Journal of AOAC International最新文献

Background: Aflatoxin B1 (AFB1) is widespread in various kinds of food and poses a serious threat to health when it enters the human body via the food chain.

Objective: This study aimed to establish a rapid and sensitive method for the detection of AFB1 and then combine it with HPLC for the quantitative analysis of AFB1 content.

Method: In this work, hydrothermal and sol-gel methods were employed to prepare aminoated magnetic nanoparticles featuring strong magnetism and excellent dispersion. Magnetic nanoparticles bound with antibodies can specifically capture AFB1 and then be combined with HPLC for the quantitative analysis of AFB1 content. Moreover, the key factors influencing the extraction efficiency, such as buffer type, adsorption time, elution time and volume, were optimized.

Results: The samples were spiked with AFB1 at low, medium, and high concentration levels of 5.0, 10.0, and 20.0 μg/kg, respectively. The established method exhibits good linearity within the range of 0.1-100 µg/kg, and the detection limit is as low as 0.09 µg/kg (S/N = 3). The recoveries in real samples ranged from 79.33% to 111.51%, with all relative standard deviations (RSDs) being less than 11.16% (n = 3 for each level).

Conclusions: In conclusion, a rapid and efficient analytical method for detecting AFB1 in corn, peanut and oat based on functionalized immunomagnetic beads (IMBs) coupled with HPLC-FLD have been successfully developed .The method exhibited excellent sensitivity, featuring a low method detection limit of 0.09 μg/kg, high accuracy, and remarkable precision. In comparison to traditional sample preparation techniques, this IMBs-based approach presents substantial advantages in terms of simplicity, rapidity (completing sample processing within approximately 30 minutes), and cost-effectiveness.

Highlights: The IMBs possess excellent magnetic separation capabilities, which effectively streamline the pre-processing steps.

Background: Bovine lactoferrin (bLF) has been supplemented to a variety of foods, particularly dairy products, to promote human health. Reliable analytical methods are required for accurate quantification of bLF in foods. Isolation of bLF from foods using a heparin column and quantification via HPLC have been reported (heparin method); however, its applicability remains limited.

Objective: To develop a broadly applicable method for determining bLF in dairy products by optimizing the extraction buffer conditions used in the heparin method.

Method: bLF was spiked into different dairy products and extracted using buffers with or without additives, such as urea, sodium chloride, EDTA, and Tween 20. These additives reduced interactions between bLF and dairy components and improved the interaction of bLF to the heparin column, with the buffer pH adjusted to 6.0. The extracted bLF was isolated using a heparin column and quantified via C4 reversed-phase HPLC using an external standard calibration curve.

Results: The optimized extraction buffer improved bLF recovery rates across all tested dairy product matrices.

Conclusions: An improved extraction buffer was developed that enhanced the applicability of bLF quantification using the heparin method. This optimized extraction buffer enabled reliable recovery of bLF from diverse and complex dairy product matrices.

Highlight: The optimized extraction buffer significantly improves the recovery and quantification of bLF in various dairy products, providing a versatile solution for accurate bLF analysis.

Background: Psilocybin-containing mushrooms are gaining the attention of the scientific community due to the potential benefits offered by their psychoactive phytochemicals in the treatment of addiction and various mental health conditions. Although there are hundreds of different Psilocybe species, only a handful have been successfully cultivated under indoor controlled conditions and chemically analyzed.

Objective: The goal of this publication is to describe Nammex's ongoing effort to cultivate poorly studied Psilocybe mushroom species and analyze them by high-performance thin-layer chromatography (HPTLC) to identify and quantify important psychoactive compounds.

Methods: Pure mycelium cultures of Psilocybe species were created from spore prints and tissue of mushrooms collected in the wild. From these mycelia, numerous cultivars were developed and then propagated on various substrates, based on nutritionally supplemented cellulosic materials. Using indoor growth chambers under strictly controlled conditions, mushrooms were produced and prepared for analysis.

Results: Six Psilocybe species (P. zapotecorum, P. natalensis, P. azurescens, P. subaeruginosa, P. cyanescens, and P. stuntzii) were successfully cultivated indoors. Species identity was confirmed through analysis of anatomical and microscopic features, as well as by DNA sequencing. HPTLC was successfully used to quantify psilocybin and psilocin and to identify norbaeocystin, baeocystin, and aeruginascin. P. zapotecorum had the highest psilocybin content (1.89%), and P. stuntzii the lowest (0.45%). Preliminary data showed that psilocybin concentrations remained stable across three successive flushes of P. stuntzii. Storage of fresh mushrooms in a -20 °C freezer prior to freeze-drying drastically reduced psilocybin and increased psilocin levels.

Conclusions: This study successfully demonstrated the cultivation and chemical profiling of multiple Psilocybe species under controlled conditions. The detailed HPTLC analysis revealed species-specific differences in psychoactive compound concentrations. Future research will incorporate advanced techniques, such as HPLC and mass spectrometry, to develop a more comprehensive chemical profile of these mushrooms.

Highlights: This study successfully cultivated and chemically analyzed six Psilocybe species, revealing species-specific differences in psychoactive compound concentrations. Storage conditions, differences between stem and cap, and mushroom developmental stage influenced the composition of psychoactive compounds.

Background: The determination of cobalt in water samples (test samples) is crucial, as it is an essential metal; yet, both deficiency and excessive intake may contribute to detrimental effects in humans and animals.

Objective: In this study, a dispersive solid-phase extraction (DSPE) procedure was developed for the determination of trace amounts of cobalt using flame atomic absorption spectrometry (FAAS).

Methods: The Mn3O4-MnOOH nanocomposite was synthesized to be used as a sorbent in the preconcentration of cobalt.

Results: The enhancement in the detection power of the developed analytical method was quantified by the ratio of the detection limits of the Mn3O4-MnOOH-DSPE-FAAS and FAAS systems, revealing a 15-fold increase with the Mn3O4-MnOOH-DSPE-FAAS method.

Conclusion: The recovery results obtained in tap water for the determination of trace amounts of cobalt demonstrated the applicability and accuracy of the developed method.

Highlights: A sensitive analytical strategy was developed for Co. High recovery results were obtained under optimum conditions.

Background: Chlorogenic acid (CGA), a plant-derived phenolic compound, possesses antioxidant, anti-inflammatory, and antimicrobial activities. Accurate quantification is essential due to its therapeutic value and potential toxicity at high doses.

Objective: To develop a rapid, sensitive electrochemical method for CGA detection using spinel-based catalysts with improved conductivity.

Methods: An electrochemical sensing platform was constructed based on a nanocomposite of ZnFe2O4 and boron, sulfur and nitrogen co-doped reduced graphene oxide (BSN-rGO). This hybrid material effectively addresses the intrinsic poor conductivity of spinel oxides by leveraging the synergistic effect between the catalytic activity of ZnFe2O4 and the superior charge transport capability of BSN-rGO. The resulting sensor enabled rapid and quantitative analysis of CGA within two minutes.

Results: The sensor showed a linear detection range of 1 × 10-4 -1 × 10-1 M and a low detection limit of 1 × 10-6 M (S/N = 3). Adding standard recovery reached 97.48% to 100.75%, with RSDs of 1.02% to 2.95%, indicating excellent accuracy and reproducibility in complex matrices.

Conclusion: The proposed method enables rapid and reliable CGA detection in natural products, offering potential for pharmaceutical and food analysis.

Highlights: BSN-rGO integration enhances spinel conductivity and boosts electrochemical sensing performance.

Background: The extensive use of imported commercial Saccharomyces cerevisiae active dry powder preparations has led to a serious homogenization of wine products in China.

Objective: In recent years, there has been growing interest in developing and applying indigenous non-Saccharomyces yeasts to enhance the diversity and distinctive character of wines.

Methods: In this study, a promising indigenous strain, Hanseniaspora uvarum BF-345, previously isolated from local grape juice, was investigated due to its desirable fermentation properties, robust stress tolerance, and high β-glucosidase activity. Response surface methodology (RSM) was employed to optimize the composition of a cryoprotectant formulation for the vacuum freeze-drying of BF-345.

Results: The optimal protectant formulation was determined as follows: 5.63% skim milk powder, 12.89% maltitol, and 7.02% sucrose. Under these conditions, the viability of the freeze-dried cells reached 85.2%, representing a 27.3% increase compared to the pre-optimized formulation.

Conclusion: The prepared active dry yeast complied with the Chinese national standard GB/T 20886.2-2021, and maintained a viability above 70% after 6 months of sealed storage at 4 °C.

Highlights: In micro-vinification trials with Cabernet Sauvignon, the fermentation system inoculated with the freeze-dried powder exhibited higher yeast cell counts and more favorable fermentation kinetics than that inoculated with a liquid seed culture.

Background: The market demand of honey in Bangladesh is raising day by day, but there are concerns about the quality of both farm-fresh and branded honey which are available in the market.

Objectives: This study evaluates the physicochemical and antioxidant properties of farm-fresh and branded honey from the Bangladeshi market.

Methods: The moisture content (MC) and total soluble solid (°Bx) were determined by refractometer; the electrical conductivity (EC) determined by digital conductivity meter; total phenol (TP), total flavonoid (TF) and HMF were measured by Folin-Ciocalteu, aluminum chloride and ultra high performance liquid chromatography-diode array detector (UHPLC-DAD) respectively; and antioxidant capacity was assessed by 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method.

Results: The results revealed that, farm-fresh honey samples exhibited greater content of moisture (>20%), (329.63 ± 1.63 to 986.05 ± 4.81 mg GAE/kg), total flavonoid (95.09 ± 4.99 to 454.73 ± 2.45 mg QE/kg) and antioxidant capacity (IC50 value of DPPH, 47.91 ± 0.19 to 73.66 ± 0.30 mg/mL) compared to branded honey samples (p < 0.05). The HMF amount was varied from 0.82 ± 0.00 to 241.24 ± 2.41 (mg/kg), with forty-two percent (42%) of branded honey samples exceeding both the Bangladesh Standards and Testing Institution (BSTI) and Codex Alimentarius standard limit (80 mg/kg), whereas all farm-fresh honey samples were within the acceptable limit. In multivariate analysis, the principal component (PC1 & PC2) analysis explains 81.30% of the total variance.

Conclusions: Based on compliance with BSTI and Codex HMF limit, farm fresh honey samples meet the acceptable HMF threshold, whereas 42% of branded honey exceeded the standard limit.

Highlights: Analyzed 45 honey samples (farm-fresh, national, international) for physicochemical parameters; Farm-fresh honey exhibited higher moisture, phenolics, flavonoids and antioxidant activity; 42% of branded honeys exceeded HMF standard limits (BSTI and Codex); all farm-fresh samples were within permissible limit.

Background: Pantoprazole is a selective proton pump inhibitor used in its sodium form in pharmaceuticals. Determining its impurities is crucial for drug purity and safety.

Objective: This study aims to develop a faster impurity analysis method than the European Pharmacopoeia (EP) method.

Methods: An Agilent Zorbax SB Phenyl (250 × 4.6 mm, 5.0 µm) column was used for HPLC, and a Restek Ultra Biphenyl (100 × 2.1 mm, 3.0 µm) column for UPLC. A 65:35 (v/v) potassium dihydrogen/dipotassium hydrogen phosphate buffer (pH 7.40)-acetonitrile mixture was the mobile phase. Analyses were performed at 290 nm with flow rates of 1.0 mL/min (HPLC) and 0.25 mL/min (UPLC). Injection volumes were 20 µL (HPLC) and 3.5 µL (UPLC).

Results: The analysis times of the impurity determination methods developed are 15 min shorter for the HPLC method and 30 minutes shorter for the UPLC method compared to the EP method. The developed methods were validated according to ICH guidelines, demonstrating high linearity (R2 > 0.99 over the concentration range of 0.03-2.27 µg/mL), accuracy with mean recoveries ranging from 95.0% to 105.0%, and precision with intra- and inter-day RSD values below 2%. Forced degradation studies under acidic, alkaline, oxidative, thermal, and photolytic conditions confirmed that the methods are stability-indicating, with the ability to separate all major degradation products of pantoprazole sodium.

Conclusion: The method was validated according to International Conference on Harmonisation (ICH) guidelines, and forced degradation studies were also performed. This study presents optimized HPLC and UPLC methods that allow faster impurity analysis and detection of an additional non-compendial impurity, Pantoprazole-N-oxide.

Highlights: As a result of shorter analysis times, a significant cost reduction has also been proven with numerical data. In addition, a performance-cost comparison of two different analytical technologies was made.

Background: Antigenic detection is reliably utilized in rapid diagnostic tests and provides a significant time advantage during pandemics and epidemics. Therefore, the rapid detection of viral infections is of great importance and will remain crucial in the future. The SARS-CoV-2 outbreak, which resulted in severe losses, is the most recent example of this necessity. Among rapid diagnostic tests, lateral flow assays (LFAs) are the most practical and do not require specialized equipment, typically being developed using antibody pairs.

Objective: This study aimed to recombinantly produce a single-chain variable fragment (scFv) specific to the SARS-CoV-2 spike receptor-binding domain (sRBD) and to employ it in the development of lateral flow assays (LFAs) utilizing both antibody and aptamer pairs and an aptamer cocktail.

Methods: Gold nanoparticles were employed as labeling agents, while both the scFv and full length forms of CR3022, along with aptamers specific to the S and N proteins, were utilized in a sandwich assay format.

Results: scFv was produced at a higher concentration and biologically active. It demonstrated effective viral detection in single LFA, Dot Blot Assay (DBA), and multiplex LFA. While single LFA successfully detected only the synthetic target, DBA and multiplex LFA selectively identified the virus in nasopharyngeal and oropharyngeal swab samples.

Conclusion: Findings highlight the differences and effectiveness of using scFv in combination with other capture agents and different assay principles for the development of cost-effective and rapid diagnostic tests.

Highlights: scFvs exhibit variable binding in sandwich assays depending on the combinations employed. When used in combination with an aptamer cocktail, scFvs demonstrate enhanced target binding, which is shown for the first time in this study. The use of multiple testing strategies enables a more effective viral diagnosis.