Alcohol-Free Beer Produced Using Maltose-Negative Wine Yeast <i>Saccharomyces cerevisiae</i> with Probiotic Potential

Abstract

The ideal yeast for the production of alcohol-free beer does not form ethanol, produces a distinct and pleasant taste and has probiotic properties. This study characterized the potential of a wine yeast, Saccharomyces cerevisiae CCM 9181, to be an ideal alcohol free beer strain. It was found to be maltose-negative, and the ethanol content in fermented all-malt wort has never exceeded the legal limit of 0.5% v/v. Its specific growth rate (µ) was the highest at 25 °C (μ = 0.41 ± 0.01 h−1) and it was not affected by iso-α-bitter acids (15–50 IBU, international bitterness units). A response surface methodology was used to optimize the temperature and pitching rate affecting the formation of total higher alcohols and esters. A statistical analysis of the experimental data revealed that temperature affected esters most significantly, while both temperature and pitching rate had the most significant effects on higher alcohols. The sensory properties of beers were evaluated by trained panelists and they were described as malty, clove-like, having a very mild bitterness and a bouquet of white wine. The survival rate of S. cerevisiae CCM 9181 after simulated passage through the gastrointestinal tract was investigated as a first step to evaluate its probiotic properties. Our analyses show that Saccharomyces cerevisiae CCM9181 is a suitable candidate for the large-scale commercial production of alcohol-free beer and has probiotic potential that needs to be studied further.

Keywords

• alcohol-free beer
• volatile compounds
• response surface methodology
• probiotic properties