Vicinal Diketone Production and Amino Acid Uptake by Two Active Dry Lager Yeasts during Beer Fermentation
- 1 June 2007
- journal article
- research article
- Published by Taylor & Francis Ltd in Journal of the American Society of Brewing Chemists
- Vol. 65 (3), 138-144
- https://doi.org/10.1094/asbcj-2007-0515-01
Abstract
Amino acid consumption and vicinal diketone (VDK) production of two different strains of commercially available active dry lager yeasts (ADLYs) were compared with freshly propagated cultures of the corresponding yeast strains. Rehydrated dry yeasts and freshly propagated yeasts were pitched in all-malt wort and allowed to ferment at 14°C. Dry yeast strains took 15–26 hr longer to attenuate the wort to final gravity and 24–48 hr longer to significantly reduce wort amino acid content. A new indicator was introduced as a means to quantitatively characterize VDK production and reduction profiles. This indicator effectively demonstrated a large discrepancy in the diacetyl profile between the fresh and dry cultures: fermentations made with dried yeasts resulted in 1.5–7 times higher diacetyl indices. With one of the dry strains, diacetyl concentrations remained over the taste threshold value after 7 days of fermentation. These differences could be linked to a reduced ability of the rehydrated mother cells to absorb wort constituents caused by cell membrane damage occurring during the ADLY production process. Overall, dry yeasts resulted in a reduced level of performance compared with freshly propagated cultures, suggesting that the direct utilization of ADLY as an inoculum for beer fermentation at the industrial scale is not recommended.Keywords
This publication has 12 references indexed in Scilit:
- Enzymology of Vicinal Diketone Reduction in Brewer's YeastJournal of the Institute of Brewing, 2004
- Mechanism of viability loss during fluidized bed drying of baker's yeastFood Research International, 1997
- Role of the trehalose carrier in dehydration resistance of Saccharomyces cerevisiaeBiochimica et Biophysica Acta (BBA) - General Subjects, 1993
- The role of trehalose in dehydration resistance ofSaccharomyces cerevisiaeFEMS Microbiology Letters, 1987
- Characteristics of cellular membranes at rehydration of dehydrated yeast Saccharomyces cerevisiaeApplied Microbiology and Biotechnology, 1984
- Reverse-phase liquid chromatographic analysis of amino acids after reaction with o-phthalaldehydeAnalytical Biochemistry, 1980
- THE EBC-NINHYDRIN METHOD FOR DETERMINATION OF FREE ALPHA AMINO NITROGENJournal of the Institute of Brewing, 1973
- Fluorescence reaction for amino acidsAnalytical Chemistry, 1971
- UPTAKE OF AMINO ACIDS IN BOTTOM FERMENTATIONSJournal of the Institute of Brewing, 1969
- ABSORPTION OF AMINO ACIDS FROM WORT BY YEASTSJournal of the Institute of Brewing, 1964