Chemical characteristics of wine distillates from grapevine varieties ‘Kraljevina’ and ‘Ranfol’

Sorte korištene u proizvodnji vinjaka vrhunske kvalitete, određene su specifičnim karakteristikama poput visoke ukupne kiselosti, niske koncentracije šećera i niske pH vrijednosti. U navedenu kategoriju sorata može se svrstati nekoliko hrvatskih autohtonih sorata, među kojima su \u27Kraljevina\u27 i \u27Ranfol\u27. Posjedovanjem navedenih karakteristika, može ih se nazvati potencijalno prikladnim sortama za proizvodnju rakija od vina, osobito vinjaka. Cilj ovog rada je evaluacija karakteristika vinskih destilata od sorata vinove loze \u27Kraljevina\u27 i \u27Ranfol\u27 te procjena njihove prikladnosti za proizvodnju rakija od vina i vinjaka u Republici Hrvatskoj. Berba i alkoholna fermentacija provedeni su na vinogradarsko-vinarskom pokušalištu „Jazbina“, a destilacija u laboratoriju Zavoda za vinogradarstvo i vinarstvo Agronomskog fakulteta u 2017. godini. Provedena je analiza kemijskog sastava vina i srednjeg toka destilata metodama propisanim od O.I.V.-a. Određivanje hlapivih spojeva poput viših alkohola, estera, metanola i acetaldehida provedeno je metodom plinske kromatografije s plameno-ionizacijskim detektorom. Prema osnovnim kemijskim parametrima određenim u srednjem toku destilata proizlazi kako sorte vinove loze \u27Kraljevina\u27 i \u27Ranfol\u27 imaju svojstva koje ih čine prikladnim za proizvodnju vinjaka. Cilj istraživanja i dobiveni rezultati vrlo su značajni za poticanje šire i češće upotrebe navedenih sorata za ovu namjenu.The grapevine varieties used in the production of high quality brandy, are determined by specific characteristics such as high total acidity, low sugar content and low pH. Several Croatian autochthonous varieties, like \u27Kraljevina\u27 and \u27Ranfol\u27, can be classified in the mentioned category. These varieties can be called potentially suitable for the production of wine brandies. The main aim of this research is to evaluate the characteristics of wine distillates obtained by ‘Kraljevina’ and ‘Ranfol’ varieties and to estimate their suitability for the production of wine brandies in Republic of Croatia. Grape harvest and alcoholic fermentation were carried out on the experimental vineyard "Jazbina", and distillation in the laboratory at Faculty of Agriculture, Department for Viticulture and Enology in 2017. The chemical analysis of the wine, and analysis of the chemical composition of ‘the heart’ of distillates were performed according to O.I.V. methods. Determination of the volatile compounds of distillates like higher alcohols, esters, methanol and acetaldehyde were performed by gas chromatographic method with flame ionization detector. Conclusion is that the grapevine varieties \u27Kraljevina\u27 and \u27Ranfol\u27 contain the necessary characteristics that make them suitable for the production of wine brandies, according to the chemical parameters determined in ‘the heart’ of the distillates. The given goal and obtained results have great importance to encourage the widespread use of these varieties for this purpose