Journal of AOAC International最新文献

Background: Monitoring labs are a fundamental link in the food safety chain, and regulatory demands in a competitive economy call for analytical methods that are simpler, faster, more rugged, and broader in scope. The QuEChERSER mega-method introduced in 2021 meets these monitoring needs, which includes high sample throughput, automated cleanup of extracts, and fast low-pressure gas chromatography (LPGC).

Objective: The goal of this work was to extend the QuEChERSER method to additional matrices and more analytes using LPGC, including comparison of the analytical performances of two different mass spectrometric (MS) analyzers: triple quadrupole tandem MS/MS and orbital ion trap (orbitrap) high-resolution (HR)MS.

Methods: The QuEChERSER mega-method was validated for 245 pesticides and environmental contaminants in barley grains and hemp pellets using automated instrument top sample preparation (ITSP) coupled with LPGC-MS/MS or LPGC-HRMS (orbitrap).

Results: Targeted MS/MS detection proved to be more sensitive than orbitrap using full data acquisition, leading to lower limits of quantification (LOQs) with more analytes yielding acceptable recoveries (70-120%) and repeatabilities (RSDs <20%). In barley, 89% of the compounds met validation criteria in MS/MS and 74% in HRMS, which in hemp were 81% and 66%, respectively. Qualitatively, orbitrap HRMS yielded 1% false positives compared to 3-4% in MS/MS, but due to the higher LOQs, the rates of false negatives were 14-17% in orbitrap vs. 6-10% in MS/MS for the different matrices.

Conclusion: The QuEChERSER mega-method including ITSP+LPGC coupled with MS/MS or orbitrap analysis is a robust approach for multiple applications. In the comparison, MS/MS outperformed the orbitrap in terms of sensitivity, but the orbitrap advantages of easier method development, greater selectivity, and possibility for nontargeted/retrospective analysis permit even broader expansion of analytical scope in the future.

Highlights: ITSP+LPGC- MS/MS or HRMS (orbitrap) analysis as part of the QuEChERSER mega-method is a useful and efficient way to monitor for contaminants in foods.

Background: HPTLC is a widely used and accepted technique for identification of botanicals. Current best practices involve subjective comparison of HPTLC-generated images between test samples and certified botanical reference materials based on specific bands.

Objective: This research was designed to evaluate the potential of cutting-edge machine vision-based machine learning techniques to automate identification of botanicals using native HPTLC image data.

Method: HPTLC images from Ginger and its closely related species and common adulterants were used to create large, synthetic datasets using a deep conditional generative adversarial network. This synthetic dataset was used to train and validate a deep convolutional neural network capable of automatically identifying new HPTLC image data. Performance of both neural networks was evaluated over time using appropriate loss functions as an indicator of their progress during learning. Validation of the overall system was measured via the accuracy of the learned model when applied to real HPTLC data.

Results: The machine vision system was able to generate realistic synthetic HPTLC images that were successfully used to train a deep convolutional neural network. The resulting learned model achieved high-accuracy identification from HPTLC images corresponding to Ginger and six other related species.

Conclusions: A proof-of-concept HPTLC image-based machine vision system for the identification of botanicals was proven to be feasible and a fully working prototype was validated for several species related to Ginger.

Highlights: This use of an autonomous machine-vision system for botanical identification removed the subjectivity inherent to human-based evaluation. The learned model also accurately evaluated botanical HPTLC images significantly faster than its human counterpart, which could save both time and resources.

Background: There are several globally recognized methods for preparing laboratory samples. Of these, the QuEChERS and QuPPe methods are commonly used for food laboratory sample preparation. As an alternative, we developed the fractionation method using FraMiTrACR.

Objective: We present a life cycle assessment for the QuEChERS-, QuPPe- and FraMiTrACR methods. Our objective was to collect data to evaluate the carbon footprint of each method. However, as the ecological factors alone do not inform suitability of any given method, we also evaluated economic factors.

Methods: Our life cycle assessments followed ISO 14040/44 to determine the carbon footprint of each method. Also, we have analyzed existing data to support our comparison of all three methods.

Results: The mass of consumables and packaging for our FraMiTrACR method was observed to decrease by 45% and 34% from those required for the QuPPe and QuEChERS methods, respectively. Furthermore, we calculated a 43% reduction in carbon footprint when using FraMiTrACR compared to QuPPe and a 31% reduction compared to QuEChERS. In addition, we determined that our method offers time savings >87% and >71% compared to QuEChERS and QuPPe, respectively. The main economic benefit of FraMiTrACR comes from 84% and 70% labor cost savings compared to QuEChERS and QuPPe, respectively. The laboratory using fractionation method can process 320 samples with FraMiTrACR within 8 hours, an 87% increase in potential compared to QuEChERS and a 71% increase compared to QuPPe.

Conclusions: Fractionation using FraMiTrACR is a more sustainable method for analytical sample preparation, offering the same quality of results and far-reaching economic advantages.

Highlights: In comparison, FraMiTrACR uses up to 45% less consumables and packaging by weight and a reduction in kg CO2eq of up to 43%. In addition, the fractionation method offers up to 85% time savings and up to an 84% reduction in labor cost per sample.

Background: Increasing restrictions for chemicals of concern in plastic packaging materials have created an urgent need to accurately detect and quantify these chemicals. Total fluorine measurements have been utilized to screen for highly scrutinized per and poly-fluorinated substances (PFAS) in food packaging materials. Inorganic contributions to the total fluorine signal can result in false positive signals exceeding regulatory limits.

Objective: The purpose of this study is to develop a method for determining the contribution of talc inorganic filler to the total fluorine signal.

Method: The influence of talc on total fluorine measurements of plastics was evaluated by compounding talc with virgin polypropylene (PP) then measuring the total fluorine concentration using oxidative pyrohydrolytic combustion ion chromatography. This study provides a framework to predict the contribution of talc in plastic samples to the total fluorine signal.

Results: A near infrared spectroscopy method was developed by employing the full width half height (FWHH) of the interstitial fluorine characteristic band of talc. The FWHH signal of the processed puck specimens was determined to be linearly increase with the measured total fluorine difference as a function of talc concentration (R2 = 0.9619).

Conclusions: This study developed a method to predict contribution of talc fillers to the total fluorine signal of plastic samples. This method is critical for accurately determining the regulatory compliance of talc filled plastic samples for PFAS using total fluorine.

Highlights: Total fluorine is a common regulatory compliance technique as an indicator of PFAS. Talc is a common plastic filler that contains fluorine as a contaminant. The fluorine in talc contributes to the total fluorine signal, which can falsely elevate the total fluorine signal, potentially resulting in the lack of regulatory compliance. The developed method serves as a framework of how to identify the fluorine contribution of inorganic fillers in plastics.

Background: The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method, Performance Tested Method  SM (PTM) 122302, is a nucleic acid amplification test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica  1,4,[5],12:i:-, in select poultry samples. Results for SE and ST are generated separately.

Objective: The objective of the study was to validate the MDA2-SE/ST method for detection of an additional monophasic variant of ST, S. enterica  1,4,[5],12:-:1,2.

Methods: A single strain of S. enterica  1,4,[5],12:-:1,2 was tested as part of a seven-strain inclusivity/exclusivity test panel. Strains were tested after growth in two enrichment media used in the method, buffered peptone water (BPW) and buffered peptone water-ISO formulation (BPW-ISO), and at two incubation temperatures, 35 ± 2 °C and 41.5 ± 1 °C.

Results: S. enterica  1,4,[5],12:-:1,2 produced positive results in the ST assay and negative results in the SE assay in both enrichment media and at both incubation temperatures. Results for the other six test strains were as expected under all conditions.

Conclusions: The MDA2-SE/ST method can detect the monophasic variant S. enterica  1,4,[5],12:-:1,2 as well as S. enterica ser. Typhimurium and the monophasic variant S. enterica  1,4,[5],12:i:-. The MDA2-SE/ST method maintains inclusiveness for S. enterica ser. Typhimurium despite flagellar antigen variation.

Highlights: The data were reviewed by the AOAC PTM Program and approval was granted for modification of the MDA2-SE/ST method, PTM 122302.

Background: The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method is a rapid, nucleic acid amplification-based test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica  1,4 , [5] , 12: i:-, in select poultry samples. Results for SE and ST are generated separately.

Objective: The objective of the study was to validate the MDA2-SE/ST method for detection of SE and ST in chicken carcass rinse and raw ground chicken (325 g) for Performance Tested Methods  SM (PTM) certification.

Methods: The study consisted of inclusivity/exclusivity testing and independent laboratory testing of chicken carcass rinse and raw ground chicken using inoculated matrixes. Data were analyzed using a paired probability of detection model to determine if differences in the number of positive results obtained with the MDA2-SE/ST and reference methods were significant.

Results: In inclusivity testing, all 50 SE strains produced positive results in the SE assay and negative results in the ST assay. All 53 ST strains (including the monophasic variant) produced positive results in the ST assay and negative results in the SE assay. All 35 exclusivity strains produced negative results in both assays. The exclusivity panel included multiple non-SE group D1  Salmonella serovars, multiple non-ST group B serovars, Salmonella spp. from other somatic groups, and other Enterobacteriaceae. In matrix testing, results for the MDA2-SE/ST and reference methods were in complete agreement for both matrixes.

Conclusions: Results of the validation study showed that the MDA2-SE/ST method is an accurate, specific method for detection of SE and ST in select poultry matrixes.

Highlights: The data were reviewed by the AOAC PTM Program and approval was granted for certification of the Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium method as PTM 122302.

Background: Acesulfame K (E950) and Saccharin Na (E954) are commonly utilized synthetic sweeteners that are added to various processed food products to improve the sweet flavor. It is essential to give priority to environmentally friendly technology while assessing them, as overuse of these sweeteners presents serious health hazards.

Objective: The main aim of this study was to develop an AQbD aided ecofriendly RP-HPLC technique that can detect both Acesulfame K and Saccharin Na simultaneously incorporating green analytical chemistry (GAC) principles and white analytical chemistry (WAC); using ultrasound-assisted extraction (UAE) technique on commercial food samples.

Method: The usage of ethanol was in accordance with eco-friendly ideals due to its ease of use, speed, and lack of environmental impact. Rotatable central composite designs (rCCD) was used for method optimization and a mobile phase consisting of a 50:50 (v/v) mixture of ethanol and 1% aqueous acetic acid (v/v), the separation was carried out on a Zorbax column (SB-C18, 150 × 4.6 mm, 5 µm) with a flow rate of 1 ml/min and a detection wavelength of 217 nm.

Results: Acesulfame K had retention duration of 1.134 minutes and Saccharin Na of 2.134 minutes. Acesulfame K and Saccharin Na recovery rates varied among different commercially available food samples, ranging from 65-102% and 75-101%, respectively.

Conclusion: At the defined operating point, the developed procedure displays conformity with the previously defined requirements for linearity, accuracy, sensitivity, and repeatability. The most accurate assessments of greenness were produced by the GAPI, AES, and AGREE tools. Results from the Red-Green-Blue 12 (RGB 12) algorithm for whiteness and BAGI for blueness indicate that the method is very practical, cost-effective, and environmentally friendly.

Highlights: The results of this study could pave the way for more eco-friendly and effective AQbD methods to be used in the future for evaluating various sweeteners using green solvents.

Background: Burkholderia gladioli pv. cocovenenans is a notable foodborne pathogen that poses a significant risk to food safety. Contaminated food requires distinct classification and treatment procedures for non-pathogenic B. gladioli and its pathogenic subspecies cocovenenans. Hence, establishing a rapid and sensitive detection method to distinguish them is necessary.

Objective: In this study, we aimed to establish a method combining the CRISPR-Cas12a/Cas13a dual system with recombinase aided amplification for rapid, specific and sensitive detection of non-pathogenic B. gladioli and pathogenic subspecies cocovenenans in food.

Methods: First, a RAA-CRISPR-Cas12a/Cas13a method was developed and its feasibility was assessed. Next, specificity was analyzed using 23 strains of B. gladioli and 5 non-target strains. Following this, sensitivity was evaluated by preparing gradient dilutions of B. gladioli pv. cocovenenans bacterial solutions. At last, real food test samples, including fresh noodles and tremella artificially contaminated with B. gladioli pv. cocovenenans, were utilized for method validation and sensitivity comparison.

Results: The established RAA-CRISPR-Cas12a/Cas13a method exhibited high specificity and achieved 100% accuracy in detecting species B. gladioli and its subspecies cocovenenans. This rapid method could be finished within 45 min with a detection limit of 10° CFU/mL for bacterial concentration. Additionally, it achieved detection limits of 102 CFU/g for fresh noodles and 103 CFU/g for tremella.

Conclusions: The rapid RAA-CRISPR-Cas12a/Cas13a method demonstrated high specificity and sensitivity in detecting and disgusting species B. gladioli and subspecies cocovenenans in both food test samples and post-cultivation colonies.

Highlights: The RAA-CRISPR-Cas12a/Cas13a method presented in this study offers a novel molecular approach for the rapid, accurate and sensitive detection of B. gladioli and its subspecies cocovenenans in foods.

Background: The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method is a nucleic acid amplification test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica  1,4,[5],12:i:-, in select poultry samples. Results for SE and ST are generated separately. The method was previously validated for testing of chicken carcass rinse and raw ground chicken (325 g).

Objective: The objective of the study was to validate the MDA2-SE/ST method for detection of SE and ST in cooked breaded chicken and raw ground chicken (25 g) as a Level 2 modification for Performance Tested Methods  SM certification.

Methods: Inclusivity/exclusivity testing and independent laboratory testing of cooked breaded chicken and raw ground chicken (25 g) were conducted.

Results: In inclusivity testing with BPW-ISO broth at 41.5 °C, all 50 SE strains produced positive results in the SE assay and negative results in the ST assay. All 53 ST strains (including the monophasic variant) produced positive results in the ST assay and negative results in the SE assay. All 35 exclusivity strains produced negative results in both assays. The exclusivity panel included multiple non-SE group D1  Salmonella serovars, multiple non-ST group B serovars, Salmonella spp. from other somatic groups, and other Enterobacteriaceae. In matrix testing, there were no significant differences in the number of positive results obtained with the MDA2-SE/ST and reference methods by probability of detection analysis at the 95% confidence level.

Conclusions: Results of the matrix extension study showed that the MDA2-SE/ST method is an accurate method for detection of SE and ST in cooked breaded chicken and raw ground chicken (25 g).

Highlights: Validation of the MDA2-SE/ST method for two additional matrixes provides users with additional capability for specific detection of SE and ST in poultry products.

Background: The Mettler-Toledo 7000RMS analyzer is a bio-fluorescent particle counter (BFPC) used to monitor real-time bioburden results from purified water (PW).

Objective: Validation of the analyzer using 13 microorganisms and a low-intensity, fluorescent, polystyrene bead.

Methods: During the execution of the validation, a laboratory water system that met PW quality standards was connected to the 7000RMS, and a syringe pump was used to introduce various concentrations of microorganisms and fluorescent polystyrene beads to the analyzer. Samples were collected and tested via the traditional membrane filtration (MF) method and the colony-forming unit (CFU) plate count results were compared to the auto-fluorescent unit (AFU) of the 7000RMS analyzer. The validation study was designed to follow the guidance in United States Pharmacopeia (USP) Chapter <1223>, European Pharmacopeia (EP) Chapter 5.1.6, and parenteral drug association (PDA) Technical Report 33. Concepts and strategies were adapted from EP Chapter 2.6.12 Microbiological Examination of Non-Sterile Products: Microbial Enumeration Tests, EP Chapter 10.2, EP Chapter 2.6.1 Sterility, USP Chapter <61> Microbiological Examination of Non-Sterile Products: Microbial Enumeration Tests, USP Chapter <71> Sterility Tests, and Japanese Pharmacopoeia (JP) General Information Chapter G8 Water: Quality Control of Water for Pharmaceutical Use.

Results: All pre-determined validation acceptance criteria for accuracy, specificity, precision, LOD, LOQ, linearity, and range were met.

Conclusions: The 7000RMS demonstrated performance equivalence to the MF method per USP <1223> but characteristically lacked correlation to the CFU.

Highlights: This validation approach highlights the superior capabilities of the 7000RMS when compared against the traditional compendial MF testing method for PW.