Stefan Ehling, Joseph J Thompson, Karen J Schimpf, Lawrence H Pacquette, Philip A Haselberger
{"title":"A contemporary look at the precision of modern analytical methods in food analysis and the relevance of the Horwitz equation.","authors":"Stefan Ehling, Joseph J Thompson, Karen J Schimpf, Lawrence H Pacquette, Philip A Haselberger","doi":"10.1093/jaoacint/qsaf026","DOIUrl":"https://doi.org/10.1093/jaoacint/qsaf026","url":null,"abstract":"<p><strong>Background: </strong>The Horwitz equation models an empirically observed relationship between inter-laboratory relative standard deviation RSDR and analyte concentration expressed as a mass fraction. The Horwitz ratio (HorRat) is the ratio of observed RSDR to the corresponding calculated RSDR from the Horwitz equation. The empirical acceptable range is 0.5 to 2.0 for a successful multi-laboratory method validation trial.</p><p><strong>Objective: </strong>This work examines data from multi-laboratory trials on food analyses conducted between 2011-2017 for trends in analytical method precision and the applicability and relevance of the Horwitz model.</p><p><strong>Method: </strong>Data on method precision from 20 multi-laboratory trials consisting of 961 data points were analyzed. The scope was limited to methods employing modern chromatographic and spectroscopic techniques and to well-defined small molecule analytes and elements. Within-laboratory and inter-laboratory precision and their ratio, HorRat, goodness of fit to the Horwitz model, and variation of precision across the analytical range were examined.</p><p><strong>Results: </strong>The variance of inter-laboratory precision is largely (86%) independent of concentration and remains unexplained by the Horwitz equation. Only 52% of all data points fell within the Horwitz band (0.5-2.0), with 46% falling under 0.5, indicating substantially better inter-laboratory precision than predicted by the Horwitz equation at all concentration levels. Near-constant precision was confirmed across the analytical range of methods, even near the limit of quantitation.</p><p><strong>Conclusions: </strong>The analysis of the data in scope demonstrates that the analytical method precision routinely achievable with modern chromatographic and spectroscopic techniques, proper laboratory controls, and training is much better than that predicted by the Horwitz equation. HorRat has lost its relevance as a method performance criterion for judging the success of a multi-laboratory trial.</p><p><strong>Highlights: </strong>Recent data do not follow the Horwitz model. HorRat values <0.5 can be routinely achieved. Method precision is mostly independent of analyte concentration. Method-related factors have greater impact on precision.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143665784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unfolding the nutraceutical potentials of Dendrobium nobile Lindl orchid flowers based on their color variation: a high-resolution mass spectrometry-based untargeted metabolomics study.","authors":"Suman Natta, Nasiruddin Shaikh, Ekatpure Sachin, Amine Kassouf, Nishant Deshmukh, Sankar Prasad Das, Kaushik Banerjee","doi":"10.1093/jaoacint/qsaf025","DOIUrl":"https://doi.org/10.1093/jaoacint/qsaf025","url":null,"abstract":"<p><strong>Background: </strong>Dendrobium nobile is an edible orchid with diverse therapeutic properties. In north-eastern Himalayan states of India, the extract of this flower is consumed by tribal populations for the treatment of diabetes, cancer, and cardiovascular diseases. However, the profile of biologically active compounds in the colored varieties of D. nobile orchid flowers cultivated in the north-eastern Himalayan region is not well-established, necessitating a thorough investigation.</p><p><strong>Objective: </strong>This study aims to establish and compare the metabolite profile of three types of D. nobile flowers (white, light-pink, and dark pink) using liquid chromatography-high resolution mass spectrometry (LC-HRMS).</p><p><strong>Methods: </strong>The homogenized and cryoground flower samples were extracted with aqueous methanol. After LC-MS data acquisition through full-scan (untargeted) and MS/MS (targeted) modes, data processing involved peak alignment, adduct identification, and integration. Results were compared by multivariate statistics using Independent Component Analysis.</p><p><strong>Results: </strong>A total of 73 metabolites was identified, each with mass error of less than 5 ppm for both precursor and fragment ions. From anthocyanin classes, the chemometric analysis revealed 11 distinguishing biomarker metabolites, with variable influence on projection values above 1. Across the test accessions, three compounds, viz. cyanidin-3-diglucoside, delphinidin-3-sophoroside, and delphinidin-3-gentiobioside revealed their discriminatory presence.</p><p><strong>Conclusion: </strong>The study identified the therapeutically important anthocyanins for metabolomic discrimination of three different D. nobile flower accessions. The study will be useful for authenticating D. nobile accessions, derived products, and selecting candidate traits for future breeding programs for varietal improvements.</p><p><strong>Highlights: </strong>This study identified and profiled the bioactive anthocyanin compounds in D. nobile orchid flowers grown in the north-eastern Himalayan region of India, based on color variations using a non-target metabolomics approach.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143665693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to: The Validation of the Wheat Gluten ELISA Kit.","authors":"","doi":"10.1093/jaoacint/qsaf021","DOIUrl":"https://doi.org/10.1093/jaoacint/qsaf021","url":null,"abstract":"","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143665785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hieu M Le, Tianqi Li, Jimena G Villareal, Jie Gao, Yaxi Hu
{"title":"Rapid Authentication of Plant-Based Milk Alternatives by Coupling Portable Raman Spectroscopy with Machine Learning.","authors":"Hieu M Le, Tianqi Li, Jimena G Villareal, Jie Gao, Yaxi Hu","doi":"10.1093/jaoacint/qsaf022","DOIUrl":"https://doi.org/10.1093/jaoacint/qsaf022","url":null,"abstract":"<p><strong>Background: </strong>Plant-based milk alternatives (PBMA) are increasingly popular due to rising lactose intolerance and environmental concerns over traditional dairy products. However, limited efforts have been made to develop rapid authentication methods to verify their biological origin.</p><p><strong>Objective: </strong>In this study, we developed a rapid, on-site analytical method for the authentication and identification of PBMA made by six different plant species utilizing a portable Raman spectrometer coupled with machine learning.</p><p><strong>Methods: </strong>Unprocessed PBMA (i.e., blended raw nut/grain) and processed PBMA that mimic the industrial processing procedures (i.e., filtration and pasteurization) were prepared in lab and subjected to Raman spectral collection without any sample preparation. Three machine learning algorithms [i.e., k-nearest neighbor (KNN), support vector machine (SVM) and random forest (RF)] were tested and compared.</p><p><strong>Results: </strong>RF achieved the best performance in recognizing the plant sources for the unprocessed PBMA, with accuracies of 96.88% and 95.83% in the cross-validation and test set prediction, respectively. Due to small sample size and risk of overfitting, classification models for the biological origin of processed PBMA were constructed by combining Raman spectra of the unprocessed and processed samples. Again, RF models achieved the highest accuracy in identifying the species, i.e., 94.27% in cross-validation and 94.44% in prediction.</p><p><strong>Conclusions: </strong>These results indicated that the portable Raman spectrometer captured the chemical fingerprints that can effectively identify the plant species of different PBMA. Using this non-destructive Raman spectroscopic based method, the overall analysis from sample to answer was completed within 5 min, providing inspection laboratories a rapid and reliable screening tool to ensure the authenticity of the biological origin of PBMA.</p><p><strong>Highlights: </strong>This study presents a novel method for rapid and non-destructive identification of the plant sources of PBMA (both unprocessed and processed) based on the Raman spectroscopic technique and machine learning algorithms.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143617234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Validation of Enzytec™ Liquid D-Glucose/D-Fructose for Enzymatic Determination of D-Glucose and D-Fructose in Selected Foods and Beverages: First Action 2024.04.","authors":"Markus Lacorn, Thomas Hektor","doi":"10.1093/jaoacint/qsaf019","DOIUrl":"https://doi.org/10.1093/jaoacint/qsaf019","url":null,"abstract":"<p><strong>Background: </strong>D-Glucose and D-fructose are present in honey, wine and beer, and in a range of other foodstuffs such as bread, pastries or chocolate. Both sugars can occur as a monosaccharide or in di-, oligo- and polysaccharides.</p><p><strong>Objective: </strong>To validate the performance of the Enzytec™ Liquid D-Glucose/D-Fructose test kit for the determination of D-glucose and D-fructose in food and beverages such as fruit and vegetable juices, soft drinks, wines, and beer.</p><p><strong>Methods: </strong>The method is based on enzymes which are part of a prepackaged kit that contains 3 ready-to-use components. Both sugars are phosphorylated by a hexokinase. Glucose-6-phosphate (G-6-P) and NAD are converted to gluconate-6-phosphate and NADH. NADH is measured at 340 nm. Phosphoglucose isomerase converts fructose-6-phosphate to G-6-P which in turn is converted to gluconate-6-phosphate and NADH.</p><p><strong>Results: </strong>The test is specific to D-glucose and D-fructose and shows no side activities or interferences with the exception of mannose and sulphite that interfere at 5.1 and 1.25 g/L or more, respectively. The measurement range is from 6.1 to 2000 mg/L for D-glucose and 5.6 to 1000 mg/L for D-fructose (100 µL test volume). Trueness was evaluated using NIST SRM 3282 (cranberry juice) and one reference wine. The recoveries ranged from 101 to 102%. Spiking of wine, beer, soft drinks and juices resulted in recoveries between 93 and 105%. Intermediate precision is below 6% for concentrations at 25 mg/L and below 4% for higher concentrations. For automation, three applications with different test volumes and different measurement ranges were validated. Linearity is given from 5.0 up to 10000 mg/L for the sum of both sugars.</p><p><strong>Conclusions: </strong>The method is robust and accurate for manual and automated applications and was approved as AOAC Official Method of Analysis℠.</p><p><strong>Highlights: </strong>The ready-to-use components of the test kit have a shelf of at least 29 months.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143607671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Validation of Enzytec™ Liquid L-Lactic Acid for Enzymatic Determination of L-Lactic Acid in Selected Foods and Beverages: Official Method 2024.07 First Action.","authors":"Markus Lacorn, Thomas Hektor","doi":"10.1093/jaoacint/qsaf020","DOIUrl":"https://doi.org/10.1093/jaoacint/qsaf020","url":null,"abstract":"<p><strong>Background: </strong>Produced naturally by lactic acid bacteria, L-lactic acid is found in many fermented milk products and also in pickled vegetables, cured meats and fish. It serves as a quality parameter in wine, beer, whole egg, whole egg powder, and juices.</p><p><strong>Objective: </strong>To validate the performance of the Enzytec™ Liquid L-Lactic acid for the determination of L-lactic acid in food and beverages such as milk and (fermented) milk products, fermented vegetable products, wines, beer, fruit and vegetable juices, egg and egg powder.</p><p><strong>Methods: </strong>The method is based on enzymes which are part of a prepackaged kit that contains two ready-to-use components which are suitable for automation. L-lactic acids react in the presence of NAD and L-Lactate dehydrogenase to pyruvate and NADH. The NADH formed is equivalent to the amount of L-lactic acid converted.</p><p><strong>Results: </strong>Ascorbic acid, 3-hydroxybutyric acid, and sulfite were found to interfere at concentrations higher than 0.2, 0.05, and 0.05 g/L in the test solution, respectively. Oxaloacetic acid and D-fructose do not interfere at concentrations at or below 0.2 and 10 g/L, respectively. The calculated LOD when using a test volume of 100 µL is 3.8 mg/L and the LOQ is 10 mg/L. The practical upper measurement range is 600 mg/L. Relative intermediate precision was between 3.0 and 7.3% for pineapple juice, sauerkraut juice, wine and liquid egg. Certified Reference Materials (cream cheese and wine) showed recoveries between 100 and 104%. For automation, three applications with different test volumes were validated. Linearity is given from 0.75 up to 3125 mg/L.</p><p><strong>Conclusions: </strong>The method is robust and accurate for manual and automated applications. The method was approved as AOAC Official Method of Analysis℠.</p><p><strong>Highlights: </strong>The components of the test kit have a shelf life of at least 24 months.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143607672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Greg W Curtzwiler, Sarah A Applegate, Mark R Early, Katie M Updegraff, Keith L Vorst
{"title":"Influence of Talc in Polypropylene on Total Fluorine Measurements Used as an Indicator of Per- and Polyfluoroalkyl Substances (PFAS).","authors":"Greg W Curtzwiler, Sarah A Applegate, Mark R Early, Katie M Updegraff, Keith L Vorst","doi":"10.1093/jaoacint/qsae090","DOIUrl":"10.1093/jaoacint/qsae090","url":null,"abstract":"<p><strong>Background: </strong>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 polyfluorinated substances (PFAS) in food packaging materials. Inorganic contributions to the total fluorine signal can result in false positive signals exceeding regulatory limits.</p><p><strong>Objective: </strong>The purpose of this study is to develop a method for determining the contribution of talc inorganic filler to the total fluorine signal.</p><p><strong>Method: </strong>The influence of talc on total fluorine measurements of plastics was evaluated by compounding talc with virgin polypropylene (PP) and 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.</p><p><strong>Results: </strong>A near-infrared spectroscopy (NIR) 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).</p><p><strong>Conclusions: </strong>This study developed a method to predict the 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.</p><p><strong>Highlights: </strong>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.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"137-143"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11879167/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142640254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robert S Salter, Gregory W Durbin, Sherita Li, McGaughren Gilbert, Erin S Crowley, Andrew Deterding, Benjamin Bastin
{"title":"Validation of the Peel Plate Staphylococcus Aureus (SA) Test for Enumeration of S. aureus in Selected Foods and Non-Cultured Dairy Products: AOAC Performance Tested MethodSM 082401.","authors":"Robert S Salter, Gregory W Durbin, Sherita Li, McGaughren Gilbert, Erin S Crowley, Andrew Deterding, Benjamin Bastin","doi":"10.1093/jaoacint/qsae083","DOIUrl":"10.1093/jaoacint/qsae083","url":null,"abstract":"<p><strong>Background: </strong>The microbial testing platform, Peel Plate™, was developed with Baird Parker ingredients for Staphylococcus aureus (SA) specificity. After rehydrating with 1 mL of the diluted food sample, Peel Plate SA is incubated for 24-48 h at 35-37°C and observed for purple colonies.</p><p><strong>Objective: </strong>A validation study was performed to evaluate Peel Plate SA for enumeration of SA in selected foods and non-cultured dairy products for Performance Tested MethodSM (PTM) certification.</p><p><strong>Methods: </strong>Peel Plate SA was evaluated in inclusivity/exclusivity and matrix studies, product consistency and stability studies, and robustness testing. Non-fat dried milk, frozen raw cod fish, corned beef, frozen raw vegetables, potato salad, vegetable soup, frozen unshelled raw shrimp, and baby food (apple, cinnamon, and granola) were evaluated in the matrix studies comparing Peel Plate SA to US and international reference methods. Three levels of contamination along with non-inoculated controls were tested for each matrix.</p><p><strong>Results: </strong>Peel Plate SA detected 49 of 50 SA isolates tested. Of the 38 exclusivity species tested, none were detected. In the matrix studies, the Peel Plate SA results were determined to be equivalent to the reference method results by paired statistical analysis. In an accelerated stability study, the shelf-life of Peel Plate SA was shown to be stable for 12 months. Equivalence was demonstrated between different production lots. Small changes to critical test parameters did not significantly affect the Peel Plate SA results.</p><p><strong>Conclusion: </strong>Peel Plate SA is a ready-to-use method for enumeration of SA in a variety of foods and non-cultured dairy products. As with reference methods, Peel Plate SA colonies should be isolated and confirmed with differentiation tests such as catalase and strong coagulase positive.</p><p><strong>Highlights: </strong>The data were reviewed by the PTM Program and certification was granted for the Peel Plate SA method PTM 082401.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"279-291"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11879224/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142549821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deeksha Bharti, Manjusha Lekshmi, Sanath H Kumar, Binaya Bhusan Nayak
{"title":"Prevalence of Cronobacter spp. in Tropical Seafood From Mumbai, India: Comparative Study of Isolation Media and PCR Detection.","authors":"Deeksha Bharti, Manjusha Lekshmi, Sanath H Kumar, Binaya Bhusan Nayak","doi":"10.1093/jaoacint/qsae094","DOIUrl":"10.1093/jaoacint/qsae094","url":null,"abstract":"<p><strong>Background: </strong>Cronobacter species are opportunistic emerging pathogens associated with diverse foods of plant and animal origin. Considering the diversity of the Cronobacter group of bacteria and their co-existence with closely related Enterobacterales in the aquatic environment, their isolation from fish and shellfish is a challenge.</p><p><strong>Objective: </strong>This study aimed to investigate the incidence of Cronobacter in finfish, shellfish, and dried fish, and to compare nine combinations of enrichment broth-selective isolation media for efficient isolation of Cronobacter spp.</p><p><strong>Methods: </strong>Seventy-five seafood samples collected from five different retail markets were subjected to multiple selective-enrichment methods to isolate Cronobacter, which were presumptively identified by biochemical tests followed by confirmation with genus- and species-specific PCRs.</p><p><strong>Results: </strong>Of 75 seafood samples analyzed, 24 (32%) were positive for Cronobacter spp. The highest incidence was in dried fish (21 samples, 47.72%), followed by 19 (43.18%) fresh finfish and four (9.09%) shellfish samples. Forty-four isolates from these samples were identified as Cronobacter spp. by PCR. Species-specific PCR further categorized these as C. sakazakii (25), C. malonaticus (16), and C. turicensis (1), while two isolates remained unidentified at species level. Enrichment in Cronobacter screening broth or Rappaport Vassiliadis (RV) medium, followed by isolation on chromogenic Cronobacter sakazakii agar was found to be the most effective combination for the isolation of Cronobacter spp. from seafood.</p><p><strong>Conclusions: </strong>Dried fish is an important reservoir of C. sakazakii owing to its desiccation tolerance and absence of competing microbiota in dried fish. Although C. sakazakii is the only known pathogen among Cronobacter spp., improved and specific methods to identify diverse members of this genus are needed.</p><p><strong>Highlights: </strong>Cronobacter sakazakii and C. malonaticus are predominant in tropical seafood. RV with chromogenic CS agar is the most efficient isolation medium for Cronobacter. Specificity of existing PCRs is limited to C. sakazakii and C. malonaticus only. Genus- and species-specific PCRs enhance Cronobacter identification.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"173-179"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142775769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Validation of Enzytec™ Liquid Combi Sucrose/D-Glucose for Enzymatic Determination of Sucrose and D-Glucose in Selected Foods and Beverages: First Action 2024.05.","authors":"Markus Lacorn, Thomas Hektor","doi":"10.1093/jaoacint/qsae100","DOIUrl":"10.1093/jaoacint/qsae100","url":null,"abstract":"<p><strong>Background: </strong>Sucrose is produced in the greatest quantity of all industrially produced organic substances and can be used in almost all processed foods. Glucose is the most abundant monosaccharide and contained in many foodstuffs naturally or added as an ingredient.</p><p><strong>Objective: </strong>To validate the performance of the Enzytec™ Liquid Combi Sucrose/D-Glucose test kit for the determination of sucrose and D-glucose in juices, chocolate, breakfast cereals, ice cream, sweetened condensed milk, wine, beer, and soft drinks.</p><p><strong>Methods: </strong>The kit contains all reagents in a ready-to-use format and is suitable for automation. Sucrose is cleaved by β-fructosidase. The resulting D-glucose from sucrose and glucose originally in the sample are phosphorylated and react in a NADH-generating reaction afterwards. β-Fructosidase is not present in the glucose system. The amount of NADH produced is equivalent to the amounts of sucrose and D-glucose and is measured at 340 nm within 30 min.</p><p><strong>Results: </strong>The linear measurement range for a 100 µL test volume is from 17 to 2500 mg/L sucrose and 4 to 2000 mg/L D-glucose. Trueness was checked by using four Certified Reference Materials (CRM) and resulted in recoveries from 96 to 105%. Spiking of juices, ice cream, sweetened condensed milk, and shandy resulted in recoveries between 98 and 106% for both systems. Intermediate precision was 3% or lower for sucrose and glucose. For automation, three applications with different test volumes were validated. Linearity is given from 3.8 to 9500 mg/L for sucrose and 2.4 up to 10000 mg/L for glucose.</p><p><strong>Conclusion: </strong>The method is robust and accurate for manual and automated applications. The method was approved as an AOAC Official Method of Analysis℠.</p><p><strong>Highlights: </strong>The ready-to-use components of the test kit have a shelf of at least 29 months.</p>","PeriodicalId":94064,"journal":{"name":"Journal of AOAC International","volume":" ","pages":"151-172"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11879208/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142831519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}