The large varieties of hops and hop products used in the brewing industry. Various in the biochemical composition, individual approaches to the brewing technology of each hop product are required in order to obtain a high-quality beer with a characteristic bitter taste and aroma. The purpose of this work was to study the biochemical composition of pressed conical hops, pellets of hop type 90, type 45, ethanolic and CO2 extracts of hop of various varieties, and their influence on the quality of the finished beer. As a result of comprehensive research on hops and hop products of various varieties, using the modern biochemical methods were determined differences in their biochemical composition depend on the absolute values such parameters as the mass fraction of α-acids, b-acids and their composition, xanthohumol, general polyphenols, essential oils, the ratio of their valuable components of hops: b-acids to a-acids and also for quantity of general polyphenols, essential oils per unit of α-acids. Based on the results of the biochemical composition of hops and hop products were investigated their influence on the quality of beer and were determined their using in brewing.
Introduction. According to the data of foreign studies, prenyl fl avonoids and bitter substances of hop have signifi cant antioxidant, antiviral, antimicrobial, anti-infl ammatory and anti-carcinogenic properties. Methods. A complex of the following methods was used: a monographic method, analysis, synthesis and comparison, mathematical-statistical and modern physical-chemical methods of determining qualitative indices of hop, special and common in hop-growing industry, which allowed obtaining scientifi cally valid results. Results. The modern level of knowledge about biologically active compounds of hop and their properties was analyzed, in particular, bitter substances and xanthohumol. The quantitative and qualitative content of bitter substances, essential oil and xanthohumol in hop varieties of Ukrainian, European and American breeding was studied. Among the Ukrainian varieties, the highest amount of xanthohumol was found in Ruslan and Xanthus varie- ties – 1.16 % and 1.06 % against dry substances respectively, and its minimal amount was detected in the cones of the bitter Alta variety. Among the European varieties, the highest amount of this substance is contained in the German variety HallertauerTaurus – 0.9–1.0 %, up to 1 % in the Czech variety Agnus and the English va- riety Admiral, with the content of 0.95 %–1.09 %. There is a strong correlation between the accumulation of xanthohumol and alpha acids in the formation and ripening of the cones. The maximal amount of xanthohumol is formed in the hop cones in the phase of complete technical ripeness. The content of this substance in hop cones depends on the breeding variety and is a varietal trait, genetically fi xed for each variety. The quantitative amount of xanthohumol may be one of biochemical criteria of identifying the variety. Conclusions. By their characteristics, the Ukrainian hop varieties correspond to the world’s analogues, namely, according to their bio- chemical and technological indices, hop varieties Klon-18 and Zlato Polissia correspond to the characteristics of the hop of the Czech Saaz variety, the biochemical indices of the bitter Alta variety correspond to the Ger- man variety Magnum, and such varieties as Slovianka and Zahrava exceed the world’s analogues considerably in the composition and quality of bitter substances and essential oils and are unique.
Aim. To investigate the quantity and structure of α-, β-acids and xanthohumol in lupulin grains of different hop varieties that essentially differ in these biochemical indexes, and also the presence of the substances both in staminate racemes and in the leaves. Methods. High performance liquid chromatography (HPLC), up-to- date physical-chemical methods of hop quality indicators’ defi nition, special and standard in the hop-growing branch, were applied. Results. It was stated that lupulin of aroma and bitter varieties contains various quantity of α- and β-acids. Therefore, the ratio of α- to β-acids in aroma hop varieties is above one (1), whereas in varieties of bitter type this ratio is much lower than one (1). No correlation between the quantity of lupulin and the contents of α- and β-acids was found. It was noted that the color of lupulin depends upon the quantity of xanthohumol. Conclusions. The performed tests give evidences on lupulin glands are located on anthers of staminate racemes and on the leaves as well, though in much less quantity and less educed. It was found that the quantity and structure of bitter substances in lupulin grains from selection varieties does not depend upon lupulin content in hop cones, but it is a grading factor. Lupulin from the staminate racemes received from various plants essentially differs in quantity of α- and β-acids. This fact is of key importance for pair selection. In petal glands on the leaves of a hop plant bitter substances are represented only by β-acids, mainly lupulone and adlupulone.
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