Journal of AOAC International最新文献

Background: Different cooking and processing methods to some extent influence the content of food elements. Karst plateau mountainous regions have a significant geochemical high background of Cd.

Objective: The study aims to explore the differences in health risks associated with different cooking methods for cabbage and provide a theoretical basis for safe production of cabbage in karst areas and reduction of consumption-related risks.

Methods: Three varieties of cabbage [Chi bai er hao (CB), Chun xin huo guo wang (CX), and Qing cui chi bai cai (QC)] and three different cooking methods to cook cabbage according to the cooking habits of local residents (raw, boiled, and fried) were studied for their Cd content. The cabbages were grown in soil dosed with known amounts of Cd.

Results: : Cd content in cabbage significantly increased (P < 0.05) with the increase of exogenous Cd levels. The Cd content of cooked cabbage was significantly lower than that of raw cabbage (P < 0.05). The general rule was raw > stir-fried > boiled. The target hazard quotient (THQ) of cabbage consumption by local residents was found to be QC > CX > CB, and the THQ of different cooking methods was raw > stir-fried > boiled.

Conclusions: Residents of a Karst region should choose vegetables that have a Cd content below the standard limit and adopt reasonable cooking methods to reduce health risks. Compared to raw, the cooking method of boiling is the most effective, followed by stir-frying.

Highlights: This study used common cabbage varieties grown in karst areas to investigate the effects of different cooking methods on cadmium content in cabbage, and to evaluate the health risks of different cooking methods on different consumer groups.

Background: Numerous products manufactured from non-humic sources have flooded the market claiming to be fulvic acids. The challenge is finding an easy method to distinguish between products containing genuine fulvic fractions and those containing adulterants. UV spectrophotometry has been widely used to study the fulvic fraction extracted from humic substances, with multiple metrics derived from UV absorption spectra developed and implemented by researchers.

Objective: Leverage ten indices that are characteristic features of the UV spectra of hydrophobic fulvic acids to differentiate products containing authentic fulvic fractions from those containing adulterants.

Methods: Fulvic fractions were diluted to 5 ppm carbon and UV spectra were obtained. Spectra were normalized and analyzed to calculate 10 different indices. The percent difference between the index values of the product and the corresponding index values for the Suwannee River fulvic acid (SRFA) and Pahokee peat fulvic acid (PPFA) standards were calculated. An equally weighted average for all 10 indices was calculated and a 70% cutoff value was used for the average percent error as a screening tool to distinguish products containing fulvic fractions from adulterants.

Results: Fifty-four test samples were analyzed, with nine samples being analyzed by two different laboratories using the established method. Fourteen of the 25 commercial products studied were found to contain fulvic fractions. Increased metal ion concentration within the investigated range did not impact the average percent error calculated, nor did varying the total organic carbon concentrations of the test portions within the range of 1-10 ppm.

Conclusion: The method investigated could be a suitable screening tool for most commercial products and is capable of accurately distinguishing products that contain fulvic fractions.

Highlights: The method accurately found all 11 fulvic fractions isolated from known humic substances as fulvic, and all 11 test samples prepared from non-humified materials as non-fulvic.

Background: There are several globally recognized methods for preparing laboratory samples. Of these, the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) and Quick Polar Pesticides (QuPPe) methods are commonly used for food laboratory sample preparation. As an alternative, we developed a fractionation method using Fractionation of Milk for Trace Analysis of Contaminats and Residues (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 (LCAs) 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 the fractionation method can process 320 samples with FraMiTrACR within 8 h, an 87% increase in potential compared to QuEChERS and a 71% increase compared to QuPPe.

Conclusion: 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-saving and up to an 84% reduction in labor cost per sample.

Background: The OnSite® Gluten Test Kit is a qualitative immunochromatographic assay designed for the detection of gluten in foods and on environmental surfaces.

Objective: To validate the performance of the OnSite Gluten Test Kit in rice flour, oat flour, spice mix, and bread, and on stainless steel surfaces.

Methods: The kit was assessed for cross-reactivity, interference, detection capability of spiked and incurred gluten, recovery from stainless steel surfaces, lot-to-lot consistency, robustness, and stability.

Results: Testing revealed no cross-reactivity or interference from a panel of gluten-free (GF) food items, or susceptibility to high analyte concentration. Analysis of selected spiked or incurred test materials at various estimated concentrations of gluten supported claimed detection capabilities (CDC) ranging from 5 to 20 mg/kg gluten depending on the aliquot volume and food matrix. The method detected wheat gluten present on stainless steel at a contamination level of 11 µg gluten/100 cm2 (probability of detection [POD] 0.95, confidence interval [CI] 0.76-1.00). Testing results also indicated consistency, robustness, and kit stability. Independent laboratory testing of select food matrixes supported the findings of the candidate laboratory.

Conclusion: The performance of the OnSite Gluten Test Kit was validated on gluten spiked or incurred into rice flour, oat flour, spice mix, and bread, and on stainless steel surfaces.

Highlights: The OnSite Gluten Test Kit offers an easy-to-use assay method to detect gluten in select foods and on stainless steel surfaces. The testing format affords the user flexibility in their choice of gluten detection thresholds.

Background: Ascorbyl palmitate (AP) and ascorbyl stearate (AS), together called ascorbyl esters, are antioxidants that are used as food additives to prolong the shelf-life of foods by protecting against deterioration caused by oxidation.

Objective: This article aimed to develop a simple solvent extraction and LC-MS/MS method for the determination of AP and AS in a broad range of food matrices.

Methods: AP and AS in foods were extracted with methanol containing 0.5% (w/v) L-ascorbic acid and analyzed by liquid chromatography-tandem mass spectrometry in negative electrospray ionization and multiple reaction monitoring (MRM) mode.

Results: The method was able to quantitatively detect AP and AS in different food matrices (canned drink, dessert, frozen fish, herbs, oils, infant formula/formulated products, etc.) with recoveries of AP and AS at 73-113% and 75-113%, respectively, and the corresponding relative standard deviations (RSDs) of 0.3-16.1% and 0.2-13.7%. The limits of quantitation were 0.23 mg/kg for AP and 0.14 mg/kg for AS. Method applicability was also demonstrated by the detection of AP in powdered infant formula purchased from local market.

Conclusions: A simple solvent extraction and LC-MS/MS method was developed, validated, and demonstrated for the quantitative determination of AP and AS in various foods.

Highlights: The validated method based on solvent extraction with LC-MS/MS detection offered a fast and simple method for the analysis of AP and AS in a wide range of foods.

Background: The D3 Array Combined assay (PTM 012201) is a qualitative test for the detection of Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Salmonella species, and a broad range of Shiga toxin-producing Escherichia coli (STEC) serogroups in cannabis matrixes. The test involves extraction of nucleic acids from samples followed by preamplification, Loci polymerase chain reaction (PCR), and subsequent Labeling PCR. The PCR amplification product is then hybridized to a DNA microarray. Detection of bacterial and fungal pathogens is determined by fluorescence.

Objective: The objective of this study was to validate the D3 Array Combined method with an optional enrichment step in dried cannabis flower (delta 9-tetrahydrocannabinol [THC] >0.3%), with the use of the Live/Dead Enrichment (LDE) reagent. The method modification was validated with optional enrichment time points at 0, 2, and 24 h.

Methods: The evaluation followed study designs from the AOAC Microbiology guidelines and AOAC Standard Method Performance Requirements (SMPR®s) 2019.001, 2020.02, and 2020.012. The modified method was compared to SMPR confirmation procedures and an unpaired Aspergillus consensus method. The results were evaluated utilizing a probability of detection (POD) statistical model.

Results: Results showed no statistically significant difference, at the 95% and 90% confidence intervals, between the candidate method presumptive D3 Array Combined positive results and the confirmed cultural positive results at all contamination levels and enrichment time points.

Conclusions: This study provides data that demonstrate the PathogenDx D3 Array Combined is a reliable method for detection of A. flavus, A. fumigatus, A. niger, A. terreus , Salmonella species, and a broad range of STEC serogroups in dried cannabis flower from 0-24 h enrichment, for all these organisms.

Highlights: This highly sensitive method provides results within hours of sample acquisition, compared to PCR or cultural methods where results are obtained in 2-7 days. This method also provides the option of enrichment, providing compliance options for all cannabis testing state regulations.

Background: Typical commercial batches of milbemycin oxime (MO) contain over 25 related substances. Many of these related substance peaks exhibit similar chromatographic properties, often coeluting or being poorly separated under current compendial methods. Therefore, an alternative HPLC method with greater selectivity and resolution for MO and its related substance peaks is highly desirable.

Objective: This study aimed to develop and validate a new stability-indicating HPLC method for adequately separating all peaks of interest in typical commercial batches of MO. Method: The final HPLC method utilizes a gradient elution on a HALO® C18 column (100 mm × 4.6 mm, i.d. 2.7 µm particle size) maintained at 50°C, with a flow rate of 0.5 mL/min. The composition of mobile phase-A (MPA) for the final method is water-acetonitrile-perchloric acid (70 + 30 + 0.06, v/v/v), and the composition of mobile phase-B (MPB) is isopropanol-methanol-1,4 dioxane-perchloric acid (50 + 45 + 5 + 0.06, v/v/v/v). The injection volume of the new method is 6 µL and the detection wavelength is 240 nm.

Results: The new HPLC method demonstrated specificity by adequately separating all potential MO-related substances in stress-degraded MO drug substance. It showed good linearity and accuracy in the range of 0.1 to 120% of the target MO analytical concentration. The LOQ and LOD were determined to be 0.1% and 0.03% of the analytical concentration, respectively. The robustness study found no critical parameters affecting the method's specificity or accuracy.

Conclusions: The new HPLC method offers greater selectivity and resolution compared to compendial methods for the MO drug substance. It is more desirable for batch release and stability studies in both routine and non-routine activities.

Highlights: An exhaustive equivalency study between the new HPLC method and the compendial methods demonstrated that the new method is superior compared to the European Pharmacopoeia (Ph. Eur.) method for analyzing MO bulk drug substance.

Background: Quantitative NMR spectroscopy (qNMR) can be used to determine chemical purity. This applies to the resonating nuclei of all the present chemical species, enabling quantitation of the analyte against chemically non-identical calibrator molecules.

Objective: Validation approaches for determining chemical purity with qNMR are being endorsed by major pharmacopoeias and other standard-setting bodies. In this study, we investigated the purity determination, uncertainty evaluation, and method validation of imazosulfuron using qNMR to gain ISO 17034 accreditation.

Methods: We ensured the NIST traceability of imazosulfuron by calibrating 1,4-BTMSB-d  4 (determining its purity and uncertainty) using NIST PS 1 and then calibrating imazosulfuron using the calibrated 1,4-BTMSB-d  4. Purity and uncertainty determinations were performed using qNMR, as per the proposed revisions to the USP General Chapters <761> and <1761>. Method development and validation were performed as described in these chapters using the principles of Analytical Quality by Design (AQbD).

Results: First, we defined a target measurement uncertainty of ± 2.0% (k = 2) as the Analytical Target Profile (ATP). Next, we established robust operating parameters for qNMR and determined the purity and uncertainty of 1,4-BTMSB-d  4. Subsequently, we determined the purity and uncertainty of imazosulfuron using the calibrated 1,4-BTMSB-d  4 to verify that the qNMR method produced reportable values that met the ATP criteria.

Conclusions: The purity and uncertainty of imazosulfuron were 98.2% ± 1.2% (k = 2), meeting the ATP criteria. We then moved on to the next stage to monitor and ensure that the qNMR method remains properly controlled and satisfy the ATP criteria during routine use. Based on the above, we established a validation scheme that meets the requirements of ISO 17034 by leveraging AQbD considerations.

Highlights: The AQbD principles shift the focus of method validation toward procedure design and development, resulting in more rational design, efficient development, and validation.

Background: As the demand for natural colorants is expected to increase in the future, it is important to analyze pesticide residues to investigate the relationship between exposure and health risks. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) analytical method, which uses small-scale SPE for the cleanup process, is increasingly used in Japan. Since this method has hardly been studied for the analysis of pesticides in natural food colorants, it is necessary to evaluate its performance.

Objective: This study aimed to evaluate the applicability of the modified QuEChERS method for the analysis of neonicotinoid insecticides (NEOs) in beetroot and paprika selected from natural colorants.

Methods: The modified QuEChERS method was evaluated by a recovery study using blank beetroot and paprika powder. The matrix effect (ME) was also evaluated in detail for the analysis by the modified QuEChERS and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). These results were compared with those obtained by Japanese official multiresidue method.

Results: The mean recovery, intraday repeatability, and interday reproducibility for the modified QuEChERS were acceptable according to the validation guideline. The MEs for the modified QuEChERS were not particularly strong for the NEOs in the beetroot and paprika even when the isotopically labeled internal standards were not used.

Conclusions: The evaluation of the modified QuEChERS was successfully tested and demonstrated the suitability of this method for the analysis of NEOs in beetroot and paprika.

Highlight: The modified QuEChERS is not only accurate but is also a fast and environmentally friendly method for analyzing NEOs in beetroot and paprika.

Background: A wide range of foods containing genetically modified organisms (GMOs) are commercially available. To verify the accuracy of GMO labeling, real-time PCR is used to quantify GMO content in raw materials. However, DNA fragmentation during food processing can introduce analytical bias, making it difficult to accurately assess GMO content in processed foods.

Objective: This study aimed to establish a method to accurately evaluate food labeling suitability by inferring the GMO content at the raw material stage from the measurement results of processed foods.

Methods: Model processed foods (heat-treated soybeans) containing GM events were prepared and analyzed using a GMO quantification method incorporating taxon-specific real-time PCR with longer amplicons.

Results: We observed that the calculated GMO content increased with the length of the amplicon used in the taxon-specific PCR assay. This finding indicates that GMO content can be artificially influenced by modifying the amplicon size. When a longer amplicon was deliberately employed, the GMO content calculated for the processed food always exceeded that of the raw material.

Conclusion: The use of longer amplicons in taxon-specific PCR can lead to an overestimation of GMO content at the raw material stage based on the measurements from processed foods. If the overestimated value remains below the labeling threshold, the appropriateness of GMO labeling can still be confirmed. The proposed method offers a simplified and practical approach for use in routine inspections.

Highlights: The developed method enables direct analysis of processed foods to assess GMO labeling appropriateness. It eliminates the need to obtain raw materials or conduct multiple analyses. The approach simplifies GMO quantification in inspection laboratories by reducing procedural complexity.