Search Results (287)

Chromium-related hazard in mine wastes depends strongly on oxidation state, with hexavalent chromium [Cr(VI)] representing the most mobile and toxicologically relevant chromium form. Abandoned tailings dumps can develop sharp pH and redox gradients that favour either Cr(VI) persistence or attenuation, yet field-based evidence from Eastern European post-mining sites remains limited. This study evaluates the Defor Petrila tailings dump, Jiu Valley, Romania, as a first-tier environmental hazard-screening case study based on repeated monitoring performed during 2022–2024 at twelve permanent sampling points and two local operational control samples. Field pH and redox potential (Eh), moisture, organic matter, acid-extractable Mn and Fe, pseudo-total Cr, and method-defined extractable Cr(VI) were determined. Here, pseudo-total Cr refers to chromium released by microwave-assisted acid digestion and does not represent complete decomposition of the silicate matrix, while extractable Cr(VI) refers to the operationally defined fraction obtained by alkaline extraction. In addition, a conservative redox-based prioritisation score (R_redox) was applied only as an internal ranking layer to identify sectors where Cr(VI) is more likely to persist. The upper dump sector (P1–P4) was alkaline (pH 7.5–8.2), strongly oxidising (+280 to +412 mV), and enriched in Mn and Fe, whereas the lower sector (P9–P12) was wetter, slightly acidic to near-neutral, and reducing (−59 to −10 mV). Extractable Cr(VI) reached 18.7 mg kg⁻¹ at P2 in 2024, while both control samples remained below the quantification limit. Exploratory repeated-site statistics, sector-based comparison, and correlation analysis supported a coherent association between Eh, Mn enrichment, and extractable Cr(VI), but these relationships are interpreted as spatially structured screening evidence rather than proof of a single mineralogical oxidation pathway. No direct exposure, leachability, bioaccessibility, ecotoxicity, airborne dust, water, vegetation, or biomonitoring measurements were included; therefore, the results identify priority zones for confirmatory toxicological and exposure-based assessment, not receptor-specific risk estimates. This study demonstrates that combining chromium speciation with field redox zonation can support conservative monitoring prioritisation at abandoned mine-waste sites where the toxic form of chromium may remain environmentally active. Full article

Environmental contamination with potentially toxic elements is a growing concern for ecosystem quality and food safety. This study evaluated the relationships between environmental conditions, anthropogenic activities, and the elemental composition of Prunus spinosa fruits collected from western and central Romania along a pollution gradient. Eighty samples from ten sites representing non-polluted, agricultural, traffic-exposed, and mining-affected areas were analyzed by ICP-MS after microwave digestion. Fruits from impacted areas showed compositional differences, including lower concentrations of some essential macroelements and higher levels of several trace elements potentially associated with anthropogenic pressure. Increased sodium, aluminum, and silicon contents were consistent with environmental stress and enhanced environmental exposure and possible soil-derived particulate influence, while boron and molybdenum declined with pollution intensity. Elemental patterns were mainly associated with local environmental conditions and appeared consistent with site-specific environmental influences. Food safety assessment indicated generally low to moderate risk depending on sampling origin. Overall, Prunus spinosa fruits showed potential as a bioindicator of environmental quality and a useful tool for monitoring anthropogenic contamination. Full article

Effective management of organic wastes is essential for green and low-carbon development. Conventional technologies, including incineration, pyrolysis, hydrothermal carbonization (HTC), gasification, anaerobic digestion (AD), and composting, have supported waste reduction and basic resource recovery, but they remain limited in high-efficiency conversion and high-value utilization. This review comparatively evaluates these conventional routes together with advanced and intensified technologies, including microwave-assisted pyrolysis (MAP), plasma treatment, supercritical water gasification (SCWG), and flash joule heating (FJH), with emphasis on suitable feedstocks, performance characteristics, application boundaries, and integration potential. In general, wastes with high moisture content are more suitable for HTC, AD, and SCWG, whereas relatively dry wastes and wastes with high carbon content are more suitable for pyrolysis, gasification, plasma treatment, and FJH upgrading. The review also discusses representative integrated pathways, such as HTC-SCWG, pyrolysis and plasma coupling, AD and gasification coupling, and pyrolysis and FJH coupling, which may improve carbon conversion, broaden product portfolios, and reduce residual pollutants. However, large-scale implementation is still constrained by feedstock heterogeneity, heat and mass transfer limitations, catalyst deactivation, reactor corrosion, and system cost. Overall, no single technology is universally optimal; technology selection should depend on feedstock properties, moisture content, and target products. Full article

Wheat starch serves as a major dietary carbohydrate. Optimizing its structural and functional properties is essential for developing health foods. In the present study, microwave-assisted heat–moisture treatment (MHT) was applied to modify wheat starch and the effects of the physical treatments on its structure and digestibility were investigated. X-ray diffraction analysis revealed that the crystallinity of wheat starch slightly decreased after MHT. Ion chromatography revealed changes in the chain length distribution of wheat starch after modification, with a continuous increase in short-chain components over treatment time. MHT enhanced the enzymatic resistance of wheat starch, which resulted in a resistant starch content of 36.89% after 1.5 h of MHT. Excess heat disrupted the ordered structure of starch when the treatment was extended to 2 h, leading to a slight reduction in enzymatic resistance. The study provided a theoretical basis for designing functional starch ingredients through low water content physical treatment. Full article

Natural honey is a widely consumed product in various cultures. Owing to the foraging behaviour of bees and the unique production process of honey, this matrix serves as a critical tool for environmental biomonitoring. The aim of this study was to assess the content of selected toxic elements, specifically cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg), in honeys from Poland and Algeria. Additionally, the existence of health risks associated with long-term consumption was assessed. The As, Cd, and Pb content was determined using ICP-MS after prior microwave digestion of the samples in a closed system. Hg content was determined directly using the AAS method with the amalgamation technique. A total of 41 honey samples from Algeria and Poland were analysed. The content of the tested toxic elements in most samples was low. The results obtained for Pb were compared to applicable standards; exceedances for Pb were observed in 7% of the samples. Despite this, the estimated exposure did not indicate a significant health risk to consumers. The above data indicate that honey is not only a valuable nutritional product but also represents an important bioindicator of environmental pollution. Full article

The mechanistic impact of drying technologies on phenolic stability and gastrointestinal bioaccessibility in aronia remains poorly defined, limiting the development of functionally optimized dried berry products. This study aimed to comparatively evaluate the effects of different drying techniques—hot air drying (60, 70, and 80 °C), vacuum drying (60, 70, and 80 °C; 150 mbar), and microwave drying (180 and 360 W)—on total phenolic content (TPC), total antioxidant capacity (TAC) assessed by DPPH, CUPRAC, and FRAP, and total monomeric anthocyanins (TMA) during in vitro gastrointestinal digestion. UHPLC-DAD analysis showed that the phenolic profile was dominated by chlorogenic acid, catechin, caffeic acid, epicatechin, and quercetin. Drying enhanced extractable TPC, while TAC with DPPH and FRAP showed increasing trends and CUPRAC decreased after drying. Color changes indicated increased redness and pigment concentration following dehydration. Simulated digestion induced substantial losses in TPC (53–59%) and TMA (30.5–72.8%), alongside marked reductions in FRAP and CUPRAC, whereas DPPH activity increased significantly, suggesting matrix-driven transformation and release of antioxidant compounds under gastrointestinal conditions. Among the applied methods, vacuum drying (70 °C; 150 mbar) exhibited superior stability in terms of antioxidant and anthocyanin preservation during digestion. Overall, the findings demonstrate that drying-induced structural modifications play a key role in governing phenolic stability and bioaccessibility, providing new insights into the mechanisms underlying the functional behavior of dried berry products. Full article

This paper presents a comparative determination of rare earth elements (REEs) in sandstone-type uranium ore samples from Kazakhstan using a proposed rapid ICP-MS method following microwave digestion in a MARS 6 system with a mixed acid solution of HNO₃, HCl, and HF. To validate the rapid REE determination method, comparative measurements were performed using a certified uranium ore reference material provided by Ore Research & Exploration, representing sandstone-hosted uranium mineralization from a Tanzanian deposit (OREAS 120). Fractionation patterns of chondrite-normalized REEs in uranium ores from Kazakhstan were evaluated. Comparative data on REE distribution in sandstone- and magmatic-type uranium deposits from Australia and Tanzania are presented. Uranium ores of magmatic- and sandstone-hosted types exhibit distinct REE distribution patterns, reflecting differences in the nature of ore-forming processes. This study provides chondrite-normalized REE distribution profiles for major uranium deposit types from three countries, which are subsequently used to assess uranium ore paragenesis through simple linear regression analysis. This study is intended as an applied comparative synthesis of REE fractionation patterns in genetically contrasting uranium deposits, with particular relevance to deposit classification. Full article

Heavy metals in agricultural systems pose a significant challenge to food security, especially in regions with long-term intensive land use. While the Pannonian Plain represents Croatia’s primary breadbasket, accounting for a significant portion of the nation’s cereal production, data on the soil-to-grain transfer of heavy metals and the associated human exposure risk are limited. The objective of this study was (i) to determine the concentrations of arsenic (As), cadmium (Cd), and lead (Pb) in agricultural soils and corresponding grains (wheat, barley, and maize) across four principal counties within the Pannonian region of Croatia; (ii) to evaluate the soil-to-grain transfer factors that varied regionally and among cereal types; and (iii) to assess the potential non-carcinogenic health risks for both adults and children highlighting differences in exposure due to body weight and consumption patterns. Soil and cereal grain samples were collected in 2019 and 2020, and metal concentrations were determined by ICP-MS after microwave acid digestion. The transfer of metals from soil to grain was estimated using the transfer factor (TF), while exposure assessment was conducted by calculating the estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI). Due to the nonlinear distribution of the data and the lack of strictly matched soil and grain samples, median metal concentrations pooled across all studied regions were used for exposure assessment. For As, a conservative approach was applied, assuming that 50% of the total As is in inorganic form. Additionally, a probabilistic risk assessment using Monte Carlo simulations was conducted to account for variability in body weight and cereal intake, providing a more comprehensive evaluation of potential exposure. The results showed differences in metal accumulation among cereal species, with wheat and barley tending to accumulate more Cd than maize, while As and Pb concentrations in grains were low for all crops studied. Although soil metal concentrations in Međimurje County were generally low, elevated TF values for As and Pb were observed, indicating enhanced soil-to-plant transfer under specific local soil conditions. In contrast, high soil metal concentrations in Slavonski Brod–Posavina County were associated with low TF values, suggesting limited bioavailability and restricted transfer to cereal grains. Both deterministic and probabilistic assessments indicated that the HQ and HI for adults and children were below 1, suggesting low non-carcinogenic risk from cereal consumption. These findings highlight pronounced regional and crop-specific differences in soil-to-plant metal transfer and confirm that low soil contamination does not necessarily imply low transfer potential, emphasizing the importance of integrated soil–plant–grain monitoring for food safety assessment. Full article

Growing concern over the presence of microplastics in food has led to the development of numerous methods for their extraction and analysis. However, many of these methods are time-consuming and limited to specific food types. In this study, we present a novel and quick approach involving microwave-assisted acid extraction of microplastics from food, followed by Raman microscopy analysis. The method’s performance was evaluated through determination of its digestion efficiency, particle mass and number recovery, limit of detection (LOD), and the digestion protocol’s effect on polymer physicochemical characteristics. The extraction protocol achieved 99.74–100.01% digestion of four different food matrices within 2 h, with 81.4–110.7% mass and 80–108% number recoveries of added polymer particles, both being within the 80–120% range. Importantly, DSC, TGA, DLS and Raman analyses of added particle polymers showed no significant change in PE, PP and PTFE polymer structure, while some structural changes were found for PET and PMMA. This method’s good analytical performance, high throughput and suitability for quick digestion of several different food matrices make it a promising step towards reliable monitoring of microplastics in food. Full article

This study evaluated the influence of four thermal pretreatment techniques—autoclaving, hot-air oven treatment, hot-water immersion, and microwave irradiation—on Parthenium hysterophorus biomass to improve its biodegradability and biogas generation potential under batch anaerobic digestion. Among the investigated methods, hot-air oven pretreatment at 110 °C for 90 min exhibited the most significant enhancement in biomass solubilization, as indicated by a 51.5% rise in soluble chemical oxygen demand (sCOD) and an increase in volatile fatty acids (VFAs) compared with the untreated control. These compositional improvements facilitated faster hydrolysis and led to a 25.73% higher cumulative methane yield in biochemical methane potential (BMP) assays. Structural analysis revealed pronounced alterations in the lignocellulosic matrix, with reductions in hemicellulose and partial delignification improving substrate accessibility. Complementary characterisation using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) confirmed the disruption of crystalline cellulose regions and modification of functional groups, supporting the observed biochemical improvements. Collectively, the results demonstrate that hot-air oven pretreatment is a practical and energy-efficient approach for enhancing the digestibility of P. hysterophorus biomass, promoting its utilisation as a sustainable feedstock for renewable biogas production and environmental management of this invasive weed. Full article

Mycelium-based composites (MBCs) have emerged as promising biofabricated materials that align with circular economy and clean technology goals by utilizing fungal networks to transform lignocellulosic residues into functional, biodegradable composites. Despite the MBC’s potentials, the intrinsic nature of the fungal strain, substrate physico-chemical composition and engineering property variability remain significant hurdles that should be critically surmounted. Substrate treatment is central to determining growth kinetics, microstructural uniformity, and mechanical performance in MBC production. This review highlights recent advancements in physical, chemical, biological, and hybrid pretreatment methods, including comminution, pasteurization, alkali hydrolysis, enzymatic conditioning, microwave-assisted hydrolysis, ultrasound pretreatment, steam explosion, plasma activation, and irradiation. These technologies collectively enhance substrate digestibility, aeration, and permeability while reducing contamination. Optimization parameters—temperature, pH, C:N ratio, moisture content, particle size, porosity, and aeration—are examined as critical process levers influencing hyphal density, bonding efficiency, and composite uniformity. Evidence suggests that properly engineered substrate treatments accelerate colonization, strengthen hyphal networks, and significantly improve compressive, tensile, and flexural material properties. The review discusses emerging process control tools such as AI-assisted modeling, micro-CT porosity analysis, and sensor-integrated bioreactors that enable reproducible and energy-efficient fabrication. Collectively, the findings position substrate engineering as a foundational technology for scaling high-performance mycelium composites and advancing sustainable material innovation. Full article

The incorporation of spore-forming probiotics into thermally processed foods represents a promising strategy to expand functional food availability. In this study, probiotic snacks were formulated from oat and rice-bean matrices as delivery vehicles for Heyndrickxia coagulans (formerly Bacillus coagulans) BC4 spores. The effects of baking and microwave processing, packaging, and storage conditions on spore viability and functionality were evaluated. While oven baking (180 °C) preserved viability in both matrices under mild conditions (survival > 90%), dielectric heating induced significant viability loss depending on the matrix. The starch-based rice-bean matrix, characterized by higher post-processing water activity (Aw), suffered a thermal runaway effect, resulting in significant spore inactivation (viability decreased to 6.08 log colony forming units/g (CFU/g); 1.5 min). Conversely, the oat matrix acted as a thermo-physical stabilizer, maintaining high viability (9.41 log CFU/g; 1.5 min) by limiting dielectric energy absorption via its fiber-lipid composition. Oxidative stress and premature germination likely contributed to the viability loss observed in atmospheric packaging during the 30-day storage. The oat matrix mitigated this effect through a dual-protective mode: active radical scavenging (validated by superior ferric reducing ability of plasma (FRAP) values) and passive water binding. Simulated digestion data align with the functional preservation observed, resulting in increased survival for oat-based formulations. Overall, the results demonstrate the feasibility of developing oat and rice-bean snacks enriched with H. coagulans spores and highlight the critical role of matrix and processing conditions in preserving probiotic viability. Full article

Table grapes are commonly consumed fresh, and their market value is largely determined by ripeness, grape color, mineral composition, and variety-specific aroma. This study integrated physicochemical ripening indicators (°Brix%, pH, titratable acidity, maturity index), CIELAB color parameters measured on the outer skin and inner sections, multi-element mineral profiling following microwave-assisted digestion (ICP-MS), and volatile organic compound (VOC) profile by HS-SPME/GC-MS to characterize five table grape varieties (Thompson Seedless, Isabella, Mevlana, Pepita Alfonso, and Red Globe). Significant differences in ripeness were found among the varieties (p < 0.01). Isabella had the highest soluble solids content (22.91 °Brix%), while Pepita Alfonso had the highest maturity index (79.89) and the lowest titratable acidity (0.22%). Color measurements also showed significant differences among the varieties (p < 0.01). Thompson Seedless exhibited the highest peel lightness/yellowness and chroma values, while Pepita Alfonso and Red Globe had a darker, lower chroma profile. Color index values differed between the peel and the inner cross-section depending on the variety (p < 0.01). Mineral composition was found to be variety-specific (p < 0.01). The dominant macroelements among the samples were K, P, and Mg, and statistically significant differences were also determined in trace elements (p < 0.01). A total of 42 volatile organic compounds (VOCs) were identified. Aldehydes were dominant in the volatile fraction (39.07–64.96%), nonanal contributed a significant percentage, and terpenoids (floral aroma note) were found in the highest percentage in the Isabella variety (28.87%). PCA applied to the integrated physicochemical, color, and mineral dataset enabled the clear discrimination of the five table grape cultivars. Pepita Alfonso was positioned toward positive PC2, and Red Globe occupied the opposite segment. Thompson Seedless and Isabella were separated mainly along PC1, while Mevlana showed an intermediate profile. SIMCA class-distance results confirmed the visual separation. All pairwise interclass distances were above the decision threshold (ICD > 3), ranging from 62,922 (Red Globe–Mevlana) to 806,425 (Isabella–Pepita Alfonso). Findings indicated robust cultivar-level classification for authenticity and quality control purposes. Overall, the integrated multi-domain approach is considered to provide a solid foundation for variety differentiation and quality-oriented harvesting and market management. Full article

Cephalopods and crustaceans are known to bioaccumulate heavy metals, potentially posing both non-carcinogenic and carcinogenic health risks to consumers. This study was conducted to determine heavy metal concentrations and assess associated health risks in the edible tissues of 84 cephalopod and crustacean samples. Heavy metal concentrations and assess associated health risks in the edible tissues of 84 cephalopod and crustacean samples collected from selected wholesale markets and major fish landing ports throughout Peninsular Malaysia. The analysis focused on nine heavy metals: selenium (Se), cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), antimony (Sb), tin (Sn), chromium (Cr), and manganese (Mn). The samples were digested using a microwave digestion system, and heavy metal concentrations were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results showed that Mn was the most abundant metal, followed by Cr and Zn. Octopus (C. indicus) had the highest Mn concentration (5.01 mg/kg WW), while Rainbow shrimp (P. sculptilis) had the highest overall metal concentration (91.02 mg/kg WW). Significant differences were observed between cephalopods and crustaceans, with Cd and Sn concentrations being notably higher in cephalopods (p < 0.001). However, no significant associations were observed between heavy metal concentrations and sample weight or length, indicating a greater influence of environmental factors. Principal Component Analysis (PCA) explained 80.4% of the variance, with Cd, Sn, Pb, Cu, Zn, Cr, and Mn accounting for the majority of the variance. Estimated weekly intake (EWI) values ranged from 0.002 to 26.30 µg/kg bw/week for cephalopods and 8.02 × 10⁻⁶ to 243.175 µg/kg bw/week for crustaceans. All metal levels were below the permissible limits set by the Food and Agriculture Organisation of the United Nations/World Health Organisation (FAO/WHO). Hazard Index values were <1, indicating low non-carcinogenic risk, and Total Carcinogenic Risk values for Pb and Cr were below 1 × 10⁻⁴, suggesting negligible carcinogenic risk. Full article

Whole grains, due to their intact structure, retain more nutrients and offer significant health benefits. Thermal modification is commonly applied to modify cereal grains. This study aimed to investigate the effects of thermal treatments (microwaving (abbreviation MW-BW), roasting (RST-BW), and an emerging technology, heat fluidization (HFL-BW)) on whole-grain black wheat flour. The results showed minimal loss in proximate composition and increased anthocyanin content (from 38.78 mg/kg (BW) to 39.57 (HFL-BW) and 46.06 mg/kg (MW-BW)) relative to the control. Analysis of physical properties and microstructure revealed that all thermal treatments caused kernel swelling, darkened the flour color, decreased the kernel hardness, and disrupted the starch microstructure. All thermal treatments disrupted starch short-range order and reduced crystallinity (from 26.75% (BW) to 2.56 (HFL-BW) and 15.74% (RST-BW)), resulting in a transformation to a V-type structure. The protein secondary structure (mainly for α-helix) was disrupted, and gluten was denatured and aggregated in all thermal-treatment groups. Thermal treatments decreased gelatinization enthalpy (from 4.76 J/g (BW) to 0.59 (HFL-BW) and 4.44 J/g (RST-BW)) and altered pasting viscosity. The viscoelasticity of pastes made from thermal treatments was improved. In vitro digestibility results showed that thermal treatments decreased starch digestibility, decreased the protein bioavailability, and increased resistant starch content (from 20.1% (BW) to 30.9 (MW-BW) and 39.6% (RST-BW)). Altogether, heat fluidization had the most pronounced effect among the treatments. Thermal modifications—particularly heat fluidization—are promising technologies for enhancing the quality of whole-grain black wheat flour and developing functional foods. Full article