Effect of blueberries addition during beer maturation on yeast metabolism

Abstract

In recent years, there has been a significant interest in beverages with increased biological value, such as beer with blueberries. In this study, blueberries were added at the beginning of maturation of lager beer with an initial extract of 12, 14 and 16ºP. The effect of blueberries addition on yeast metabolism was investigated as concentration of ethanol, higher alcohols, esters, aldehydes, and vicinal diketones in the final beer were measured and compared to control samples without blueberries. The results showed that blueberries affected positively ethanol formation only when wort with initial extract of 12°P was used and had no significant effect when wort with higher extract was used. In regard to secondary metabolites, blueberries addition led to a decrease in higher alcohols concentration and an increase in esters amounts. All the carbonyl compounds (aldehydes and vicinal diketones) were higher in beer with blueberries.