Food Analytical Methods最新文献

This study investigated the efficacy of ultra-performance liquid chromatography–isotope dilution–tandem mass spectrometry (UPLC-ID-MS/MS) combined with either liquid–liquid extraction–solid phase extraction (LLE-SPE) or quick, easy, cheap, effective, rugged, and safe (QuEChERS) for the simultaneous determination of six sulfonamides and trimethoprim in beef, pork, and chicken powders. Method performance was comparatively assessed based on chromatographic peak intensities, recoveries, matrix effects, detection limits, and measurement uncertainties. Both methodologies generally achieved recoveries close to 100% for all analytes across meat types, indicating high accuracy and reliability. The only exception was trimethoprim in pork samples processed by LLE-SPE. QuEChERS provided superior matrix cleanup and yielded more consistent results across different meat types. The limits of quantification ranged from 5.4 to 9.8 ng/kg, and measurement uncertainties ranged from 1.6% to 8.0% for both methods. These findings demonstrate that both methods are capable of detecting sulfonamide and trimethoprim residues well below regulatory thresholds, with high precision and generally high recovery across various analytes and matrices. By combining the high separation efficiency and sensitivity of UPLC with the accuracy of IDMS, this approach offers a robust tool for routine monitoring and accurate quantification of these veterinary drug residues in meat products, thereby enhancing food safety oversight.

In this study, a rapid and sensitive HPLC-mass spectrometric method was applied for identification and semi-quantification of flavonoids and nonflavonoids in Kratošija wines. Wines were produced by inoculation of two commercial yeasts (Zymaflore^TM Xpure (Laffort) and Lalvin ICV D80 (Lallemand)) in order to study the effect of the yeast on the phenolics profile of wines. The targeted analyses of phenolic compounds have been performed using HPLC with a tandem mass spectrometer in a single reaction monitoring mode (SRM) or fragmentation spectrum mode to determine each individual compound. A total of 26 phenolic compounds, including 13 nonflavonoids (10 phenolic acids and 2 stilbenes and 1 stilbenoid) and 13 flavonoids (6 flavan-3-ols, 3 flavonols, 2 flavones, 1 flavanone, and 1 flavanonol), have been determined. Flavones chrysin and luteolin, flavanone naringenin, flavanonol taxifolin, and stilbenoid ε-viniferin were reported for the first time in Macedonian red wine. The effect of yeast on the phenolic profile of wines was noticed, as a result of the different fermentation rates in accordance to their specifications. Flavan-3-ols were present in a higher content in the wine fermented with Lalvin ICV D80, while wine fermented with Zymaflore^TM Xpure presented higher amounts of all other phenolic compounds.

Homemade alcohol-related deaths are a significant public health issue which is often overlooked. Methanol, which can be produced through fermentation or deliberately added by the brewers to the beverages, has been reported as the leading cause of most deaths around the world. Botswana has not been spared as cases of death following the consumption of homemade alcoholic beverages remain high; unfortunately, most of these deaths have never been investigated for methanol content. We hereby present, for the first time, a study involving the investigation of eight different samples of Botswana homemade alcoholic beverages for methanol content. A brief history of the samples revealed that they were obtained from local brewers around the country as evidence of deaths related to alcohol consumption. A liquid–liquid extraction gas chromatography mass spectrometry method for the detection and quantification of methanol in the homemade alcoholic beverages was optimized for the extraction of methanol using ethyl acetate and validated for accuracy, precision, repeatability, selectivity, linearity, limit of detection, limit of quantification, and stability. The validated method showed good linearity with correlation coefficient (R²) of 0.996. It was found to be precise with %RSD values ≤ 5%. Repeatability was acceptable with %RSD values ≤ 5%. Also, percentage recoveries were within 100% with lower LOD and LOQ values. After successful validation, all eight samples from the Botswana Police were analyzed. Methanol was detected and quantified in five samples being T16, T42, T46, T50 and T55 at concentrations ranging from 0.04 to 1.6% v/v. The non-carcinogenic risk assessment revealed that methanol values in these samples were around the safety level of 1 (0.783–1.57) when using the guidelines of the United States Environmental Protection Agency (USEPA).

This preliminary study aimed to identify and simultaneously quantify four phenolic of gallic acid (GA), scopoletin (SC), rosmarinic acid (RA), and resveratrol (RV) in the fenugreek (Trigonella foenum-graecum) seeds. Ultrasonic-assisted extraction using a dismembrator (20 kHz) was performed using the uncrushed on whole seeds with three green solvents: acetone (ACT), ethanol (EtOH), and water (H₂O). An in-house UHPLC-DAD method was developed, validated, and applied to determine phenolic profiles in 15 seed samples from Egypt, India, Qassim (Saudi Arabia), Yemen, and Iran. Method validation showed high accuracy [GA: 99.77 ± 12.33%, SC: 99.88 ± 7.94%, RA: 100.37 ± 8.02%, RV: 101.39 ± 5.39%] with r² ≥ 0.9998. Relative SD ranged from 3.04–3.90%, LOD from 10.10–13.85 ppm, and LOQ from 30.60–41.97 ppm. Extract yields (1.2–152.9 mg; mean 24.19 ± 33.12 mg, N = 45) ranked: H₂O (622.8 ± 231.4 mg) > ACT (417.8 ± 61.2 mg) > EtOH (48 ± 5.8 mg). Yemen-origin JY1 (152.9 mg), Egypt-origin JE2 (140.3 mg), and Qassim-origin RQ2 (107.3 mg) gave the highest yields. Total phenolics followed SC (2337.0 ppm) > GA (146.2 ppm) > RV (135.4 ppm) > RA (109.7 ppm). Herein, a solvent specific phenolic recovery ranked as: H₂O (2613.3 ± 502.1 ppm) > EtOH (60.99 ± 27.17 ppm) > ACT (53.6 ± 7.41 ppm), with occurrence patterns: H₂O (SC > GA > RA > RV), EtOH (RV > SC > GA), ACT (GA > SC > RV). Pearson’s correlation confirmed a positive relationship between solvent type and phenolic yield, while K-means clustering identified JQ1 (Qassim) and RE1 (Egypt) as rich in multiple phenolics. These findings offer practical insight of solvent-dependent variation in phenolic content, underlining water as the most effective green solvent for maximizing extraction yield and phenolic recovery.

Pectin, a complex polysaccharide known for its gelling, thickening, and stabilizing properties, is an essential ingredient in various industries, including food, pharmaceuticals, and cosmetics. Its functional characteristics are highly dependent on its molecular structure, which can be influenced by extraction and purification methods. This study investigates the impact of different extraction and purification techniques—specifically ultrafiltration (UF) and alcohol precipitation with and without maltodextrin (MD) addition—on the structural and dynamic properties of pectin. To characterize the molecular dynamics and structural heterogeneity of pectin samples, time-domain nuclear magnetic resonance (TD-NMR) methods including solid echo (SE), double-quantum (DQ) build-up experiment, saturation-recovery (SR), and Goldman-Shen (GS) sequences were employed in combination with Fourier-Transform Infrared (FTIR) spectroscopy. The results demonstrated that the molecular composition of pectins is influenced by the choice of extraction and purification methods. MD treatments result in increased solid content and higher averaged spin–lattice relaxation times, indicative of a more rigid and densely packed structure. The addition of maltodextrin not only enhances the dry matter content but also stabilizes the pectin network through cross-linking and reduced water mobility, which is vital for achieving desired textural properties. The Goldman-Shen sequence provided insights into spin diffusion, revealing that treatments involving isopropanol (IPA) and UF modify the structural domains organization of pectin without significantly altering solid content. This suggests an enhancement in molecular order and flexibility. Correlation analysis of T_DQ values with various models (Pake, Abragamian, Gaussian, Polynomial) further elucidates distinct molecular interactions and relaxation behaviors among different pectin samples.

Differences in matrix effects caused by different types of tea in the analysis of pesticide residues via gas chromatography-tandem mass spectrometry (GC–MS/MS) have not been well studied. This study evaluated the matrix effects of 181 pesticides in three types of tea with different fermentation degrees using GC–MS/MS. The median values of the matrix effects of 181 pesticides for green tea, black tea, and dark tea were 179%, 26%, and 197%, respectively. Among these pesticides, 58 exhibit significant differences in their matrix effects across the three tea matrices. A GC–MS/MS method for 181 pesticide residues in tea was validated using the matrix-matched standards prepared from blank tea samples with a fermentation degree consistent with that of the test samples. The results showed that the recoveries for more than 95% of the pesticides ranged from 60 to 120%, with relative standard deviations (RSDs) less than 25%. The limits of quantitation (LOQs) spanned a range from 5 to 50 μg/kg. When applied to the detection of real-world tea samples, this method achieved a significant reduction in detection errors for 9 pesticides by 21.66–100%. It is recommended that the matrix matched standard solutions be prepared from blank tea with the same fermentation degree as the test samples for the analysis of pesticide residues in different types of tea via GC–MS/MS.

Pereskia aculeata Miller, popularly known as ora-pro-nóbis, is a nutritionally valuable Unconventional Food Plant (UFP) with growing interest for agricultural production. However, little is known about how cultivation practices, such as planting density, influence its nutritional composition. This study evaluated the impact of different planting densities on the production of bioactive compounds in two P. aculeata clones (57009 and 58827), cultivated under four densities (1, 8, 16, and 32 plants/m²). The total protein and phenolic contents remained stable across planting densities, with average protein concentrations of 113.09 ± 11.90 mg/g and 130.94 ± 14.79 mg/g of fresh mass in clones 57009 and 58827, respectively. Flavonoid content was significantly higher in clone 57009, with up to 78% more flavonoids than clone 58827 at the lowest planting density. However, flavonoid concentration in clone 57009 decreased by approximately 50% as planting density increased. Clone 58827 showed a 43% increase in carotenoid content at higher densities compared to the lowest density. In contrast, antioxidant activities (ABTS and DPPH), hydrogen peroxide (H₂O₂), and nitric oxide (NO) levels were not significantly affected by planting density. These findings demonstrate the distinct biochemical profiles of P. aculeata clones and highlight how planting density influences the accumulation of specific bioactive compounds.

Helicobacter pylori (H. pylori), a major foodborne pathogen, necessitates rapid and sensitive detection methods to mitigate infection risks. Current gold-standard techniques like real-time PCR are limited by cost, equipment dependency, and impracticality for on-site food safety monitoring. This study introduces a novel single-walled carbon nanotube (SWCNT)-integrated colloidal gold immunochromatographic assay (SWCNT/CGIC) for rapid H. pylori detection in food matrices. Monoclonal antibodies targeting H. pylori GP1 antigen were conjugated to colloidal gold, and the complexes were further optimized with SWCNTs for labeling. The assay’s sensitivity, specificity, and stability were evaluated using artificially contaminated food samples (milk, vegetables and meat), with real-time PCR as the reference method. Cross-reactivity was tested against common foodborne pathogens, and interference resistance was assessed under varying pH, microbial loads, and saliva concentrations.The SWCNT/CGIC assay showed a detection limit of 1 × 10³ copies/mL and high specificity, with no cross-reactivity against other microbes. Results were obtained within 15 min, outperforming conventional methods like real-time PCR (4–6 h) and bacterial culture (3–5 days). The assay was validated with standard (H. pylori ATCC 43504) and clinically isolated (H. pylori SYHP 170611) strains, as well as artificially contaminated food samples including milk, vegetables, and meat. The SWCNT/CGIC assay provides a rapid (< 15 min), cost-effective, and user-friendly alternative for on-site H. pylori detection in food, particularly in resource-limited settings. While less sensitive than PCR at ultra-low bacterial loads, its operational simplicity and portability make it ideal for food safety inspections. This innovation highlights the potential of nanomaterial-enhanced diagnostics in combating foodborne H. pylori transmission.

This study utilizes Caesalpinia sappan L., traditionally valued for its culinary and medicinal uses, to develop a colorimetric indicator solution for monitoring milk spoilage. The indicator provides real-time updates on milk freshness through color changes induced by biochemical alterations during spoilage. The color of the indicator solution transitions distinctly from orange-red to orange to yellow as the pH shifts from 7.00 to 5.50 to 3.50, correlating with progressive stages of spoilage. An orange-red color was observed for the fresh stage, orange color for about to be spoilt, and yellow color for the spoilt stage of milk samples. The colorimetric changes are attributed to the presence of Brazelin in Caesalpinia sappan L. Digital images of the indicator solution treated with milk samples were analyzed using RGB (red, green, and blue) indices, with the green chromatic shift serving as a reliable parameter for quantifying color changes, providing reliable assessment of milk spoilage. Findings of this study highlight a simple, accessible, and accurate method for milk quality monitoring that requires no specialized equipment or trained personnel, making it suitable for food safety practices in resource-limited settings.

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