The effect of yeast growth stages on the absorption of polyphenols
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Kuupäev
2020
Kättesaadav alates
Autorid
Harbah, R.A.
Meledina, T.V.
Morozov, A.A.
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Colloidal stability of beer is one of the most critical challenges facing the brewing
industry. In brewing, stabilization agents are widely used to remove colloids such as proteins and
polyphenols. However, the removal efficiency of polyphenols depends on the yeast, which
adsorbs these compounds on its surface. The adsorption of polyphenols on the yeast surface is
associated with the zeta potential of the cell wall, which correlates with the mannan content in
them. The purpose of the study was to investigate the role of yeast strains in adsorption of
polyphenols (increasing colloidal stability of beer) and the correlation of this property with the
mannan content in the cell wall during the fermentation. Two S. cerevisiae strains were used in
this study, and the specific growth rate of yeast, the specific rate of change in the polyphenol
content and the mannan content were determined. The results of this study showed that the highest
mannan content in yeast was after 9 hours (the end of exponential growth phase). Its content was
10.97% by weight of dry matter in the yeast S. cerevisiae Californian Lager (M54), and 13.69%
in the yeast S. cerevisiae Belgian Wit (M21). The desorption of polyphenols was observed during
the period from 9 to 24 hours of fermentation, where an increase in the content of polyphenols in
the medium was observed. Based on these results, it is necessary to remove the yeast at the end
of the exponential growth phase to increase the colloidal stability of the beer.
Kirjeldus
Märksõnad
colloidal stability, mannan, polyphenols, S. cerevisiae yeast, articles