Semiautomated Method for Niacin and Niacinamide in Food Products: Collaborative Study

1979 ◽  
Vol 62 (5) ◽  
pp. 1027-1030
Author(s):  
David C Egberg
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Food Products ◽  
The Other ◽  
Microbiological Method ◽  
Semiautomated Method

Abstract collaborative study was conducted comparing a semiautomated colorimetric niacin method with a manual colorimetric and a microbiological method for 10 food products. Seven laboratories used the microbiological method, 7 laboratories used the manual colorimetric method, and 6 laboratories used the semiautomated method. The semiautomated method was more repeatable within a laboratory and more reproducible between laboratories than was either of the other methods. The semiautomated method results compared favorably with both the microbiological and manual colorimetric method results.

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.

Semiautomated Method for Riboflavin in Food Products: Collaborative Study

1979 ◽  
Vol 62 (5) ◽  
pp. 1041-1044
Author(s):  
David C Egberg
Keyword(s):  
Collaborative Study ◽  
Food Products ◽  
Manual Method ◽  
Semiautomated Method

Abstract A collaborative study was conducted comparing a semiautomated riboflavin method with a manual riboflavin method for 10 food products. Six laboratories provided results from the semiautomated method and 16 laboratories used the manual technique. The semiautomated method was more repeatable within a laboratory and more reproducible between laboratories than was the manual method. The semiautomated method results compared favorably with the manual method for all 10 products.

Collaborative Study of a Semiautomated Method for the Analysis of Prednisolone and Prednisone Tablets

1977 ◽  
Vol 60 (1) ◽  
pp. 27-31
Author(s):  
James F Brower
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Alcoholic Solution ◽  
Tetramethylammonium Hydroxide ◽  
Assay Method ◽  
Blue Tetrazolium ◽  
Coefficients Of Variation ◽  
The Individual ◽  
Semiautomated Method

Abstract A semiautomated colorimetric method for the determination of prednisolone and prednisone was collaboratively studied by 6 collaborators. In the method, an alcoholic solution of the drug is extracted with chloroform and the extract is reacted with tetramethylammonium hydroxide and blue tetrazolium; the absorbance of the resulting color is read at 525 nm. Collaborators were supplied with 4 composites of tablets of different dosage levels, 2 containing prednisolone and 2 containing prednisone. Results agreed with those obtained by the author using the CSP total steroid assay method. The coefficients of variation of the individual collaborator’s results for prednisolone and prednisone ranged from 0.54 to 2.38 and from 0.34 to 2.19%, respectively. This method has been adopted as official first action.

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.

Collaborative Study on Assay of Sulfur Dioxide in Dried Fruit

1965 ◽  
Vol 48 (4) ◽  
pp. 796-801
Author(s):  
F S Nury ◽  
H R Bolin
Keyword(s):  
Sulfur Dioxide ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Dried Fruits ◽  
Dried Fruit ◽  
Test Materials ◽  
Colorimetric Procedure ◽  
Satisfactory Recovery

Abstract Sulfur dioxide analysis by official (Monier-Williams) methods was compared with a new colorimetric procedure for dried fruits. Dried peaches, pears, apples and golden raisins were the test materials. The colorimetric method was found to be neither more nor less variable than two official methods except in analysis of dried pears, took less time and was easier to perform than the official methods, and yielded satisfactory recovery of sulfur dioxide.

scholarly journals An Examination of Consumer Willingness to Pay for Local Products

2015 ◽  
Vol 44 (3) ◽  
pp. 253-274 ◽  
Author(s):  
Aaron Adalja ◽  
James Hanson ◽  
Charles Towe ◽  
Elina Tselepidakis
Keyword(s):  
Willingness To Pay ◽  
Conjoint Analysis ◽  
Random Sample ◽  
Local Food ◽  
Food Products ◽  
The Other ◽  
Local Production

We use data from hypothetical and nonhypothetical choice-based conjoint analysis to estimate willingness to pay for local food products. The survey was administered to three groups: consumers from a buying club with experience with local and grass-fed production markets, a random sample of Maryland residents, and shoppers at a nonspecialty Maryland supermarket. We find that random-sample and supermarket shoppers are willing to pay a premium for local products but view local and grass-fed production as substitutes. Conversely, buying-club members are less willing to pay for local production than the other groups but do not conflate local and grass-fed production.

Interpretation of 25-OH-D3, NEFA, and calcium correlations among cow and calf pairs

2025 ◽  
Vol 77 (04) ◽  
pp. 6511-2025
Author(s):  
SONGUL ERDOGAN ◽  
KEREM URAL ◽  
HASAN ERDOGAN ◽  
DENIZ ALIC URAL ◽  
MEHMET GULTEKIN ◽  
...  
Keyword(s):  
Energy Balance ◽  
Vitamin D3 ◽  
Colorimetric Method ◽  
Negative Energy ◽  
The Other ◽  
Negative Energy Balance ◽  
Test Results ◽  
Blood Samples ◽  
Other Hand ◽  
Cow Calf

In the present study, the aim was to determine alteration of NEFA, calcium and vitamin D3 levels in cow and calf pairs at parturition as well as correlation between each parameter levels. For this purpose, a cow-side device employing the enzymatic colorimetric method was used for measurement of NEFA and calcium levels. On the other hand, serum 25(OH)D3 analysis was performed using the fluorescence immunochromatographic method at the laboratory in the Faculty. Blood samples were taken from Vena jugularis of 15 Simmental cow and calf pairs immediately after parturition and placed in serum and heparinized tubes. In cow and calf pairs, concentration of vitamin D3 (15.6-120 and 31.8-120 ng/mL, respectively), NEFA (0.12-1.2 and 0.09-0.8 mmol/L, respectively) and calcium (1.8 ± 0.9 and 2.2 ± 0.6 mmol/L, respectively) were determined. There was no significant correlation between NEFA, Ca, and vitamin D3 in cows and calf pairs. Taking into account several co-factors that influenced test results, which could not easily be excluded, further studies may be warranted with larger cow-calf pair populations. In conclusion, vitamin D3 concentration in calves is not affected by the negative energy balance of dams in the parturition period.

Effects of Long-Chain Non-Coding Ribonucleic Acid Hox Tran Antisense RNA on Proliferation and Migration of Epithelial Cells of Cataract Lens

2021 ◽  
Vol 11 (12) ◽  
pp. 2329-2336
Author(s):  
Qiang Zeng ◽  
Yiting Luo
Keyword(s):  
Epithelial Cells ◽  
Ribonucleic Acid ◽  
Transforming Growth Factor ◽  
Colorimetric Method ◽  
The Other ◽  
Human Lens ◽  
And Migration ◽  
Long Chain ◽  
Proliferation And Migration ◽  
E Cadherin

In order to explore effects of long-chain non-coding ribonucleic acid (RNA) HOTAIR on proliferation and migration of human lens epithelial cells, SRA01/04 cells were selected as the research strain in this study and divided into S1 group (no HOTAIR transfection), S2 group (siHOTAIR transfection), S3 group (siHOTAIR+10 ng/mL TGF-β2), and S4 group (no HOTAIR transfection+10 ng/mL TGF-β2) according to the presence or absence of transforming growth factor (TGF)-β2 and silent HOTAIR treatment. 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) colorimetric method was applied to detect cell proliferation.Western blot was used for detection of E-cadherin, zonula occluden-1 (ZO-1), Vimentin, α-smooth muscle actin (SMA), Snail, Slug, zinc finger E-box binding homeobox 1 (ZEB1), and Smad-2 expressions. Results showed that the number of transmembrane cells in S4 group was higher markedly than that of the other groups, but that of S2 group dropped steeply compared with the other groups (P <0.05); E-cadherin (2.59±0.58) and ZO-1 (1.95±0.56) of S2 group increased hugely compared with the other groups, while Vimentin (0.57±0.14) and α-SMA (0.64±0.28) decreased sharply compared with the other groups (P < 0.05); Snail (2.51±0.59), Slug (2.11±0.47), and ZEB1 (2.83±0.53) of S4 group rose obviously compared with the other groups, but the above of S2 group reduced hugely compared with the other groups (P < 0.05); pSmad-2 and pSmad-3 of S4 group elevated greatly compared with the other groups, and those of S2 group reduced hugely compared with the other groups (P < 0.05). In conclusion, HOTAIR high expression could promote TGF-β2-induced SRA01/04 cell proliferation, migration, invasion, and epithelial-mesenchymal trans-differentiation, which was related to TGF-β/Smad signaling pathway.

Collaborative Study Using a ZDBT Colorimetric Method for the Determination of Copper in Alcoholic Products

1967 ◽  
Vol 50 (2) ◽  
pp. 334-338
Author(s):  
Duane H Strunk ◽  
A A Andreasen
Keyword(s):  
Sulfuric Acid ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Good Precision ◽  
Determination Of Copper

Abstract Results are given on a collaborative study in which a zinc dibenzyldithiocarbamate (ZDBT) colorimetric method is used to measure copper in alcoholic products such as high wine, spirits, gin, whisky, brandy, rum, and wine. In this method, the sample is made ca 0.SN with sulfuric acid, and carbon tetrachloride containing 0.2% ZDBT is added. The colored copper-ZDBT complex is extracted in the carbon tetrachloride and measured at 438 mμ against a similar carbon tetrachloride extract of a blank. Data show good precision, and it is recommended that the ZDBT method be adopted as official, first action.

Collaborative Study of a Semiautomated Fluorometric Method for the Determination of Reserpine in Tablets

1976 ◽  
Vol 59 (2) ◽  
pp. 289-292
Author(s):  
Mary A Kreienbaum
Keyword(s):  
Vanadium Pentoxide ◽  
Collaborative Study ◽  
Dosage Level ◽  
Fluorometric Method ◽  
Coefficients Of Variation ◽  
Semiautomated Method

Abstract A semiautomated fluorometric method for the determination of resperpine in tablets was collaboratively studied by 7 laboratories. The method is a modification of the semiautomated method of Urbányi and Stober, which involves formation of a fluorogen with vanadium pentoxide. Collaborators were supplied with 3 composites, each from a different dosage level of commercial tablets. The results obtained agreed well with the AOAC manual fluorometric method; coefficients of variation ranged from 0.45 to 2.70%. The method has been adopted as official first action.

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