below the maximum limits set by the European Commission. The results suggest that, despite the financial losses observed, beef’s improved color parameters during storage, along with other favorable quality traits, highlight the potential of extensive cattle farming to meet consumer demand and support value-added marketing. Full article