Uticaj izazivača alkoholnog vrenja kljuka šljive bez koštica na kvalitet šljivovice

Abstract

U proizvodnji šljivovice, kao izazivači alkoholnog vrenja kljuka šljive, mogu da se koriste epifitna mikroflora plodova šljiva ili selekcionisani kvasci koji se dodaju u nesterilni kljuk šljive. U radu je ispitivan uticaj spontanog alkoholnog vrenja kljuka šljive bez koštica, čiji je izazivač epifitna mikroflora, na kvalitet šljivovice, pri čemu su, u zavisnosti od načina odvajanja koštica kljukovi imali različite fizičke karakteristike (kljuk od izmuljanih šljiva bez koštica i kljuk od ispasiranih šljiva bez koštica). U ispasirani, nesterilni kljuk šljive dodavana su, kao izazivači vrenja, i dva soja selekcionisanih kvasaca Saccharomyces cerevisiae. Za ispitivanja su korišćene sorte šljive Stenli, Požegača i Čačanska rodna. Kvalitet dobijenih šljivovica (hemijski sastav, zdravstvena vrednost i senzorne karakteristike) zavisio je, kako od načina proizvodnje (primarne prerade i izazivača vrenja) u okviru jedne sorte, tako i od sorte šljive u okviru istog načina prerade šljiva u rakiju.

The paper examines the method of the separation of stones from the fruit and the various microflora (indigenous microflora and selected yeasts) as the agents of alcoholic fermentation, and the impact that these have on the characteristics of the plum brandies produced from cultivars Stanley Požegaca and Čačanska Rodna, in the 2002 vintage. Variant 1 included crushing and mixing stone-free plums and spontaneous fermentation. Variant 2 included spontaneous fermentation of pulped plum fruits, while variants 3 and 4 made use of pure cultures of selected yeasts (Saccharomyces cerevisiae, Premium Blanc 12V strain, and Saccharomyces cerevisiae Montrachet strain) as the agents of alcoholic fermentation, both with pulped plum mash. In all of the variants, the distillation of the fermented mash was done immediately after the alcoholic fermentation, using the copper pot still, and the obtained brandy contained around 28% v/v ethanol. The re-distillation of the soft brandy was done using the same device, with the separation of the fractions: the head (1%), the heart and the tail. The ethanol content in the heart was around 60% v/v. For the purposes of the chemical analysis and sensory assessment, this was scaled down to around 45%v/v, using distilled water. The use of the selected yeasts as the agents of alcoholic fermentation of the pulped stone-free plum mash (variants 3 and 4), had as a result a decrease in the content of the total acids and esters in the plum brandy, when compared to the brandies obtained through spontaneous fermentation of the pulped mashes (variant 2) or crushed (variant 1) stone-free plum mash. The contents of benzaldehydes, HCN methanol, and furfural are more influenced by the cultivar than by the method of processing the plum into the brandy. The content of higher alcohols and total aldehydes in the brandy depended both on the method of separation of the stone from the fruit and from the agent of alcoholic fermentation; at the same time, the same type of the yeast had a different impact on the different plum cultivars. With the Požegača cultivar, the brandies that were made from pulped plums and with added selected yeasts received higher marks for sensory characteristics. With Stanley and Čačanska Rodna cultivars, better marks were given to brandies that were produced using indigenous microflora as alcoholic fermentation agents.