Study of the Fermentation Kinetics and Secondary Metabolites of Torulaspora delbrueckii Yeasts from Different Substrates

Abstract

Due to global competition and consumer demand for innovative products, the brewing industry is exploiting research to create new beer products with complex aromatic profiles. Recently, interest has been focused on non-Saccharomyces yeast strains, employed in the wine sector. In this study, the capability of two Torulaspora delbrueckii strains (T.d. 291 and T.d. Prelude) on metabolizing the basic sugars of wort was investigated and compared with a S. cerevisiae strain (S.c. US-05). More specifically, the consumption of wort sugars (glucose, fructose, maltose, and their mixtures) and the production of ethanol and secondary metabolites were studied, at two fermentation temperatures (20 °C and 13 °C). From the results of the fermentation kinetics, it was concluded that both T. delbrueckii yeasts are able to metabolize all sugars, produce a satisfactory amount of ethanol and grow at either temperature, although with a faster rate at 20 °C. The volatile compounds were significantly affected by the fermentation temperature and the sugar used. Both T. delbrueckii strains demonstrated potential for use in brewing.

Keywords:

• Maltose
• non-Saccharomyces
• sugar fermentation
• volatile compounds

Declaration of interest statement

The authors declare there are no conflicts of interest.