Physicochemical properties and antioxidant activity of craft and commercial beers marketed in Romania

Abstract

Beer quality is determined by a multitude of physicochemical characteristics and bioactive properties, which influence not only the taste and appearance of the product, but also its functional potential on the consumer’s health. The present study aimed to determine the physicochemical properties and in vitro antioxidant activity of a total of 21 samples of different beer types, such as Lager, Australian Pale Ale, Indian Pale Ale, Amber, Double Amber Dark Lager, Black, Stout, and Porter. The physicochemical characteristics considered in the study were EBC color, pH, total titratable acidity, soluble proteins, and viscosity. The biological activity of the beer was assessed by determining the antioxidant activity as DPPH and ABTS radicals scavenging activity and the total phenolic content. Both DPPH and ABTS-based methods indicated that wheat beers presented the lowest in vitro antioxidant activity among all tested samples, while the highest value was registered for black beer types. Results showed that antioxidant activity parameters were correlated with the original extract declared by the producers, which varied from 10.6 to 16.8 °P. Beer color varied from 8.5 EBC units (blonde Pilsner) to 250 - 253 EBC units (dark beers such as Amber, Black, and Porter), with no correlation between antioxidant activity and color. Other important correlations were found between original extract and energy value, alcohol content, viscosity or total phenolic content.