Uticaj sorte šljive na prinos rakije šljivovice

Abstract

U radu su prikazani rezultati trogodišnjih ispitivanja uticaja tri sorte šljive sa istog lokaliteta, i jednogodišnjih ispitivanja uticaja pet sorata šljive sa više lokaliteta na potencijalne prinose rakije, stvarne koeficijente iskorišćenja šećera u toku alkoholnog vrenja kljuka od šljive i stvarne prinose rakije.

The paper presents the study of the yield of plum brandy as influenced by different plum cultivars. Fruit quality parameters affecting the yield of plum brandy, i.e. stone ratio, total sugars content, and sucrose ratio in total sugars were investigated. The investigation included the study of plum cvs Čačanska Rodna, Stanley and Požegača grown in the orchards at the Preljina locality. Similarly, the stated parameters of fruits of cvs Čačanska Rodna, Stanley, Čačanska Lepotica, Čačanska Najbolja and Valjevka, grown on different localities over the same period, were also studied over a one-year period. Plum fruits of all cultivars were processed into plum brandy by identical method. Mashed plum fruits, with and without stones, were subjected to spontaneous alcoholic fermentation, epiphytic fruit microflora being the agent. The fermented mash was distilled immediately upon alcoholic fermentation performed using the batch distillation device. The ethanol content in the obtained distillate was 28 vol%. Three-year results of the study of fruits grown at the Preljina locality suggest that the highest plum brandy yield can be expected from the processing of cv Čačanska Rodna whereas cvs Stanley and Požegača followed. In 2004, it was cv Čačanska Rodna that was the cultivar with the highest brandy production potential, regardless of locality, whereas cvs Stanley, Čačanska Lepotica, Čačanska Najbolja and Valjevka followed. Actual yields of plum brandy were generally lower than the potential ones as expected by calculations of stone ratio and fruit sugar content. Values of actual sugar conversion coefficients during the alcoholic fermentation differed from the theoretical ones (0.59), ranging from 0.30 to 0.61 among different cultivars, years and localities. Over a three-year study period of cvs grown at the Preljina locality, the highest coefficient of sugar conversion during alcoholic fermentation was found in cvs Požagača (0.52 and 0.51), Čačanska Rodna (0.48 and 0.49) and Stanley (0.39 and 0.40). Consequently, the actual brandy yields accounted for 87.74% and 85.78% (cv Požegača, with and without stones, respectively) and 66.55% and 67.33% (cv Stanley, with and without stones, respectively) of the theoretical calculation. Over a one-year study period, the highest coefficient of sugar conversion during alcoholic fermentation was found in cv Valjevka (0.53). It was somewhat lower in cvs Čačanska Rodna (0.49), Čačanska Najbolja (0.46), Čačanska Lepotica (0.44) and Stanley (0.38). Hence, the induced correlation between actual and potential brandy yields ranged from 91.49% (cv Valjevka) to 65.97% (cv Stanley). In conclusion, highest potential and actual yields of brandy are obtained by processing of cv Čačanska Rodna, regardless of a year or a locality.