Beer phenolic composition of simple phenols, prenylated flavonoids and alkylresorcinols

Beer is a fermented beverage with beneficial phenolic compounds and is widely consumed worldwide. The current study aimed to describe the content of three families of phenolic compounds with relevant biological activities: prenylated flavonoids (from hops), simple phenolic alcohols (from fermentation) and alkylresorcinols (from cereals) in a large sample of beers (n = 45). The prenylated flavonoids analyzed were xanthohumol, isoxanthohumol, 6- and 8-prenylnaringenin. The total prenylated flavonoids present in beer ranged from 0.0 to 9.5 mg/L. The simple phenolic alcohols analyzed were tyrosol and hydroxytyrosol, ranging from 0.2 to 44.4 and 0.0 to 0.1 mg/L, respectively. Our study describes, for the first time, the presence of low amounts of alkylresorcinols in beer, in concentrations ranging from 0.02 to 11.0 µg/L. The results in non-alcoholic beer and the differences observed in the phenolic composition among different beer types and styles highlight the importance of the starting materials and the brewing process (especially fermentation) on the final phenolic composition of beer. In conclusion, beer represents a source of phenolic compounds in the diet that could act synergistically, triggering beneficial health effects in the context of its moderate consumption.This research was funded by the Instituto de Salud Carlos III FEDER (PI14/00072) and by grants from DIUE of Generalitat de Catalunya (2017 SGR138). AB is recipient of a PFIS predoctoral fellowship from the Instituto Carlos III FEDER (PFIS-FI16/00106), NSD is recipient of predoctoral fellowship (2019-DI-47) from Agència de Gestió d’Ajuts Universitaris i de Recerca (AGAUR) Generalitat de Catalunya. JMR is recipient of Marie Skłodowska-Curie grant agreement (No 712949) and from ACCIO. CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN) is an initiative of the ISCIII, Madrid, Spain