The Production of Aroma Compounds by Yeast

Abstract

The yeast plasma membrane regulates the movement of compounds into the yeast celj and of yeast metabolites from the cell into the medium. The rate of penetration of organic acids into the yeast cell depends on their lipophilic nature, and on their molecular size and degree of branching. During fermentation yeast synthesizes a vast number of aroma compounds. The numerically and quantitatively largest groups of aroma compounds include fusel alcohols, fatty acids and fatty acid esters. The yeast used and the fermentation conditions can influence the formation of aroma com pounds. The yeast also has a profound effect on the formation of other aroma compounds, such as sulphur compounds and phenols. In addition to fermentation, the maturing of a beverage can also influence the aroma. During the maturing lactones, phenols and other compounds are extracted from the oak casks in which the beverage is aged. The presence of the so-called "whisky lactone", p-methyl-Y-octalactone, is characteristic of a beverage that has been matured in oak.

Analysis of the secondary compounds produced by Saccharomyces cerevisiae and wild yeast strains during the production of "cachaça"

“…According to Soumalainen and Lehtonen (25), the type of inoculum and the fermentation conditions may interfere with the formation of aromatic substances, and may have influence on the production of other substances such as sulphur and phenolic compounds.…”

“…According to Soumalainen and Lehtonen (25), the levels of propanol, isobutanol and isoamylic alcohol produced during the fermentation of grape must varied considerably depending on the yeast strain that was used. These results are similar to the obtained in this study, since yeast strains produced different quantities of secondary compounds.…”

“…A good balance among volatile compounds is essential to produce a high quality sugar cane spirit or "cachaça" (1). Thus, many studies evaluated the influence of yeast strains in the formation of flavour compounds in different alcoholic beverages such as wine, beer, whisky, cognac and rum (6,12,13,15,16,25). These studies suggest that the differences in the flavour components are attributed mainly to the yeast strains.…”

The Role and Use of Non-Saccharomyces Yeasts in Wine Production

“…The range of flavour compounds produced by different yeasts is well documented (Castor, 1954;Suomalainen & Lehtonen, 1979;Soles et al, 1982;Nykänen, 1986;Rauhut, 1993;Romano & Suzzi, 1993a;Lambrechts & Pretorius, 2000;Rojas et al, 2003;Romano et al, 2003;Moreira et al, 2005;. The metabolic products resulting from non-Saccharomyces growth include glycerol, acetaldehyde, acetic acid, succinic acid, higher alcohols and fatty acid esters (Fleet et al, 1984;Bisson & Kunkee, 1991;Jackson, 1994;Boulton et al, 1996;Lonvaud-Funel, 1996;Heard, 1999;Zohre & Erten, 2002;Clemente-Jimenez et al, 2004).…”

A fração volátil das aguardentes de cana produzidas no Brasil

“…As notas odoríferas de fruta percebidas no aroma das bebidas alcoólicas são, geralmente, associadas à presença de ésteres de ácidos graxos de MM baixa. 38,39 De fato, uma nota odorífera semelhante à de "maçã", identificada no aroma de tequila, foi associada à presença de hexanoato de etila. 30 Também foi estudado o efeito do tipo de alambique na composição de ésteres em amostras de aguardente.…”