Non-Saccharomyces yeasts for beer production: Insights into safety aspects and considerations

Abstract

The application of non-Saccharomyces yeasts in beer as a natural tool for innovation, to create different aroma profiles and flavoured non-alcoholic beers, has attracted great interest from both researchers and commercial brewers. As a result, a higher diversity of non-Saccharomyces yeasts for beer production is expected on the market in the coming years. However, the safe use of non-Saccharomyces yeasts has not been broadly investigated and no guidance for the safety assessment of yeasts is published. The fundamentals of a safety assessment include an accurate taxonomic species identification using up-to date methods, along with a literature study regarding the yeast species in question. The strain-specific safety concerns that should be assessed involve pathogenic potential, antifungal resistance, production of biogenic amines and possible allergic reactions. However, yeast safety assessment is in its infancy compared to bacterial safety assessment and research is needed to set cut-off values for antifungal resistance, identify potential virulence genes and validate screening tools to assess yeast strains. Finally, the individual breweries are responsible for the safety related to the process in which yeasts are applied and throughout the shelf life of the beer. The application of non-Saccharomyces yeasts for industrial beer production is promising in terms of defining new prototypes and developing healthier and safer beers, but only if good food safety measures, i.e., both for the strain and the production process, are in place throughout the food value chain. In this way, the ancient role of yeasts in making beverages safer and thereby improving food safety is emphasized.

Keywords: Brewery; Food safety; Non-conventional yeasts; Safety assessment; Starter culture.