Dinamica acumularii acizilor alfa si a uleiului volatil in conurile de hamei (Humulus lupulus). (Nota 1).
1988
Salontai A. | Tofana M. | Stanescu U. | Moldovan Z.
The environmental conditions of Cluj-Napoca allow for successful cultivation of hop. The dynamics of alpha-acids and the essential-oil accumulation, as well as their fractions were measured in nine hop cultivars produced in Romania - among which: Aroma, Napoca 1 and Transylvania (indigenous), and Huller Bitterer and Brewers Gold (foreign) should be mentioned. Measurements of alpha-acids and of total essential oil were performed every five days between August 10-31, 1987; measurement of the essential-oil fractions was done after 6 months of storage in refrigerator. Alpha-acids were determined by conductometry, essential oil by steam distillation and the fractions through gas-chromatography combined with mass spectrometry. There was found that alpha acids accumulated right in the stages of ones formation when their length was 3-10 mm and ended within approximately three weeks. Essential oil accumulated a bit later and was recorded only during the second measurement (August 15). Of the 24 components of essential oil identified over 70 % were sesquiterpenes (humuled and beta-caryophyllen) and, monoterpenes, mostly myrcene (Table 2). Aroma and Huller Bitterer are remarkable for the essential-oil content and fine fragrance.
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