Anotace:
Rhamnus prinoides (gesho) which is belongs to the family Rhamnaceae and order Rhamnales is a dicotyledonous angiosperm plant. In Ethiopia, the plant is utilized as a bittering agent in local alcoholic beverages. Due to its bittering substance compositions it could have the potential to be used as a raw material for alcoholic beverages. However, knowledge of its potential as a hop substitute during alcoholic beverage production is limited. The major goal of this research was to investigate the potential of R. prinoides as a raw material substitute for hops in the production of alcoholic beverages. Bittering substance of R. prinoides and physic-chemical of finished beer were done. Four beer types were identified and designated as A, B, C and D (control). The analysis of key brewing variables of the R. prinoides was as follows: total resin (15.96-16.02%), ISO-alpha acid (1.17-1.45 mg/l), alpha acid (1.44-1.92 mg/l), essential oil (3-.0-3.07 %), were obtained. Beer type C (7.4+0.01%w/w and 9.5+0.01%v/v) has been shown significantly (p<0.05) greater concentration of alcohol in comparison with other beer types. Real degree of fermentation value of beer type D (66.29+0.03%) was significantly (p<0.05) different compared with other beer types. Bitterness value (2.2 to 2.8) of the beer produced by R. prinoides was in the range of the values (0-100) of common hopped beer. The bitter substance compositions and key brewing variables of beer produced by R. prinoides are comparable with hop. This indicates that R. prinoides can serve as a substitute for hops in the breweries.