VOLATILE CONSTITUENTS OF VINEGAR. IV. FORMATION OF VOLATILES IN THE FRINGS PROCESS AND A CONTINUOUS PROCESS OF MALT VINEGAR MANUFACTURE

Gas liquid chromatography was used to fractionate and measure volatiles formed during the Frings process and during a continuous process of malt vinegar manufacture. Acetaldehyde, ethyl alcohol, iso-amyl alcohol, acetic acid, n-propyl alcohol, sec-butyl alcohol, isobutyl alcohol, n-amyl alcohol, and also sec-butyl acetate, isobutyl acetate and n-amyl acetate were detected during the alcoholic fermentation but propionic acid, isobutyric acid and acetoin were produced during acetification. The increase in the number and concentration of the volatiles of these processes has been compared with those found for the Quick method.     

VOLATILE CONSTITUENTS OF VINEGAR. I. A SURVEY OF SOME COMMERCIALLY AVAILABLE MALT VINEGARS

Gas liquid chromatography was used to fractionate the alcohols, esters, carbonyls and acids in commercial malt vinegars. A qualitative and quantitative study was made using two different stationary phases; methyl formate, acetaldehyde, ethyl acetate, ethyl alcohol, isobutyl acetate, n-propyl alcohol, n-butyl acetate, isobutyl alcohol, amyl alcohol, acetoin, propionic acid and acetic acid were identified and estimated in eleven different malt vinegars. The results of this survey were compared with the information previously found for malt and other types of vinegars. A preliminary assessment has been made of the origins of these volatiles.     

STUDIES IN TOWER CONTINUOUS FERMENTATION. I. METHODS FOR THE CHARACTERIZATION OF FLOCCULENT YEASTS

Methods have been developed for the characterization of flocculent brewer's yeast based on a modification of the Burns method and on the use of an automatic recording spectrophotometer. Strains of Saccharomyces spp. with known characteristics in tower continuous fermentation were used to examine the methods and to correlate the values obtained with those found using the Burns method.