Search Results (244)

Balancing microbial safety and the retention of heat-sensitive components has long been a key issue in dairy processing research. This study systematically compared the effects of instantaneous ultra-high-temperature treatment (INF, 145–155 °C/0.09 s) with that of conventional pasteurization (75–95 °C/15 s) as well as ultra-high-temperature treatment (UHT, 135 °C/5 s), on the microbial evaluation, nutritional composition, and physicochemical quality of bovine milk. The results showed that all heat treatments completely inactivated Staphylococcus aureus, coliforms, while only UHT and INF achieved full spore elimination. In the INF group, α-lactalbumin remained almost completely native and native β-lactoglobulin retention was approximately 83% relative to raw milk. The retention of lactoferrin and immunoglobulin G was about 30% and 12% after INF treatment, respectively, which were higher than that of 13% and 8% in the 85 °C/15 s group, and complete denaturation in the 95 °C/15 s and UHT groups. Furthermore, vitamin B₂ remained stable after INF treatment. The glycation content of proteins was lower in INF treatment compared to conventional heat treatments, especially for the concentration of furosine, which was about 6–7 mg/100 g protein in the INF group, and 15 mg/100 g protein in the 95 °C/15 s group, and 67 mg/100 g protein in the UHT group. Overall, the INF process achieved sterilization equivalent to UHT while substantially reducing thermal load, thus better balancing microbial safety, nutritional integrity, and immune-active proteins, which provides a scientific basis for establishing standardized INF parameters and promoting high-quality dairy production. Full article

Melanin accumulation is the primary cause of skin hyperpigmentation, and most existing cosmetic agents address this process by inhibiting melanogenesis. In contrast, strategies that directly decolorize or degrade melanin remain largely unexplored. In this study, we report a novel biobased cosmetic ingredient derived from onion (Allium cepa) associated endophytic fungi that exhibits direct melanin decolorization alongside skin-whitening and anti-aging activities. Endophytic fungi were isolated from onion tissues, and aqueous extracts were prepared to ensure cosmetic-grade compatibility. Preliminary screening demonstrated exceptional melanin-reducing capacity among the isolates, with a maximum reduction of 97.83%, highlighting their strong melanin degrading potential. A selected isolate, identified as Aspergillus brasiliensis (ACL05), was further investigated to elucidate the influence of sterilization methods on bioactivity. The autoclaved culture filtrate retained substantial melanin-reducing activity (62.85%), whereas ultrasonication-based cell inactivation resulted in significantly lower activity (32.54%), indicating that heat-stable extracellular metabolites are primarily responsible for melanin decolorization. A cosmetic essence formulated using the sterile ACL05 extract achieved a measurable melanin decolorization of 15.39%, demonstrating formulation feasibility and functional efficacy. Beyond melanin decolorization, the ACL05 extract exhibited multifunctional anti-aging properties, including inhibitory activities against tyrosinase, collagenase, and elastase, as well as significant antioxidant capacity as determined by the DPPH assay. Collectively, these findings reveal, for the first time, the potential of onion-derived endophytic Aspergillus brasiliensis as a sustainable source of multifunctional cosmetic bioactives. This work introduces a new paradigm for skin-whitening based on direct melanin decolorization while simultaneously addressing skin aging, supporting the development of next-generation biobased cosmetic ingredients. Full article

Maintaining stable male sterility is fundamental for ensuring the genetic purity and productivity of two-line hybrid wheat. However, unexpected heat events during the fertility-sensitive period can induce fertility restoration in photo-thermo-sensitive male sterile (PTMS) lines, posing a major threat to hybrid seed production. In this study, we identified two BS-type PTMS lines, BS166 and BS192, that consistently maintained sterility under heat stress in a seed-production environment, indicating strong heat-tolerant sterility. To uncover the molecular basis underlying this stability, we compared four BS-type PTMS lines exhibiting contrasting heat responses through field assessments, controlled heat treatments, transcriptome sequencing, and weighted gene co-expression network analysis (WGCNA). A total of 19,105 differentially expressed genes were identified, with the bisque4 module showing a significant correlation with seed setting rate. KEGG enrichment analysis revealed that starch and sucrose metabolism, cutin, suberin, and wax biosynthesis, fatty acid biosynthesis, and plant hormone signal transduction pathways were highly associated with heat-tolerant sterility. Core genes within these pathways displayed transcriptional stability in BS166 and BS192 but were strongly induced in heat-sensitive lines. In situ hybridization and RT-qPCR further confirmed tapetum-specific expression of TaBGLU32 and TaLACS1. Based on these findings, we propose a regulatory model explaining how PTMS lines maintain sterility stability under heat stress. Full article

Pharmaceutical industries require a continuous heat supply to sustain around-the-clock operations such as sterilization. While fossil-fuel systems ensure reliability, they increase emissions and fuel dependence. Integrating a small-scale parabolic trough collector (PTC) with concrete thermal energy storage (C-TES) enables continuous and stable solar heat delivery, offering a flexible solution for pharmaceutical manufacturing. This study investigates the integration of PTC and C-TES to provide continuous heat supply using 12 representative days of the year based on weather data for Makkah City obtained from the Renewable Resource Atlas (RRA) developed by the King Abdullah City for Atomic and Renewable Energy (K.A.CARE). Model validation was performed using experimental PTC–C-TES charging data and a simplified C-TES module model. The results show that the C-TES system successfully maintained operating temperatures between 120 °C and 310 °C. Demand coverage was identified as a key design parameter. Full demand coverage requires approximately 73 PTC units and 1600 C-TES modules, representing increases of about 4.5 and 5 times compared with the 25% coverage case. Techno-economic analysis indicates that the levelized cost of heat (LCOH) reaches an optimum of approximately 89.7 USD/MWh at 25% coverage, while overall efficiency peaks at about 41%. The results indicate that a moderate solar contribution of around 25% provides the optimal balance between cost and operational flexibility. Full article

Peracetic acid (PAA) has strong biocidal activity against bacteria, fungi, and spores, even with short contact times. PAA-mediated sterilization is therefore an attractive method for sterilization of growth media that have heat-labile components or when polymer-based equipment is used. However, residual PAA and co-existing hydrogen peroxide (H₂O₂) can inhibit the growth of cultivated species, necessitating a fast and reliable quenching strategy that does not require rinsing. In contrast to Fe–EDTA-based catalytic decomposition that is strongly influenced by pH, buffers, and organic nitrogen, we demonstrate a fundamentally different, stoichiometric quenching strategy using sodium dithionite that enables instantaneous and selective removal of PAA. Na₂S₂O₄ preferentially reduced PAA over H₂O₂ in a 0.03% PAA solution and achieved complete PAA reduction within 5 s, independent of pH and in the presence of nitrogen compounds. By adjusting the Na₂S₂O₄ dose, PAA could be selectively removed while allowing a small fraction of H₂O₂ to remain. When applied to the cultivation of Euglena gracilis, which tolerates low levels of H₂O₂, the PAA–Na₂S₂O₄-treated medium resulted in greater cell growth and higher paramylon production than autoclaved medium. Full article

Poly(3,4-ethylenedioxythiophene)–polystyrene sulfonate (PEDOT:PSS) is widely used to fabricate conductive organic coatings for electrodes in electrophysiology. As these devices move toward clinical translation, establishing sterilization methods that preserve their functional properties is essential. Ethylene oxide (EtO) is routinely used for sterilizing heat- and moisture-sensitive medical devices due to its high penetration efficiency and low thermal load. However, the absence of systematic studies evaluating its impact on PEDOT:PSS raises concerns about the compatibility of EtO sterilization with organic electrophysiology interfaces. Here, we report the first comprehensive evaluation of EtO sterilization on PEDOT:PSS electrodes electrochemically deposited onto cortical interfaces designed for intraoperative monitoring and stimulation. EtO exposure induced only minimal changes in surface topography, with no detectable alteration of the electrical or electrochemical performance of the electrodes. Impedance spectroscopy, cyclic voltammetry, and charge-injection capacity measurements all revealed that EtO-treated electrodes retained properties comparable to untreated controls. Moreover, EtO-sterilized PEDOT:PSS coatings demonstrated robust long-term stability under accelerated lifetime testing, exhibiting negligible degradation over extended operation. These findings demonstrate that EtO sterilization is fully compatible with PEDOT:PSS-based bioelectronic interfaces and constitutes a viable pathway toward their safe and effective integration into clinical electrophysiology. This work represents an important step toward translating organic conducting polymer technologies into real-world biomedical applications. Full article

This study provides a comprehensive three-dimensional Computational Fluid Dynamics analysis of airflow distribution in a surgical operating room under realistic occupancy and equipment conditions. Using integrated modelling in SolidWorks and a subsequent analysis in ANSYS Fluent, a full-scale Operating Room geometry was simulated to assess the effectiveness of a laminar airflow system. The model includes surgical staff mannequins, thermal loads from surgical lights, and medical equipment that commonly disrupt unidirectional flow patterns. A polyhedral mesh with over 2.8 million nodes was employed, and a grid independence study confirmed solution reliability. The realisable k–ε turbulence model with enhanced wall treatment was used to simulate steady-state airflow, thermal stratification, and pressure variation due to door opening. Results highlight significant flow disturbances and recirculation zones caused by the shear zone created by supply air, overhead lights and heat plumes, particularly outside the core laminar air flow zone. The most important area, 10 cm above the surgical site, shows a maximum velocity gradient of 0.09 s⁻¹ while the temperature gradient shows 6.7 K.m⁻¹ and the pressure gradient, 0.0167 Pa.m⁻¹. Streamline analysis reveals potential re-entrainment of contaminated air into the sterile field. Full article

This study developed a process for producing prebiotic-fortified instant rice macaroni to diversify rice-based convenience foods. Resistant starch (RS) rice flour from three varieties—IR504 and two pigmented, anthocyanidin-rich rice cultivars (Huyet Rong and MS2019)—was blended with wheat flour and fixed ingredients (tapioca starch, salt, and vegetable oil at a ratio of 9g:1g:1g), together with hot water. The instant rice macaroni with the highest RS content (11.64%) was obtained using IR504 RS and wheat flour (44:6), gelatinized at 100 °C for 20 min, microwaved at 36 W/g for 30 s, retrograded at 4 °C for 24 h, and sterilized at 115 °C for 15 min. For anthocyanidin-containing macaroni, the combination of Huyet Rong RS and wheat flour (39:11) yielded 9.47% RS under similar retrogradation and sterilization conditions, but with a shorter gelatinization step (100 °C, 15 min) and longer microwave treatment (50 s at 27 W/g). The other optimized colored-RS formulation was based on MS2019 RS and wheat flour (21:29) processed under similar conditions. All optimized formulations exhibited lower estimated glycemic index (eGI) values of 64.1, 65.7, and 68.2, which were significantly lower than those of the control instant rice macaroni (78.2–85.9, p < 0.05). This study confirms the potential of developing instant rice macaroni rich in RS to enhance prebiotic effects that support the growth of beneficial intestinal bacteria, strengthen immune function, and improve nutritional quality through the incorporation of anthocyanidin-rich rice varieties and a processing procedure combining heat–moisture treatment with microwave heating. Full article

As the exposure of the aquatic ecosystem to graphene oxide (GO) increases with its growing production and use, understanding the structure–property–toxicity relationships becomes increasingly critical in the development of effective safe design guidelines. An appropriate testing methodology is crucial in ecotoxicity assessments to accurately characterize the environmentally relevant toxicity of nanoparticles, particularly for GO, where the physicochemical properties fundamentally determine their interactions and toxicity toward aquatic organisms. Many ecotoxicological methods require the heat sterilization of samples as a preliminary treatment prior to analysis. To investigate changes in toxicity profiles induced by wet heat sterilization pretreatments (autoclaving and Tyndall treatment) of a well-characterized GO product, a comprehensive ecotoxicological evaluation was performed with Daphnia magna. This included conventional lethality and immobilization tests, along with sublethal endpoints such as heart rate and feeding activity, supplemented with the analysis of oxidative stress biomarkers. Physicochemical alterations in GO due to sterilization were examined with dynamic light scattering, ultraviolet-visible, and thermogravimetry/mass spectrometry. Sublethal endpoints were shown to be more sensitive indicators of toxicity than conventional methods, with feeding activity and heart rate inhibition demonstrating time and concentration-dependent effects. Heat-sterilized GOs exhibited greater ecotoxicity compared to pristine GO, as evidenced by elevated ROS levels and increased oxidative stress biomarkers (GPx and GST activities), implicating oxidative stress as a central mechanism of toxicity. Despite the subtle differences observed in the physicochemical properties, the impact of heat sterilization on toxicity is clear. Our research underscores the critical importance of adopting appropriate testing and evaluation methodologies for comparing GO ecotoxicity results under axenic and non-axenic conditions as well as a multimarker approach to accurately evaluate the risks posed by GO. Full article

This study aimed to evaluate the impact of UVC (Ultraviolet C Radiation), detergent foam, and alcohol (70%) sterilization methods on the surface morphology of acrylonitrile–butadiene–styrene (ABS) specimens using a novel SEM (Scanning Electron Microscope) image processing approach. Twelve 3D-printed specimens were prepared, and five concentric circular regions of interest (ROIs) per specimen were analyzed. Three quantitative descriptors—defect area fraction, anisotropy ratio, and RMS (Root Mean Square) roughness—were extracted to assess surface alterations. To validate the image-based findings, EDX (Energy-Dispersive X-ray Spectroscopy) elemental analysis for carbon (C), nitrogen (N), and oxygen (O) was employed as a complementary and traditional benchmark technique. Statistical comparisons and p-value heat maps revealed strong convergence between SEM and EDX results. UVC sterilization consistently preserved surface morphology and elemental stability, showing the lowest defect fraction (p = 0.2684), balanced anisotropy (p = 0.02481), and minimal oxygen incorporation (O = 7.6). Foam sterilization produced intermediate effects, with significant anisotropy changes (p = 0.007456) and reduced nitrogen (19.6). Alcohol sterilization induced the most severe damage, characterized by high defect density, increased roughness, and elemental imbalance (N = 17.3, O = 13.9), confirming oxidative degradation. The convergence of SEM and EDX outcomes demonstrates that SEM image processing is a reliable novel method validated by traditional elemental analysis. Together, these approaches provide a robust framework for ranking sterilization efficacy, with UVC identified as the most favorable method, detergent foam as an acceptable alternative, and alcohol as the least effective due to its destabilizing effects. Full article

Sterilization of medical devices is a critical process to ensure patient safety. However, traditional steam autoclaves may be unsuitable for heat-sensitive materials. In this study, we evaluated an innovative cold sterilization system based on the controlled generation of free radicals with reducing properties. The system has already been validated and marketed following the completion of numerous microbiological tests in compliance with UNI EN standards (13727, 13624, 17126, 14476, 14348). A quantitative suspension test was conducted under controlled conditions, comparing the microbial reduction achieved with the cold system to that obtained with a standard autoclave cycle. The system demonstrated bactericidal efficacy exceeding 6 log₁₀, comparable to that of the autoclave cycle. The results suggest that the free radical system represents a safe, rapid, and effective alternative for the sterilization of heat-sensitive materials, with potential applications in both healthcare and industrial settings. Full article

The escalating crisis of bacterial antimicrobial resistance poses a severe threat to global health, necessitating novel strategies beyond conventional antibiotics. Photothermal therapy (PTT) has emerged as a promising alternative that leverages heat generated by laser irradiation to induce localized cellular damage and eradicate bacteria. Among various photothermal agents, carbon-based nanomaterials like graphene nanoplatelets (GNPs) offer exceptional properties for PTT applications. This study introduces a novel urinary catheter (UC) embedded with GNPs (GNPUC), specifically designed for photothermal sterilization to combat catheter-associated bacterial infections. GNPs were systematically incorporated into polydimethylsiloxane (PDMS) catheters at varying weight percentages (1% to 10%). The fabricated GNPUCs exhibited low wettability, hydrophobic characteristics, and low adhesiveness, properties that are crucial for minimizing bacterial interactions and initial adhesion. Upon exposure to near-infrared (NIR) laser irradiation (808 nm, 1.5 W/cm²), the UC containing 10 weight percent of GNPs (10GNPUC) achieved a significant temperature of 68.8 °C, demonstrating its potent photothermal conversion capability. Quantitative agar plate tests confirmed the enhanced, concentration-dependent photothermal antibacterial activity of GNPUCs against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Notably, 5% and higher GNP concentrations achieved 100% mortality of S. aureus, while 1% and higher concentrations achieved 100% mortality of E. coli. These findings underscore the significant potential of GNP-embedded catheters as a highly effective photothermal antibacterial platform for future clinical applications in combating catheter-associated infections. Full article

Background: Airborne transmission of bacteria, viruses, and fungal spores poses a major threat in enclosed settings, particularly nursing homes where residents are highly vulnerable. Compressive Heating Air Sterilization Technology (CHAST) applies compressive heating to inactivate microorganisms without reliance on filtration or chemicals. Methods: CHAST efficacy was evaluated in laboratory and deployed for a feasibility and performance validation study of air sterilization in a nursing home environment. Laboratory studies tested prototypes (300–5000 CFM; 220–247 °C) against aerosolized surrogates including Bacillus globigii (Bg), B. stearothermophilus (Bst), B. thuringiensis (Bt), Escherichia coli, and MS2 bacteriophage. Viral inactivation thresholds were further assessed by exposing MS2 to progressively lower treatment temperatures (64.5–143 °C). Feasibility and performance validation evaluation involved continuous operation of two CHAST units in a nursing home, with pre- and post-treatment air samples analyzed for bacterial and fungal burden. Results: Laboratory testing demonstrated consistent microbial inactivation, with most prototypes achieving > 6-log (99.9999%) reductions across bacterial spores, vegetative bacteria, and viruses. A 5000 CFM prototype achieved > 7-log (99.99999%) elimination of B. globigii. MS2 was completely inactivated at 240 °C, with modeling suggesting a threshold for total viral elimination near 170 °C. In the feasibility study, baseline sampling revealed bacterial (35 CFU/m³) and fungal (17 CFU/m³) contamination, dominated by Bacillus, Staphylococcus, Cladosporium, and Penicillium. After 72 h of CHAST operation, discharge air contained no detectable viable organisms, and fungal spore counts showed a 93% reduction relative to baseline return air. Units maintained stable operation (464 °F ± 2 °F; 329–335 CFM) throughout deployment. Conclusion: CHAST reproducibly and scalably inactivated airborne bacteria, viruses, and fungi under laboratory and feasibility field studies, supporting its potential as a chemical-free strategy to improve infection control and indoor air quality in healthcare facilities. Full article

Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) are E. coli pathovars of particular relevance to infant health. While the intestinal tract of humans and animals constitutes their primary habitat, these bacteria can also persist in natural environments such as sand. The aim of this study was to evaluate the persistence of STEC and EPEC strains in sand microcosms under controlled conditions of heat and desiccation in order to estimate their viability in this matrix and provide evidence regarding the potential risks associated with the use of sandboxes in public spaces. The study included STEC strains belonging to clinically important serotypes (O26:H11, O103:H2, O111:H8, O121:H19, O145:NM, O157:H7 and O174:H28), animal-derived EPEC strains, and a non-pathogenic E. coli strain (NCTC 12900). The strains were inoculated into sterile sand microcosms and maintained at 37 °C. Death curves, persistence in the matrix, presence of virulence genes, and ability to produce biofilm were evaluated. The death and persistence curves varied by serotype; some strains remained viable in the viable but non-culturable state for extended periods. All strains retained their virulence-associated genetic markers throughout the assays. None of the STEC strains was classified as a biofilm producer under the experimental conditions, whereas the two EPEC strains were identified as weak and moderate biofilm producers. However, no association was found between biofilm formation and persistence in the matrix. The findings provide an initial approach and provide relevant evidence of the capacity of STEC and EPEC strains to survive in sand, which could represent a potential risk in recreational environments. Full article

The most significant barrier against biopolymers’ commercialization is their sensitivity to external factors and poor material properties. In recent years, significant progress has been made to enhance these materials so that they are able to provide their unique physiological benefits while maintaining acceptable material performance. As these materials have developed, so too has their application in the food and medical industry, which often requires them to undergo sterilization. Sterilization is a process in which all microbial life and spores are removed from the surface and within materials and is a regulatory requirement for some food packaging products and all medical applications. Sterilization is carried out primarily using radiation, chemical, and heat treatment, which are all effective in disrupting cell regulation and causing cell death. These processes are known to induce structural and/or chemical changes in materials as well as potential migratory or leaching effects. This review aims to provide a comprehensive evaluation of these sterilization processes and the effects they have on polysaccharides, while established data is discussed that provides insight into their market viability post-sterilization and the importance of further characterization using sterilization. Full article