Dioxide In Wine Research Articles

Formation of α‐ketoglutaric acid by wine yeasts and its oenological significance

Abstractα‐Ketoglutaric acid was measured enzymically in wines made in the laboratory from three grape varieties by pure cultures of 12 wine yeasts of the genus Saccharomyces. The results were confirmed with the same juices and 4 yeasts on pilot‐plant scale in replicated 30 gallon lots.Mean values for the 12 yeasts ranged from 9 to 117 ppm (overall mean 53). In any one juice the yeasts differed by at least 10‐fold in the amounts produced, and certain yeasts produced consistently high or low yields in all juices. The amounts of α‐ketoglutaric acid produced depended somewhat on the grape juices used, even though these had comparable pH values, and a significant yeast‐juice interaction occurred. The amount of α‐ketoglutaric acid formed during fermentation at 15° was 60 per cent of that formed at 25°, and over twice as much was formed at pH 4.2 as at pH 3.0, using four yeast strains. Formation of α‐ketoglutaric and pyruvic acids were not significantly correlated.The α‐ketoglutaric acid content of 18 white table wines made under comparable conditions on pilot‐plant scale from different grape varieties using the same yeast strain ranged from 38 to 152 ppm (mean 90).The significance of the results is discussed, particularly in relation to the binding of sulphur dioxide in wine, and recommendations are given on how to make wines which are low in α‐ketoglutaric acid.Formation of α‐ketoglutaric acid by three yeasts in a chemically defined medium was lower with increased amounts of nitrogen as ammonium sulphate and higher in the presence of L‐glutamic acid, both being used separately as sole nitrogen sources. These findings are discussed in relation to the rǒle of α‐ketoglutaric acid in nitrogen metabolism of yeasts.

Enzymatic Determination of Carbon Dioxide in Lightly Carbonated Wine—1963 Collaborative Study

Abstract The titrimetric method for determining carbon dioxide in wine, using carbonic anhydrase, was studied collaboratively for the second year. Sample preparation was improved, and two modifications were made in the apparatus: a 5 ml instead of a 10 ml buret and a 25—30 ml automatic pipet instead of a 50 ml buret. Results were good, and it is recommended that the method be adopted as official, first action.

Enzymatic Determination of Carbon Dioxide in Lightly Carbonated Wines—1962 Collaborative Study

Abstract The titrimetric method for determining carbon dioxide in wine using carbonic anhydrase (presented at the 1961 AOAC Meeting) was studied collaboratively. Six laboratories analyzed 20 samples by the enzymatic method. Results varied considerably, and it is recommended that the method be studied collaboratively for another year.

Determination of Carbon Dioxide in Wine

Journal Article Determination of Carbon Dioxide in Wine Get access John E Beck John E Beck Alcohol and Tobacco Tax Division Laboratory, Internal Revenue Service, Washington 25, D.C Search for other works by this author on: Oxford Academic Google Scholar Journal of Association of Official Agricultural Chemists, Volume 43, Issue 3, 1 August 1960, Pages 652–654, https://doi.org/10.1093/jaoac/43.3.652 Published: 04 February 2020

Determination of Carbon Dioxide in Wines by Using a Vacuum System*

Journal Article Determination of Carbon Dioxide in Wines by Using a Vacuum System* Get access Maynard J Pro, Maynard J Pro Alcohol and Tobacco Tax Division Laboratory, Internal Revenue Service, Washington 25, D.C. Search for other works by this author on: Oxford Academic Google Scholar Arthur Etienne, Arthur Etienne Alcohol and Tobacco Tax Division Laboratory, Internal Revenue Service, Washington 25, D.C. Search for other works by this author on: Oxford Academic Google Scholar Frank Feeny Frank Feeny Alcohol and Tobacco Tax Division Laboratory, Internal Revenue Service, Washington 25, D.C. Search for other works by this author on: Oxford Academic Google Scholar Journal of Association of Official Agricultural Chemists, Volume 42, Issue 4, 1 November 1959, Pages 679–683, https://doi.org/10.1093/jaoac/42.4.679 Published: 03 February 2020

Rapid Determination of Sulfur Dioxide in Wine

Journal Article Rapid Determination of Sulfur Dioxide in Wine Get access Alex P Mathers Alex P Mathers Alcohol Tax Unit Laboratory, Bureau of Internal Revenue, Washington 25, D.C Search for other works by this author on: Oxford Academic Google Scholar Journal of Association of Official Agricultural Chemists, Volume 32, Issue 4, 1 November 1949, Pages 745–750, https://doi.org/10.1093/jaoac/32.4.745 Published: 11 February 2020

Report on Sulfur Dioxide in Wine

Report on Sulfur Dioxide in Wine