Metabolomical study of hop varietals and evaluation of their metabolites contributing for the final composition of Ale and Lager beers

Abstract

Hops contribute several attributes to the beer, among them bitterness, flavor and aroma. Different varietals of this species produce different profiles of secondary metabolites, giving diverse aromas, flavors and bitterness in beer. Different strains of yeast also contribute to different metabolites for beer, complementing the aromas and flavors introduced by hopping. In addition, brewer's yeast biotransforms substances from hops' essential oils. Brazil currently ranks third in the world ranking of beer production, with the craft beers sector growing at around 20% per year. However, practically all hops used in beer production are still imported, with only a few experimental farms growing hops in the country. Thus, the present proposal aims to evaluate and compare different varietals of hops from different origins to provide methods of recognition of origin and varietal using metabolic fingerprints and to investigate the fate of the hops' secondary metabolites, as well as those produced by different yeasts, in the final beer. The differences obtained due to the use of different methods of hopping and different strains of ale and lager yeasts will be evaluated as well, aiming at a better understanding of the dynamics of hopping and biotransformations by yeast in beer production. In addition to state-of-the-art and innovative scientific production in the areas of brewing and metabolomics, it is expected that this study will generate knowledge that can be used, among others, by hop producers and breweries, both in Brazil and abroad. Such knowledge will contribute to elucidate the best approaches to be used by breweries to obtain specific desired beer profiles. (AU)