Collaborative Study of the Dye Binding Method Applied to Chocolate Milk Drinks, Cultured Buttermilk, and Half-and-Half

1968 ◽  
Vol 51 (4) ◽  
pp. 811-816
Author(s):  
J W Sherbon
Keyword(s):  
Protein Content ◽  
Collaborative Study ◽  
Practical Significance ◽  
Good Precision ◽  
Chocolate Milk ◽  
Preliminary Results ◽  
Collaborative Studies ◽  
Dry Milk ◽  
Dye Binding ◽  
Proper Sampling

Abstract Collaborative studies of the dye binding method for chocolate-flavored milk drinks, cultured buttermilk, and half-and-half were conducted this year; ten samples of each product were tested in quadruplicate in seven laboratories. The precision of the method with these products was essentially the same as that for fluid milk. The withinlaboratory variations were very small and resulted in statistically significant interlaboratory variations; the actual differences were not of practical significance. It is recommended that these three products be accepted for testing for protein content by the dye binding method. Preliminary results on use of the dye binding method for analyzing nonfat dry milk show good precision; however, proper sampling and duplication procedures need to be established, and studies will continue. Studies will also continue on the required accuracies of reagent preparation, pH of buffer, and sample weighings to establish suitable tolerances.

Collaborative Studies of Methods for Butterfat in omogenized and Chocolate Milk

1964 ◽  
Vol 47 (3) ◽  
pp. 573-576
Author(s):  
D J Mitchell
Keyword(s):  
Collaborative Study ◽  
Chocolate Milk ◽  
Collaborative Studies

Abstract The AOAC Roese-Gottlieb and Rapid Detergent (TeSa) methods for the determination of butterfat in pasteurized, homogenized milk and in chocolate milk were compared in a collaborative study. The results by the detergent method on both products were comparable to those by the Roese-Gottlieb method. The Babcock method gave low results on the homogenized milk.

Comparison of the Dye Binding and Kjeldahl Methods for Protein Analysis of Nonfat Dry Milk and Ice Cream

1969 ◽  
Vol 52 (1) ◽  
pp. 138-142
Author(s):  
J W Sherbon ◽  
H A Luke
Keyword(s):  
Protein Content ◽  
Ice Cream ◽  
Protein Analysis ◽  
Direct Analysis ◽  
Sufficient Accuracy ◽  
Coefficients Of Variation ◽  
Dry Milk ◽  
Dye Binding ◽  
Nonfat Dry Milk

Abstract Ten samples of nonfat dry milk and five samples of vanilla ice cream mix were analyzed in quadruplicate in seven laboratories for protein content by the dye binding method. Laboratory and laboratory times sample effects were significant at the 0.5% level but the coefficients of variation were 1% or less. Comparison of average results obtained by dye binding to those obtained by Kjeldahl show the former to have sufficient accuracy. Direct analysis of NFDM was found to give essentially the same results as analysis of the reconstituted product. It is recommended that the dye binding methods for protein in nonfat dry milk and ice cream mix be adopted as official first action.

Dry Rehydratable Films for Enumeration of Coliforms and Aerobic Bacteria in Dairy Products: Collaborative Study

1989 ◽  
Vol 72 (2) ◽  
pp. 312-318
Author(s):  
Michael S Curiale ◽  
Paul Fahey ◽  
Terrance L Fox ◽  
J Sue Mcallister
Keyword(s):  
Dairy Products ◽  
Collaborative Study ◽  
Ice Cream ◽  
Food Products ◽  
Aerobic Bacteria ◽  
Chocolate Milk ◽  
Coliform Count ◽  
Dry Milk ◽  
Better Than ◽  
Dry Film

Abstract A collaborative study was conducted to compare proposed dry-film plating methods, using aerobic count plates and coliform count plates, to standard agar plating methods for quantifying aerobic bacteria and coliforms in dairy products. In this study, 5 food products (chocolate milk, pasteurized cheese, nonfat dry milk, evaporated milk, and vanilla ice cream), selected as representative dairy products, were analyzed by 11 collaborating laboratories. The results indicate that the dry-film plating methods are equivalent to or better than the agar plating methods. The aerobic count and coliform count dry-film plating methods have been adopted official first action.

Collaborative Studies of Methods for Butterfat in Homogenized and Chocolate Milk

1967 ◽  
Vol 50 (3) ◽  
pp. 537-541
Author(s):  
D J Mitchell
Keyword(s):  
Collaborative Study ◽  
Chocolate Milk ◽  
Collaborative Studies ◽  
Significant Difference

Abstract The modified rapid detergent (TeSa), AOAC Roese-Gottlieb, and Babcock methods for determining butterfat were compared in a collaborative study on 8 samples of homogenized milk by 6 laboratories. The modified rapid detergent and Roese- Gottlieb methods were also compared on 4 samples of chocolate milk by the same collaborators. There was a statistically significant difference between the Roese-Gottlieb and detergent methods in 5 laboratories for homogenized milk and in 4 laboratories for chocolate milk. Additional developmental work is necessary before the detergent method can be applied to homogenized and chocolate milk

Collaborative Studies of Methods for Butterfat in Homogenized and Chocolate Milk

1965 ◽  
Vol 48 (4) ◽  
pp. 806-810
Author(s):  
D J Mitchell
Keyword(s):  
Collaborative Study ◽  
Chocolate Milk ◽  
Collaborative Studies

Abstract The AOAC Roese-Gottlieb, Babcock, and rapid detergent (TeSa) methods for the determination of butterfat were compared in a collaborative study on ten samples of homogenized milk by each of five laboratories. The Roese-Gottlieb and rapid detergent methods were also compared on ten samples of chocolate milk by the same collaborators. Each collaborator obtained the samples in his own area. The Babcock method gave low results for homogenized milk as expected. Comparing the TeSa method with the Roese-Gottlieb method, it appears that more developmental work on the rapid detergent method for homogenized milk and chocolate milk is necessary.

Collaborative Study of the Pro-Milk Method for the Determination of Protein in Milk

1975 ◽  
Vol 58 (4) ◽  
pp. 770-772
Author(s):  
John W Sherbon
Keyword(s):  
Protein Content ◽  
Collaborative Study ◽  
Good Precision ◽  
Milk Samples ◽  
Solution Studies ◽  
Dye Solutions

Abstract Seven milk samples and 2 standard dye solutions were analyzed for protein content by the Pro-Milk method by 6 collaborating laboratories. Interlaboratory variations, although small, were significant, probably because of extremely good precision. Blind duplicates (2 sets) did not differ from each other. Tests of dilute dye solutions, involving only the colorimeters, showed interlaboratory variation, which indicates the need to carefully calibrate each instrument. The magnitudes of the variations encountered in the milk and dye solution studies were sufficiently small to allow adoption of the Pro-milk method as official first action.

Enzymatic Method for Determination of (1→3)(1→4)-Beta-D-glucans in Grains and Cereals: Collaborative Study

1993 ◽  
Vol 76 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Lucian C Zygmunt ◽  
Steven D Paisley ◽  
◽  
G Bromley ◽  
G Durany ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Enzymatic Assay ◽  
Good Precision ◽  
Enzymatic Method ◽  
Beta Glucan ◽  
Collaborative Studies ◽  
Relative Standard ◽  
Cereal Samples ◽  
Beta Glucosidase

Abstract The McCleary enzymatic assay for mixed linkage (1→3)(1→4)-beta-D-glucans has been modified to apply to oat and barley fractions and ready-to-eat (RTE) cereals. The proposed method involves lower sample concentrations; stirring the samples; a longer, warmer lichenase digestion; and longer beta-glucosidase digestion. These changes result in higher recovery of beta-glucan. This modification expands on the American Association of Cereal Chemists (AACC) Method 32-22 by the addition of a desugaring procedure, which is necessary for RTE cereals. Results from collaborative studies sponsored by AACC and AOAC demonstrate good precision for an enzymatic assay. The average relative standard deviation for reproducibility (RSDR, a measure of inter laboratory variation) for 20 oat, barley, and cereal samples was 9.7%. The average RSD for repeatability (RSDr, intralaboratory variation) was 5.0%. The enzymatic method has been adopted first action by AOAC International for determination of beta-glucans in oat and barley fractions, and ready-to-eat cereals.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

Determination of mono- and diacylglycerols in edible oils and fats by high performance liquid chromatography and evaporative light scattering detector: Results of collaborative studies and the standardised method

1999 ◽  
Vol 71 (10) ◽  
pp. 1983-1991 ◽  
Author(s):  
D. Berner ◽  
A. Dieffenbacher
Keyword(s):  
Liquid Chromatography ◽  
Light Scattering ◽  
High Performance ◽  
Edible Oils ◽  
Collaborative Study ◽  
Evaporative Light Scattering Detector ◽  
Light Scattering Detection ◽  
Collaborative Studies ◽  
Evaporative Light Scattering

The development, by collaborative study, of standardised method for the determination of mono- and diacylglycerols in vegetable oils and fats is described. The method involves separation of mono- and diacylglycerols by normal phase high-performance liquid-liquid chromatography (HPLC) and evaporative light scattering detection of a solution of oil, fat or a commercial mono- and diacylglycerol preparation in a organic solvent.

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