Iso-α-acids is a group of compounds which have an important participation in beer flavor. They are responsible for the bitterness which is provided by the hops used during brewing. This study was conducted in order to characterize some Brazilian and North American beers according to bitter characteristics, as Bitterness Units (BU), through the use of a spectrophotometric method or as total iso-α-acids and their isohumulone, isocohumulone, and isoadhumulone fractions by HPLC. Most of the beers evaluated were lager pilsener coming from market leader industries, ale and others produced in microbrewing plants. The Indian Pale Ale beer type, produced by late hopped process, showed the highest BU although the iso-α-acids content in this brand were not as higher as the BU compared to the other samples. North American lager beers presented lower intensities of bitter taste followed by the Brazilian brands (11-15 BU). With regards to the fractions of iso-α-acids, it is distinguished that isoadhumulona was the fraction of lower concentration in all the samples, and the majority of the samples showed higher concentration of isohumulona. The range of isohumulona was between 3,0 and 17,0 mg.L-1.
beer; bitterness; hop; iso-α-acids; Bitterness Units
