Background: Organophosphorus pesticides (OPPs), particularly chlorpyrifos and phoxim, are lipophilic contaminants of environmental and food-safety concern in dairy systems. These OPPs exhibit sufficient chemical stability to persist through milk processing and storage even though neither compound is classified as a Persistent Organic Pollutant (POP) under the Stockholm Convention. Moreover, these OPPs pose public health risks through neurotoxicity, endocrine disruption, and bioaccumulation in high-fat matrices such as buffalo milk. Objective: Thus, this study aimed to compare and evaluate ultrasonication, ultraviolet (UV)/titanium dioxide (TiO2) photocatalysis, and lactic acid bacteria (LAB) fermentation to reduce chlorpyrifos and phoxim concentrations in artificially spiked buffalo milk. Methods: Residues were quantified by Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction coupled with gas chromatography–mass spectrometry (GC-MS). Sonication (100 W, 37 kHz) was applied for up to 20 min; UV/TiO2 (254 nm; 50–200 mg TiO2/100 mL) for up to 60 min; and three LAB preparations were individually inoculated into spiked pasteurized milk and incubated for 24 h (n = 3; p < 0.05). Results: Sonication achieved removal efficiencies of up to 66.81% and 97.52% for chlorpyrifos and phoxim, respectively. UV/TiO2 (200 mg/100 mL, 60 min) achieved 57.31% removal of chlorpyrifos and 98.63% removal of phoxim; because TiO2-dark-adsorption controls were not included in this study, these values reflect combined adsorption and reactive oxygen species-mediated processes rather than photocatalysis specifically. Lactiplantibacillus plantarum CICC20261 achieved the greatest LAB-mediated reduction (49.61% chlorpyrifos; 43.28% phoxim) while maintaining robust viability under pesticide exposure (7.79 ± 0.51 log CFU/mL after 24 h under chlorpyrifos; 7.40 ± 0.84 log CFU/mL under phoxim), compared with 9.23 ± 0.42 log CFU/mL in the pesticide-free control at 24 h. Conclusion: Under the specific, non-equivalent reference conditions used for each method (Section 3.3), UV/TiO2 numerically achieved the highest phoxim removal and a moderate chlorpyrifos removal, while sonication was highly effective for phoxim specifically. Together, sonication and LAB fermentation offer rapid, complementary non-thermal approaches to pesticide reduction. Claims of sustainability, eco-friendliness, or industrial applicability are not yet supported by direct measurements of milk quality, sensory attributes, or (for UV/TiO2) nanoparticle safety; thus, such claims should be regarded as provisional until such data are available. However, as currently configured, UV/TiO2 photocatalysis should be regarded as a proof-of-concept degradation method rather than an immediately deployable process, because the protocol did not include a nanoparticle recovery step (e.g., filtration, centrifugation, or catalyst immobilization) or confirmatory quantification of titanium. Residual nano-TiO2 in treated milk therefore represents an unresolved food-safety consideration that requires evaluation before industrial adoption.
Background: Flour is a globally consumed staple food, making its quality and safety crucial for public health. However, the limitations of conventional detection methods and the poor suitability of existing spectral interval selection techniques have constrained the accurate classification of flour adulteration. To address these challenges, this study presents a near-infrared spectroscopy-based approach combined with intelligent spectral interval selection for identifying mixed flour adulteration. Methods: Three hybrid intelligent optimization algorithms were developed: genetic simulated annealing (GSA), genetic particle swarm optimization (GPSO), and simulated annealing particle swarm optimization (SAPSO). These algorithms were integrated with interval partial least squares (iPLS) to develop GSA-iPLS, GPSO-iPLS, and SAPSO-iPLS feature interval selection methods. Highly correlated spectral intervals were selected using the cross-validation classification accuracy of partial least squares discriminant analysis (PLSDA) as the objective function. PLSDA and support vector machine (SVM) classification models were constructed using the selected intervals. Results: All three methods effectively reduced spectral dimensionality and enhanced model performance. Among them, the GSA-iPLS-based PLSDA model demonstrated the best linear classification performance on the test set, achieving an accuracy and F1 score of 94.61% on the test set and an accuracy of 92.26% with an F1 score of 92.84% on the independent validation set. In contrast, the GPSO-iPLS-based SVM model exhibited the highest nonlinear classification performance, with an accuracy and F1 score of 100% on both the test and independent validation sets, respectively. Conclusions: The proposed hybrid intelligent spectral interval selection methods significantly enhance the predictive performance and robustness of flour adulteration detection models. These findings provide a valuable technical framework and theoretical basis for assessing flour quality and safety testing.
Background: The Maillard reaction is responsible for color and flavor development in baked goods and has been proposed as a potential mechanism for heavy metal sequestration due to the chelating capacity of melanoidins. Therefore, this study aimed to investigate the influence of lead (II) ions on the Maillard reaction under simulated bread-making conditions. Methods: A glucose–lysine model system (pH 6.5) was heated and maintained at 100 °C for 60 minutes in the presence or absence of 0.5 mg/L Pb2+. Browning development was monitored by measuring absorbance at 450 nm. Data were analyzed statistically using two-way analysis of variance (ANOVA) followed by Tukey’s post hoc test. Results: Lead ions significantly inhibited browning intensity at all time points, reducing absorbance by 66–76% relative to controls (p < 0.01). Time-dependent browning was observed only in control samples, whereas Pb2+-treated systems showed no significant progression. Conclusion: Pb2+ strongly suppresses the Maillard reaction, likely by sequestering lysine or masking reactive carbonyl groups, thereby preventing early-stage Schiff base formation. Although partial metal binding may occur, the substantial loss of sensory attributes limits the feasibility of Maillard-based lead decontamination in flour systems.
Background: Overuse of antibiotics and chemical preservatives accelerates the emergence of drug-resistant bacteria and threatens food safety. Thyme essential oil (TEO) is a promising natural alternative; however, the application of TEO in food systems and the antibacterial mechanism underlying its effects require further elucidation. Objective: Thus, this study aimed to investigate the antibacterial activity and mode of action of TEO against foodborne bacteria and to evaluate its preservative effects on refrigerated pork. Methods: Minimum inhibitory concentrations (MICs) were determined. Membrane integrity was assessed by Propidium iodide (PI) staining under fluorescence microscopy, and DNA binding was analyzed by gel retardation assay. Pork samples were treated with TEO and stored at 4 °C. Microbial growth, bacterial community diversity and structure, pH, drip loss, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), tissue morphology, and sensory quality were monitored during storage. Results: TEO exhibited MICs of 0.5–2.5 mg/mL, disrupted bacterial membranes, and showed potential interaction with DNA. TEO also demonstrated clear antioxidant capacity. In refrigerated pork, TEO moderately inhibited microbial growth, enriched bacterial community diversity, influenced microbial structure, maintained lower pH and drip loss, reduced TVB-N and TBARS values, preserved tissue integrity, and improved sensory scores throughout storage. Conclusions: TEO exerts antibacterial effects and effectively preserves pork quality by modulating the microbial ecosystem and retarding oxidative spoilage. These findings support its application as a natural and effective food preservative.
Background: This study aimed to determine the prevalence and phenotypic and genotypic characteristics of Enterococcus faecalis strains in traditionally produced cheeses in Ankara, Türkiye. Methods: Enterococcal isolates from cheese samples were identified using phenotypic and molecular methods. Given the public health relevance of E. faecalis, antimicrobial resistance testing was conducted on 33 isolates using a panel of commonly used antibiotics representing a broad range of clinically relevant classes. Antimicrobial resistance of E. faecalis isolates was evaluated using the disk diffusion method following standard guidelines. Results: A total of 98 probable enterococcal isolates were obtained from 108 cheese samples and identified phenotypically and molecularly. E. faecium was the most prevalent species (63.27%), followed by E. faecalis (33.67%) and E. lactis (3.06%), with the predominance of E. faecium being statistically significant (p < 0.05). High resistance rates were observed to rifampicin and kanamycin (100%), followed by ciprofloxacin (90.91%), enrofloxacin (84.85%), trimethoprim (78.79%), and ampicillin (60.61%). Moderate resistance was detected to several β-lactams and other antibiotic classes, whereas lower resistance frequencies were observed for erythromycin, chloramphenicol, and gentamicin. Notably, all E. faecalis isolates were fully susceptible to vancomycin. Multidrug resistance was common among E. faecalis isolates, with 33.33% of isolates resistant to six or more antibiotics. Resistance patterns differed significantly among antibiotic classes (p < 0.05), indicating a heterogeneous resistance distribution. The Multiple Antibiotic Resistance (MAR) index ranged from 0.166 to 0.333, with a mean of 0.27 ± 0.06, exceeding the threshold for high-risk contamination sources. Conclusions: The high prevalence of multidrug-resistant E. faecalis in traditional cheeses highlights the need for improved hygienic practices during artisanal production, rational antimicrobial use in animal husbandry, and ongoing resistance surveillance to mitigate potential risks to food safety and public health.
