Journal ArticleDOI
388. The colorimetric determination of lactic acid in milk and milk products
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TLDR
In this article, a colorimetric determination of lactic acid in milk and unsweetened milk products is described for the color-imaging of protein and lactose in milk.Abstract:
A method is described for the colorimetric determination of lactic acid in milk and unsweetened milk products. The protein and lactose is removed after precipitation with copper sulphate and calcium hydroxide at 45° C, the lactic acid in an aliquot of the filtrate is oxidized to acetaldehyde in sulphuric acid in the presence of copper sulphate, a purple colour is developed with p–hydroxydiphenyl, and the colour intensity is measured in a photoelectric absorptiometer or other suitable instrument.Recoveries of from 96 to 103%, averaging 100%, were obtained when 20–400 mg. lactic acid/100 ml. were added to fresh milk.The proposed method has an advantage over existing methods in the ease and speed with which large numbers of determinations can be carried out simultaneously whilst retaining the essential accuracy.read more
Citations
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High Performance Liquid Chromatographic Determination of Organic Acids in Dairy Products
TL;DR: In this article, a simple isocratic HPLC technique was developed for the quantitative analysis of organic acids in dairy products using an Ammex HPX-87 column at 65°C, 0.0090N H2SO4 mobile phase and UV detection at 220 and 275 nm.
Journal ArticleDOI
Lactate Acid Inhibition of Salmonella Typhimurium in Yogurt
TL;DR: How lactic acid inhibits growth of Salmonella typhimurium in yogurt was determined by microscopic examination not to be due to bacteriolysis and was from the intracellular dissociated moiety of lactic Acid.
Journal ArticleDOI
Bacterial fermentation of cheese whey for production of a ruminant feed supplement rich in curde protein.
TL;DR: A simple and efficient process for the production of a ruminant feed supplement, rich in crude protein, by bacterial fermentation of cheese whey has been developed, and 40 tons of concentrated product were produced fro animal feeding trials, without ever encountering putrefactive spoilage.
Journal ArticleDOI
Lactose, lactic acid and mineral equilibria in Cheddar cheese manufacture
TL;DR: In this article, a study was made of the movement of lactose, lactic acid, calcium and phosphorus between curd and whey, and of the effect of high acidity developed in the curd before whey separation, on the pH and physical properties of the cheese.
Journal ArticleDOI
Criteria for Judging a True Rumen Organism and a Description of Five Rumen Bacteria
L.S. Gall,C.N. Huhtanen +1 more
TL;DR: Five criteria from judging true rumen bacteria are set up: presence in numbers of 1 million or more per gram of fresh rumen contents, isolation of a similar type bacterium at least ten times from at least two animals, and production by the organism of end-products found in the rumen from substrates found inThe rumen.
References
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Journal ArticleDOI
The colorimetric determination of lactic acid in biological material.
S.B. Barker,William H. Summerson +1 more
Journal ArticleDOI
STUDIES OF ACIDOSIS: VIII. THE DETERMINATION OF β-HYDROXYBUTYRIC ACID, ACETOACETIC ACID, AND ACETONE IN BLOOD
Journal ArticleDOI
Reaktionen und Reagenzien zum Nachweis organischer Verbindungen IV)
TL;DR: In this paper, a verwendete Apparat zeigt ihr gegeniiber gewisse Vereinfachungen ; die Fiillung mit Natronasbest and Phosphorpentoxyd ermSgliehte eine bedeutende Verkleinerung des Absorptionsrohres, wodureh eine besonders groge W~gegenauigkeit erzielt werden konnte; diese Verbesserungen, die fiber den Rahmen
Journal ArticleDOI
THE DETERMINATION OF β-HYDROXYBUTYRIC ACID, ACETOACETIC ACID, AND ACETONE IN BLOOD
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The colorimetric determination of lactic acid in biological material.
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