scholarly journals Quantification of Wheat, Rye, and Barley Gluten in Oat and Oat Products by ELISA RIDASCREEN® Total Gluten: Collaborative Study, First Action 2018.15

2019 ◽  
Vol 102 (5) ◽  
pp. 1535-1543 ◽  
Author(s):  
Markus Lacorn ◽  
Thomas Weiss ◽  
Paul Wehling ◽  
Mark Arlinghaus ◽  
Katharina Scherf ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Sandwich Elisa ◽  
Collaborative Study ◽  
Measurement Range ◽  
Method Performance ◽  
Performance Requirement ◽  
Collaborative Test ◽  
Study Results ◽  
Hmw Glutenin ◽  
Validation Experiments

Abstract Background: Since its introduction to the analytical community, the R5 method to quantify gluten led to a strong improvement of the situation for the food industry and celiac patients. During recent years, some questions arose on the use of the Codex Alimentarius factor of two to convert from prolamins to gluten, an overestimation of rye and barley, inadequate detection of glutelins, and the inhomogeneous distribution of gluten in oats. These limitations of the R5 method, especially when measuring oat samples, led to AOAC Standard Method Performance Requirement (SMPR®) 2017.021, which was approved by stakeholders in 2017. Objective: We present a collaborative study of a method for the quantitative analysis of wheat, rye, and barley gluten in oat and oat products using a sandwich ELISA that is based on four different monoclonal antibodies including the R5 monoclonal anitbody. Methods: The sandwich ELISA detects intact gliadins and related prolamins from rye and barley, high-molecular-weight (HMW) glutenin subunits (GS) from wheat, HMW secalins from rye, and low-molecular-weight (LMW) GS from wheat. It does not detect D-hordeins from barley. Samples are extracted by Cocktail solution, subsequently followed by 80% ethanol, and analyzed within 50 min. Results: The measurement range is between 5 and 80 mg/kg gluten using a calibrator made out of a gluten extract from four different wheat cultivars. The results of the collaborative test with 19 participating laboratories showed recoveries ranging from 99 to 137% for all three grain sources. Relative reproducibility SDs for samples >10 mg/kg gluten ranged from 10 to 53%. Conclusions: The collaborative study results confirmed that the method is accurate and suitable to measure gluten from all three grain sources and has demonstrated performance on oat matrices, which meets the criteria as specified in SMPR 2017.021. Data from in-house validation experiments are available as Annex B to this publication.

Vitamin C in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography with UV Detection: Collaborative Study, Final Action 2012.22

2017 ◽  
Vol 100 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Esther Campos Giménez ◽  
Frédéric Martin ◽  
K Schimpf ◽  
L Butler Thompson ◽  
D Aoude-Werner ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Vitamin C ◽  
Infant Formula ◽  
Collaborative Study ◽  
Uv Detection ◽  
Method Performance ◽  
Performance Requirement ◽  
Expert Review ◽  
Expert Review Panel ◽  
Repeatability And Reproducibility

Abstract To determine the repeatability and reproducibility values of the AOAC INTERNATIONAL First Action Method 2012.22, Vitamin C in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography with UV Detection, a collaborative study was organized The study was dividedinto two parts: method setup and qualification of participants (part 1) and collaborative study participation (part 2). During part 1, each laboratory was asked to analyze two practice samples using the aforementioned method Laboratories that provided results within a range of expected levels were qualified for part 2, where they analyzed 10 samples in blind duplicates Two of the samples were suspected of spoilage during the test and new cans of the same type of product were analyzed by a subset of laboratories in part 3. The results were compared with Standard Method Performance Requirement (SMPR®) 2012.012 established for vitamin C The precision results were within the requirements stated in the SMPR: 1.4–7.3% and 3.2–11.4% respectively, for repeatability and reproducibility Finally, Horwitz ratio values were all <2 (0.5–1.7). The Expert Review Panel for Stakeholder Panel for Infant Formula and Adult Nutritionals Nutrient Methods determined that the data presented met the SMPR and therefore recommended the method be granted Final Action status.

scholarly journals Evaluating Presence/Absence of Target Microbes in Microbiological Tests

2000 ◽  
Vol 83 (6) ◽  
pp. 1429-1434
Author(s):  
Robert J Blodgett ◽  
Anthony D Hitchins
Keyword(s):  
Performance Studies ◽  
Collaborative Study ◽  
False Negative ◽  
The Other ◽  
Test Results ◽  
Logistic Curve ◽  
Microbiological Method ◽  
Test Portion ◽  
Method Performance ◽  
Data Set

Abstract A typical qualitative microbiological method performance (collaborative) study gathers a data set of responses about a test for the presence or absence of a target microbe. We developed 2 models that estimate false-positive and false-negative rates. One model assumes a constant probability that the tests will indicate the target microbe is present for any positive concentration in the test portion. The other model assumes that this probability follows a logistic curve. Test results from several method performance studies illustrate these estimates.

Determination of Total, Soluble, and Insoluble Dietary Fiber in Foods—Enzymatic-Gravimetric Method, MES-TRIS Buffer: Collaborative Study

1992 ◽  
Vol 75 (3) ◽  
pp. 395-416 ◽  
Author(s):  
Sungsoo C Lee ◽  
Leon Prosky ◽  
Jonathan W De Vries
Keyword(s):  
Dietary Fiber ◽  
Collaborative Study ◽  
Gravimetric Method ◽  
Tris Buffer ◽  
Total Dietary Fiber ◽  
Method Performance ◽  
Insoluble Dietary Fiber ◽  
Heat Stable ◽  
Assay Precision

Abstract A joint AOAC/AACC (American Association of Cereal Chemists) collaborative study of methods for the determination of soluble, insoluble, and total dietary fiber (SDF, IDF, and TDF) was conducted with 11 participating laboratories. The assay Is based on a modification of the AOAC TDF method 985.29 and the SDF/IDF method collaboratively studied recently by AOAC. The principles of the method are the same as those for the AOAC dietary fiber methods 985.29 and 991.42, Including the use of the same 3 enzymes (heat-stable α-amylase, protease, and amyloglucosldase) and similar enzyme Incubation conditions. In the modification, minor changes have been made to reduce analysis time and to Improve assay precision: (1) MES-TRIS buffer replaces phosphate buffer; (2) one pH adjustment step Is eliminated; and (3) total volumes of reaction mixture and filtration are reduced. Eleven collaborators were sent 20 analytical samples (4 cereal and grain products, 3 fruits, and 3 vegetables) for duplicate blind analysis. The SDF, IDF, and TDF content of the foods tested ranged from 0.53 to 7.17, 0.59 to 60.53, and 1.12 to 67.56 g/100 g, respectively. The respective average RSDR values for SDF, IDF, and TDF determinations by direct measurements were 13.1, 5.2, and 4.5%. The TDF values calculated by summing SDF and IDF were in excellent agreement with the TDF values measured independently. The modification did not alter the method performance with regard to mean dietary fiber values, yet It generated lower assay variability compared with the unmodified methods. The method for SDF, IDF, and TDF (by summing SDF and IDF) has been adopted first action by AOAC International.

scholarly journals Indirect and Direct Determination of the Casein Content of Milk by Kjeldahl Nitrogen Analysis: Collaborative Study

1998 ◽  
Vol 81 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming
Keyword(s):  
Standard Deviation ◽  
Nitrogen Content ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Direct Determination ◽  
Raw Milk ◽  
Method Performance ◽  
Relative Standard ◽  
Milk Casein

Abstract The classic method for determination of milk casein is based on precipitation of casein at pH 4.6. Precipitated milk casein is removed by filtration and the nitrogen content of either the precipitate (direct casein method) or filtrate (noncasein nitrogen; NCN) is determined by Kjeldahl analysis. For the indirect casein method, milk total nitrogen (TN; Method 991.20) is also determined and casein is calculated as TN minus NCN. Ten laboratories tested 9 pairs of blind duplicate raw milk materials with a casein range of 2.42- 3.05℅ by both the direct and indirect casein methods. Statistical performance expressed in protein equivalents (nitrogen ⨯ 6.38) with invalid and outlier data removed was as follows: NCN method (wt%), mean = 0.762, sr = 0.010, SR = 0.016, repeatability relative standard deviation (RSDr) = 1.287℅, reproducibility relative standard deviation (RSDR) = 2.146%; indirect casein method (wt℅), mean = 2.585, repeatability = 0.015, reproducibility = 0.022, RSDr = 0.560℅, RSDR = 0.841; direct casein method (wt℅), mean = 2.575, sr = 0.015, sR = 0.025, RSDr = 0.597℅, RSDR = 0.988℅. Method performance was acceptable and comparable to similar Kjeldahl methods for determining nitrogen content of milk (Methods 991.20, 991.21,991.22, 991.23). The direct casein, indirect casein, and noncasein nitrogen methods have been adopted by AOAC INTERNATIONAL.

Composition of and variation in high- and low-molecular weight glutenin subunits, and omega gliadins in Ethiopian tetraploid wheat germplasm

2006 ◽  
Vol 4 (2) ◽  
pp. 134-143 ◽  
Author(s):  
Faris Hailu ◽  
Eva Johansson ◽  
Arnulf Merker ◽  
Getachew Belay ◽  
Harjit-Singh ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Tetraploid Wheat ◽  
Glutenin Subunit ◽  
Low Molecular Weight ◽  
Glutenin Subunits ◽  
Hmw Glutenin Subunits ◽  
Lmw Glutenin Subunits ◽  
Hmw Glutenin ◽  
Omega Gliadins ◽  
High Degree

A collection of 120 Ethiopian tetraploid wheat accessions was analysed for high-molecular weight (HMW) glutenin subunit, low-molecular weight (LMW) glutenin subunit and omega gliadin composition by SDS–PAGE. For the HMW glutenin subunits, a new allelic variant, 2****, was detected which has not been previously described at the Glu-A1 locus. A high proportion of Glu-A1x banding pattern was observed in durum wheat. For the Glu-B1 locus four different banding patterns were detected. Among those HMW glutenin subunits, 7+8 were the most common, while subunits 14+15 and 6+8 were found to be rare. A high degree of variation was evident for the LMW glutenin subunits and D-zone omega gliadins. The association of the composition of the gluten with quality has been discussed. This wide variation can be used in improving the quality of wheat and to widen its genetic base.

Estimation of uncertainty in olfactometry

2009 ◽  
Vol 59 (7) ◽  
pp. 1409-1413 ◽  
Author(s):  
T. Higuchi
Keyword(s):  
Measurement Uncertainty ◽  
Interlaboratory Comparison ◽  
Collaborative Study ◽  
Estimation Procedure ◽  
Measurement Model ◽  
Standard Uncertainty ◽  
Expanded Uncertainty ◽  
Collaborative Test ◽  
Measurement Results ◽  
Estimation Of Uncertainty

Estimation of uncertainty in odour measurement is essential to the interpretation of the measurement results. The fundamental procedure for the estimation of measurement uncertainty comprises the specification of the measurement process, expression of the measurement model and all influences, evaluation of the standard uncertainty of each component, calculation of the combined standard uncertainty, determination of a coverage factor, calculation of the expanded uncertainty and reporting. Collaborative study such as interlaboratory comparison of olfactometry yields performance indicators of the measurement method including repeatability and reproducibility. Therefore, the use of collaborative test results for measurement uncertainty estimation according to ISO/TS 21748 and ISO 20988 is effective and reasonable. Measurement uncertainty of the triangular odour bag method was estimated using interlaboratory comparison data from 2003 to 2007 on the basis of the simplest model of statistical analysis, and the expanded uncertainty of odour index ranged between 3.1 and 6.7. On the basis of the establishment of the estimation procedure for uncertainty, a coherent interpretation method for the measurement results will be proposed and more effective and practical quality control of olfactometry will be available.

RAZOR™ EX Anthrax Air Detection System for Detection of Bacillus anthracis Spores from Aerosol Collection Samples: Collaborative Study

2013 ◽  
Vol 96 (2) ◽  
pp. 392-398 ◽  
Author(s):  
Ted Hadfield ◽  
Valorie Ryan ◽  
Usha K Spaulding ◽  
Kristine M Clemens ◽  
Irene M Ota ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Bacillus Anthracis ◽  
Detection System ◽  
Collaborative Study ◽  
Probability Of Detection ◽  
Data Sets ◽  
Method Performance ◽  
Bacillus Anthracis Spores ◽  
Phosphate Buffered Saline ◽  
Positive Results

Abstract The RAZOR™ EX Anthrax Air Detection System was validated in a collaborative study for the detection of Bacillus anthracis in aerosol collection buffer. Phosphate-buffered saline was charged with 1 mg/mL standardized dust to simulate an authentic aerosol collection sample. The dust-charged buffer was spiked with either B. anthracis Ames at 2000 spores/mL or Bacillus cereus at 20 000 spores/mL. Twelve collaborators participated in the study, with four collaborators at each of three sites. Each collaborator tested 12 replicates of B. anthracis in dust-charged buffer and 12 replicates of B. cereus in dust-charged buffer. All samples sets were randomized and blind-coded. All collaborators produced valid data sets (no collaborators displayed systematic errors) and there was only one invalid data point. After unblinding, the analysis revealed a cross-collaborator probability of detection (CPOD) of 1.00 (144 positive results from 144 replicates, 95% confidence interval 0.975–1.00) for the B. anthracis samples and a CPOD of 0.00 (0 positive results from 143 replicates, 95% confidence interval 0.00–0.0262) for the B. cereus samples. These data meet the requirements of AOAC Standard Method Performance Requirement 2010.003, developed by the Stakeholder Panel on Agent Detection Assays.

scholarly journals Management of sequelae of Kawasaki disease in adults

2018 ◽  
Vol 2017 (3) ◽  
Author(s):  
John B Gordon ◽  
Jane C Burns
Keyword(s):  
Young Adults ◽  
Coronary Artery ◽  
Kawasaki Disease ◽  
Management Strategies ◽  
Collaborative Study ◽  
Calcium Score ◽  
Calcium Deposition ◽  
Coronary Artery Aneurysms ◽  
Study Results ◽  
Growing Population

Background: A growing population of young adults is presenting to cardiologists with late manifestations of Kawasaki disease (KD) that include cardiomyopathy, ischemia, and infarction. The management of these conditions differs in important ways from atherosclerotic heart disease, and yet there is little awareness in the adult cardiology community regarding the special challenges posed by the cardiovascular sequelae of KD. Methods: Observations were made on a population of 140 adult KD patients enrolled in the San Diego Adult KD Collaborative Study. Results: Coronary artery aneurysms resulting from KD in childhood are associated with a high risk of thrombosis and stenosis at the inlet or outlet of the aneurysm. These aneurysms are often highly calcified and may contain a large thrombus burden that may obscure the true size of the aneurysm. Pitfalls in the management of these patients stem largely from failure to recognize the nature of the lesions, which leads to attempts to dilate highly calcified stenotic segments and undersizing of stents. Intravascular ultrasound is helpful in appreciating the true dimensions of the aneurysm, which may be filled with thrombus. Thrombolysis and use of anti-platelet agents followed by systemic anti-coagulation are appropriate management strategies for patients presenting with acute infarction. Bypass grafting with the internal thoracic arteries can be a successful strategy, but care must be taken to avoid competitive flow through the native vessel leading to graft failure. In contrast to the individuals who developed coronary artery aneurysms, young adults who had documented normal echocardiograms associated with their acute KD in childhood and who have no evidence of calcium deposition in the arterial wall as assessed by computed tomography (CT) calcium score appear to have no increased cardiovascular risk in the medium term. Long-term outcomes for adults post-KD in childhood are still being defined. Conclusions: KD poses special management challenges for the adult cardiologist who must recognize the unique features of the cardiovascular lesions in this growing population of patients. 

Collaborative Study of a Chemical Method for Chick Edema Factor in Fats and Fatty Acids

1965 ◽  
Vol 48 (2) ◽  
pp. 433-437
Author(s):  
G R Higginbotham
Keyword(s):  
Fatty Acids ◽  
Chemical Method ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Edema Factor ◽  
Study Results ◽  
Gas Chromatographic Method

Abstract The microcoulometric gas chromatographic method for detection of chick edema factor in fats and fatty acids was suhjected to a second collaborative study. Results were satisfactory, and it is recommended that the method be adopted as official, first action.

scholarly journals Chloride in Milk, Milk Powder, Whey Powder, Infant Formula, and Adult Nutritionals Potentiometric Titration: Collaborative Study, Final Action 2016.03

2019 ◽  
Vol 102 (2) ◽  
pp. 564-569
Author(s):  
Greg Jaudzems ◽  
Fengxia Zhang ◽  
Wu Bolong ◽  
Lei Bao ◽  
Jing Xiao
Keyword(s):  
Infant Formula ◽  
Collaborative Study ◽  
Milk Powder ◽  
Method Performance ◽  
Expert Review ◽  
Performance Requirements ◽  
Expert Review Panel ◽  
Repeatability And Reproducibility ◽  
Set Up ◽  
Single Laboratory

Abstract Background: In September 2015, both AOAC Official Methods 2015.07and 2015.08 single-laboratory validations (SLVs) were reviewed against Standard Method Performance Requirements® (SMPR) 2014.015by the AOAC Stakeholder Panel for Infant Formula andAdult Nutritional (SPIFAN) Expert Review Panel (ERP). Looking at the similarity and uniqueness of the two methods, the authors agreed, as advised by the ERP, to work together to merge the two methods intoone. This combined method was assigned Method 2016.03. Objective: In order to determine the repeatability and reproducibility of the AOAC First Action 2016.03 method, a collaborative study was organized. The study was divided in two parts: (Part 1) method set up and qualification of participants and (Part 2) collaborative study participation. During Part 1, each laboratory was asked to analyze two practice samples. The laboratories that provided results within a range of expected levels were qualified for Part 2, during which they analyzed 25 samples in blind duplicates. Results: The results were compared with SMPR 2014.015 established for chloride. The precision results (repeatability and reproducibility) were within therequirements stated in the SMPR. In general, the precision results (repeatability and reproducibility)were well within the limits stated in the SMPR. Repeatability ranged from 0.4 to 1.9%, in accordance with data obtained during SLV, with reported RSD of repeatability from 0.03 to 1.6%. Meanwhile, reproducibility ranged from 0.6 to 4.0%. Finally, the Horwitz ratio values were all below 1, from 0.2 to 0.9%. Conclusions: The ERP determined that the data presented met the SMPR and accordingly recommended the method to be granted Final Actionstatus. In January 2018, the Official Methods Boardapproved the method as Final Action.

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