The influence of storage methods and conditions on oxidation index of bitter substances in the hop granules of Type 90 | Vliyanie sposobov i rezhimov khraneniya na indeks okisleniya gor'kikh veshchestv granul khmelya Tip 90

There is a worldwide trend of a rapid increase in the production of granular hops, but there are still unstudied questions about the changes of granular hops bitter substances during the storage. Taking into consideration the significant differences in the biochemical composition of aromatic and bitter hop varieties, as research objects for the experiments, there were taken hop granules of type 90 which are typical representatives of these groups: Clone 18, Slavyanka (aromatic varieties) and Polessky, Prominy (bitter varieties). Given that the most negative effect on the storage of hops’ valuable substances is because of environmental temperature, humidity and gas composition (presence of oxygen), we chose the following options in order to study the changes in the oxidation index of hops’ bitter substances: 1) vacuum packaging, fixed temperature mode (control); 2) vacuum packaging + CO2, fixed temperature mode; 3) vacuum packaging, t 0 ... + 2 deg C; 4) vacuum packaging + CO2 , t 0 ... + 2 deg C. The obtained results showed that the hop granules of type 90 of aromatic and bitter varieties are best kept in vacuum packaging and CO2 environment at the temperature of t 0 ... + 2 deg C, as during all periods of storage (6, 12, 18 and 24 months), the oxidation index value of bitter substances in hops was the lowest, i.e. the granules, in such storage conditions, recorded the best brewing qualities. The granules of type 90 of Slavyanka and Polessky varieties recorded worse brewing quality than the granules of Clone 18 and Prominy varieties. Therefore, first of all, for the production of beer, granular hops of Slavyanka and Polessky varieties should be used. Also, there is no doubt as to the need to ensure better storage conditions for Slavyanka and Polessky hop varieties than for Clone 18 and Prominy hop varieties.