Evaluation of α- and β-bitter Acids Content in Harvest of Czech Hops in 2016

Abstract

The contents of α- and β-bitter acids from hops harvested in the Czech Republic in 2016 have been evaluated. Samples originated from all growing areas – Žatec, Úštěk and Tršice (77.3%, 10.7% and 11.9% of the hop garden areas in the Czech Republic). The tested varieties, Saaz (ŽPČ), Sládek, Premiant, Agnus, Kazbek and Saaz Late were cultivated on 87.8%, 5.6%, 3.7%, 0.8%, 0.4 and 0.9 of the harvest areas respectively. Samples were analyzed in accordance with the Analytica EBC, method 7.7 (HPLC), all results are given in weight % in dry matter. The average value of α-bitter acids in the Saaz hops (3.35%) was 1,20% (55.8% rel.) when compared to the year 2015 and 0.20% (5.6% rel.) lower to the average of the 23 years. The content of β-bitter acids (4.99%) was 1.75 % (54.0% rel.) and 0.33 % (7.0 % rel.) higher when compared to the year 2015 and to the long-term average respectively. The content of α-bitter acids in the Sládek hops (7.29%) was 2.20% (43.2% rel.) and 0.64% (9.6% rel.) higher when compared to the harvest in 2015 and to the average of the 13 years respectively. The content of α-bitter acids in the Premiant hops (9.02) was in 2.43% (36.9% rel.) higher when compared to the harvest in 2015 and comparable to the average of the last 13 years. The content of α-bitter acids in the Agnus hops (9.70) was in 0.80% (7.6% rel.) and 1.40% (12.6% rel.) lower when compared to the harvest in 2015 and to average of last 8 years. The content of
α-bitter acids in the Kazbek (4.96%) and Saaz Late (4.76%) varieties was in comparison with the harvest in 2015 0.37% (8.1%rel.) and 2.6% (119% rel.) higher. The ratio α/β bitter acids, the relative content of cohumulone in the total α-bitter acids and the relative content of colupulone in the total β-bitter acids were also in agreement with the long-term averages found for the tested varieties.