Homogeneity of Meats Prepared for Analysis with a Commercial Food Processor: Collaborative Study

1989 ◽  
Vol 72 (5) ◽  
pp. 777-783
Author(s):  
Roberta M Beebe ◽  
Eric Lay ◽  
Sylvan Eisenberg
Keyword(s):  
Confidence Intervals ◽  
Collaborative Study ◽  
Performance Standards ◽  
Pork Sausage ◽  
Food Processor ◽  
Upper Limits ◽  
Accredited Laboratory ◽  
Standard Deviations ◽  
Meat Samples ◽  
Food Chopper

Abstract The food processor was evaluated as an alternative to the food chopper and bowl cutter for preparing meat samples for analysis in AOAC procedure 24.001. Samples of 6 meat types—cooked sausage, pork sausage, canned ham, hamburger, water-added ham, and smoked ham—were distributed to 9 laboratories for preparation using a food processor. The resulting 54 samples were sent to a USDA-accredited laboratory for analysis in triplicate for moisture, protein, and fat. Standard deviations and their 95% confidence intervals calculated for the analytical results were compared with USDA Performance Standards. With few exceptions, the upper limits were lower than the Performance Standards and for the exceptions, the intervals included the Performance Standards. By these criteria, the food processor is as effective in preparing homogeneous samples as the preparation procedures used to set the Performance Standards. Collaborators found the processor faster to use and easier to clean than the food chopper. Use of the food processor has received interim approval as an alternative to the food chopper or bowl cutter in AOAC procedure 24.001 for preparing meat samples for analysis.

Sulfuric Acid/Hydrogen Peroxide Digestion and Colorimetric Determination of Phosphorus in Meat and Meat Products: Collaborative Study

1991 ◽  
Vol 74 (1) ◽  
pp. 22-26 ◽  
Author(s):  
David K Christians ◽  
Thomas G Aspelund ◽  
Scott V Brayton ◽  
Larry L Roberts
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Collaborative Study ◽  
Meat Products ◽  
Colorimetric Determination ◽  
Pork Sausage ◽  
Relative Standard ◽  
Significant Difference ◽  
Standard Deviations

Abstract Seven laboratories participated In a collaborative study of a method for determination of phosphorus in meat and meat products. Samples are digested In sulfuric acid and hydrogen peroxide; digestion Is complete In approximately 10 mln. Phosphorus Is determined by colorimetric analysis of a dilute aliquot of the sample digest. The collaborators analyzed 3 sets of blind duplicate samples from each of 6 classes of meat (U.S. Department of Agriculture classifications): smoked ham, water-added ham, canned ham, pork sausage, cooked sausage, and hamburger. The calibration curve was linear over the range of standard solutions prepared (phosphorus levels from 0.05 to 1.00%); levels in the collaborative study samples ranged from 0.10 to 0.30%. Standard deviations for repeatability (sr) and reproducibility (sR) ranged from 0.004 to 0.012 and 0.007 to 0.014, respectively. Corresponding relative standard deviations (RSDr and RSDR, respectively) ranged from 1.70 to 7.28% and 3.50 to 9.87%. Six laboratories analyzed samples by both the proposed method and AOAC method 24.016 (14th Ed.). One laboratory reported results by the proposed method only. Statistical evaluations Indicated no significant difference between the 2 methods. The method has been adopted official first action by AOAC.

Diagnostic Data Evaluation. Part III. Collaborative Study Evaluation: Standard Deviation Considered To Be A Constant

1990 ◽  
Vol 73 (3) ◽  
pp. 411-414
Author(s):  
Anthony J Malanoski
Keyword(s):  
Crude Protein ◽  
Collaborative Study ◽  
Performance Standard ◽  
Evaluation Standard ◽  
Pork Sausage ◽  
Sample Weights ◽  
Study Evaluation ◽  
Analyst Bias ◽  
Kjeldahl Digestion ◽  
Standard Deviations

Abstract The diagnostic evaluation of the crude protein collaborative study Identified possible problems with a standardized Interval for the Kjeldahl digestion, with sample preparation, and with excess sample weights. The standard deviations for the ham and the beef samples cannot be considered to be representative of the method because of these problems. The standard deviations for the frankfurter and the pork sausage samples for all analysts met the performance standard of 0.24. There was no evidence of analyst bias.

Combustion Method for Determination of Crude Protein in Meat and Meat Products: Collaborative Study

1993 ◽  
Vol 76 (4) ◽  
pp. 787-793 ◽  
Author(s):  
Brink Marcia King ◽  
Sebranek Joseph G. ◽  
◽  
C Anthony ◽  
P Coleman ◽  
...  
Keyword(s):  
Crude Protein ◽  
Collaborative Study ◽  
Meat Product ◽  
Meat Products ◽  
Combustion Method ◽  
Relative Standard ◽  
Kjeldahl Method ◽  
Standard Deviations ◽  
Meat Samples

Abstract Twelve laboratories participated in a collaborative study to compare a combustion method with the AOAC mercury catalyst Kjeldahl method (928.08) for the determination of crude protein in meat and meat products. Three different combustion instruments were used; consequently, the combustion method for this study is written in generic terms describing the principle, the apparatus specifications, and the performance requirements needed. Fifteen sample pairs were used for the study; each pair consisted of the same commercial meat product from each of 2 different manufacturers. Protein content of all samples ranged from about 10 to 20%. In addition, nicotinic acid and lysine monohydrochloride were used as standards to assess combustion equipment performance. All laboratories and all instruments performed the combustion method satisfactorily on the basis of results for the standards. For the meat samples, repeatability standard deviations (sr) ranged from 0.11 to 0.40 for the Kjeldahl method and from 0.12 to 0.41 for the combustion method; the repeatability relative standard deviations (RSDr) ranged from 0.82 to 2.41% and from 0.60 to 2.23% for the Kjeldahl and combustion methods, respectively. Reproducibility standard deviations (SR) ranged from 0.20 to 0.49 for the Kjeldahl method and from 0.18 to 0.46 for the combustion method, whereas the reproducibility relative standard deviations (RSDR) ranged from 1.59 to 2.84% for the Kjeldahl method and from 1.32 to 3.35% for the combustion method. Overall grand means were 15.59% protein for the Kjeldahl method and 15.75% protein for the combustion method. The combustion method was adopted first action by AOAC International.

Comparison of Mercury and Copper Based Catalysts in the Kjeldahl Determination of Nitrogen in Meat and Meat Products: Collaborative Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1542-1556 ◽  
Author(s):  
Cindy G Price ◽  
Neil B Webb ◽  
Wertice J Smith ◽  
Harry M Marks ◽  
Aron M Yoffe
Keyword(s):  
Protein Content ◽  
Copper Catalyst ◽  
Collaborative Study ◽  
Meat Products ◽  
Pork Sausage ◽  
Dry Cured Ham ◽  
Kjeldahl Method ◽  
Repeatability Standard Deviation ◽  
Aoac Method ◽  
Standard Deviations

Abstract A copper catalyst for use in AOAC Method 928.08, Nitrogen in Meat, Kjeldahl Method, was subjected to a collaborative study in which it was compared to the standard mercury catalyst. Nine laboratories (including one author’s laboratory) performed blind duplicate determinations of the protein content of 4 samples from each of 6 products (ground beef, canned ham, smoked ham, pork sausage, cooked sausage, and dry cured ham). On the average, protein concentrations obtained with the copper catalyst were lower than those obtained with the mercury catalyst by approximately 1% of the protein content of the meat. For example, with a sample containing 15% protein, the results obtained with mercury would be expected to be 0.15% higher than those obtained with copper. This difference is within the reproducibility standard deviations of the methods. The repeatability standard deviation with copper was on the average approximately 17% larger than that obtained with mercury, but the reproducibility standard deviations for the 2 procedures were not, statistically, significantly different. The Kjeldahl method for nitrogen determination in meat and meat products using copper catalyst has been adopted first action by AOAC INTERNATIONAL.

Enzymatic-Ultraviolet Method for Measuring Lactose in Milk: Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 637-640 ◽  
Author(s):  
David O Biltcliffe ◽  
Dick H Kleyn ◽  
J Richard Trout ◽  
◽  
D Azzara ◽  
...  
Keyword(s):  
Food Industry ◽  
Collaborative Study ◽  
Skim Milk ◽  
Gravimetric Method ◽  
T Test ◽  
Enzymatic Method ◽  
Commercial Laboratory ◽  
Aoac Method ◽  
Standard Deviations

Abstract Collaborators in 8 dairy and food industry laboratories performed one lactose determination on each of 8 unknown samples of milk, lowfat milk, or skim milk, as 3 pairs of blind duplicates. Two known samples were provided to gain experience prior to analysis of the unknown samples. All of the above samples were also analyzed for lactose content by the official AOAC gravimetric method (16.507) by a commercial laboratory. From the overall mean of results on all samples, determinations by the enzymatic method averaged 0.49% lower than by the AOAC method. This difference was significant by the t-test (P = 0.05), which indicated a lack of agreement between the compared methods in determining lactose content. Standard deviations were similar for the 3 sets of blind duplicates which ranged between 3.67 and 4.55% lactose content. F-values revealed that variations between means obtained by laboratories differed significantly as compared with variations within laboratory means. The method has been adopted official first action.

Collaborative Study of a Column Chromatographic Method for Chlorothiazide, Methyclothiazide, and Polythiazide

1973 ◽  
Vol 56 (3) ◽  
pp. 677-680
Author(s):  
F Raymond Fazzari
Keyword(s):  
Acetic Acid ◽  
Spectrophotometric Determination ◽  
Organic Phase ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Standard Deviations ◽  
Column Chromatographic

Abstract Chlorothiazide is eluted from a K2HPO4 column with acetic acid-ether solvent and extracted from the organic phase into HCl for the Spectrophotometric determination. Methyclothiazide and polythiazide are eluted from a NaHCO3 column with CHCl3 and measured directly. The method was collaboratively studied by 10 analysts. The average per cent recovered and standard deviations for preparations of chlorothiazide and methyclothiazide were 100.2±0.67 and 99.8±1.64, respectively. The method for chlorothiazide and methyclothiazide has been adopted as official first action.

Collaborative Study of the Spectrophotometric Determination of Procainamide Hydrochloride

1976 ◽  
Vol 59 (4) ◽  
pp. 807-810
Author(s):  
Jeffrey C Hamm
Keyword(s):  
Sodium Hydroxide ◽  
Acid Medium ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Collaborative Study ◽  
Dosage Forms ◽  
Standard Deviations

Abstract The USP analysis for procainamide HCl is titrimetric and relatively nonspecific, capsule and tablet dyes may interfere, and the method is not applicable to coated tablets. In the spectrophotofluorometric method the sample deteriorates when exposed to a xenon source. In the ultraviolet spectrophotometric method reported here, the sample is dispersed in acid medium, possible interferences are extracted in chloroform, base is added, procainamide is extracted in chloroform, the residue is dissolved in sodium hydroxide, and the compound is measured by absorption at 272 nm and comparison with a standard. Recoveries of standards added to capsule, tablet, and injection composites ranged from 99.3 to 102%. Twelve collaborators reported duplicate assay results for all 3 dosage forms with per cent standard deviations for 5 samples ranging from 1.01 to 1.27%. The method has been adopted as official first action.

Evaluation of Modification of the 3M™ Molecular Detection Assay (MDA) Salmonella Method (2013.09) for the Detection of Salmonella in Selected Foods: Collaborative Study

2014 ◽  
Vol 97 (5) ◽  
pp. 1329-1342 ◽  
Author(s):  
Patrick Bird ◽  
Kiel Fisher ◽  
Megan Boyle ◽  
Travis Huffman ◽  
M Joseph Benzinger ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Molecular Detection ◽  
Collaborative Study ◽  
Ground Beef ◽  
Inoculum Level ◽  
Test Portion ◽  
Low Level ◽  
Dog Food ◽  
Detection Assay ◽  
The U.S

Abstract The 3M™ Molecular Detection Assay (MDA) Salmonella utilizes isothermal amplification of nucleic acid sequences with high specificity, efficiency, rapidity and bioluminescence to detect amplification of Salmonella spp. in food, food-related, and environmental samples after enrichment. A method modification and matrix extension study of the previously approved AOAC Official MethodSM 2013.09 was conducted, and approval of the modification was received on March 20, 2014. Using an unpaired study design in a multilaboratory collaborative study, the 3M MDA Salmonella method was compared to the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) Microbiology Laboratory Guidebook (MLG) 4.05 (2011), Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, and Catfish Products for raw ground beef and the U.S. Food and Drug Administration (FDA)/Bacteriological Analytical Manual (BAM) Chapter 5, Salmonella reference method for wet dog food following the current AOAC guidelines. A total of 20 laboratories participated. For the 3M MDA Salmonella method, raw ground beef was analyzed using 25 g test portions, and wet dog food was analyzed using 375 g test portions. For the reference methods, 25 g test portions of each matrix were analyzed. Each matrix was artificially contaminated with Salmonella at three inoculation levels: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2–2 CFU/test portion), and a high inoculum level (2–5 CFU/test portion). In this study, 1512 unpaired replicate samples were analyzed. Statistical analysis was conducted according to the probability of detection (POD). For the low-level raw ground beef test portions, the following dLPOD (difference between the LPODs of the reference and candidate method) values with 95% confidence intervals were obtained: –0.01 (–0.14, +0.12). For the low-level wet dog food test portions, the following dLPOD with 95% confidence intervals were obtained: –0.04 (–0.16, +0.09). No significant differences were observed in the number of positive samples detected by the 3M MDA Salmonella method versus either the USDA/FSIS-MLG or FDA/BAM methods.

Microbial Receptor Assay for Rapi d Detection and Identification of Seven Families of Antimicrobial Drugs in Milk: Collaborative Study

1988 ◽  
Vol 71 (2) ◽  
pp. 304-316 ◽  
Author(s):  
Stanley E Charm ◽  
Ruey Chi
Keyword(s):  
Binding Sites ◽  
Specific Binding ◽  
Scintillation Counter ◽  
Collaborative Study ◽  
False Negative ◽  
Penicillin G ◽  
Specific Binding Sites ◽  
Receptor Assay ◽  
Relative Standard ◽  
Standard Deviations

Abstract A microbial competitive receptor assay for detecting residues of antibiotic families in milk was studied collaboratively by 13 laboratories. The drugs and levels (ppb) tested in this study i nclude penicillin G, 4.8; cephapirin, 5.0; cloxacillin, 100; tetracycline, 2000; chlortetracycline, 2000; oxytetracycline, 2000; erythromycin, 200; lincomycin, 400; clindamycin, 400; sulfamethazine, 75; sulfamethoxazole, 50; sulfisoxazole, 50; streptomycin, 1000; novobiocin, 50; and chloramphenicol, 800. In this method, microbial cells added to a milk sample provide specific binding sites for which 14C or 3H libeled drug competes with drug residues in the sample. The UC or H binding to the specific binding sites is measured in a scintillation counter and compared with a zero standard milk. If the sample is statistically different from the zero standard, it is positive. The assay takes about 15 min. The binding reaction occurs between the receptor site and the drug functional group, so all members of a drug family are detected. In this case, beta-lactams, tetracyclines, macrolides, aminoglycosides, novobiocin, chloramphenicol, and sulfonamides, including/^-aminobenzoic acid (PABA) and its other analogs, are detectable. The incidence of false negative determinations among samples is about 1%; the incidence of false positives is about 3%. For negative cases, the relative standard deviations for repeatability ranged from 0 to 5% and for reproducibility from 0 to 6%. For positive cases, relative standard deviations ranged from 0 to 13% for repeatability and from 0 to 14% for reproducibility. The method has been adopted official first action.

Quantitative Ultraviolet Determination of Amiben in Dry Granular and Liquid Formulations: Collaborative Study

1970 ◽  
Vol 53 (6) ◽  
pp. 1155-1159
Author(s):  
Joax W Brunstad
Keyword(s):  
Sodium Salt ◽  
Collaborative Study ◽  
Standard Deviations

Abstract Amiben is determined as the sodium salt in 1% NaOH at 297 nm. Prepared materials and technical formulations containing 0-60 μg amiben/ml were analyzed in a collaborative study. Standard deviations for technical samples ranged from 0.05 to 0.45 and for prepared samples from 0.02 to 0.35. The method is recommended for adoption as official first action.

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