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FORMATION OF ETHYL ACETATE IN FERMENTATION WITH BREWER'S YEAST: V. EFFECT OF SOME VITAMINS AND MINERAL NUTRIENTS
Author(s) -
Nordström Kurt
Publication year - 1964
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1964.tb01983.x
Subject(s) - yeast , chemistry , fermentation , thiamine , biochemistry , glycerol , pantothenic acid , acetic acid , amino acid , metabolism , vitamin
Esters are formed as by‐products in alcoholic fermentation with Saccharomyces cerevisiae . Ester formation is generally stimulated if growth is stimulated, this correlation being apparently due to some regulatory mechanism acting on the energy and acyl‐coenzyme A metabolism rather than to a changed enzymatic pattern of the cell. Addition of lower fatty acids to the medium leads to a decrease in ester formation; in this case yeast growth and formation of esters are inhibited by the same factor acting on the metabolism of acyl‐CoA. If yeast growth is limited by other means, other effects also affect the correlation between ester formation and yeast growth; biotin and thiamine are inhibitory to the formation of ethyl acetate, while iodoacetic acid, 2,4‐dinitrophenol and pantothenic acid are stimulatory. These effects are explained by interactions of these substances on the formation or consumption of acetyl‐CoA. Yeast growth is stimulated by addition of amino acids to wort, and the formation of volatile esters is correspondingly stimulated, but stimulation of ester formation is lower than that required by the increased growth, owing to the inhibition of ester formation by acids; the net result of addition of amino acids to wort depends on the composition of the wort and the pH. Niacin, thiamine and inositol have a considerable effect on the formation of glycerol and acetic acid.