INFLUENCE OF OENOCOCCUS OENI AND OAK CHIPS ON THE CHEMICAL COMPOSITION AND SENSORY PROPERTIES OF CIDER

Cider quality is influenced by several factors, namely, apple variety, yeast strains, fermentation and maturation conditions. The aim of current research was to evaluate influence of lactic acid bacteria Oenococcus oeni and oak chips on the quality of apple cider. After main fermentation lactic acid bacteria Oenococcus oeni (LAB) and two types of oak chips: unroasted oak chips (U_OC) and medium roasted oak chips (MR_OC) were added to cider and samples were matured for four weeks. For matured ciders total phenolic compounds (TPC) were determined spectrophotometrically, individual phenolic compounds by HPLC, volatile compounds by SPME followed by GC/MS and sensory properties using line scale and ranking test. The TPCin ciders ranged from 1028 mg L-1 in cider LA to 1526 mg L-1 in cider MR_OC. Among analysed phenolic compounds chlorogenic acid dominated in all samples. In cider MR_OC comparing with control sample higher content of caffeic acid, epicatechin, ferulic acid and vanillin was determined. The highest total peak area was determined in cider U_OC. Principial component analysis showed that profile of volatile compounds can be explained by three factors; the first two represent 81% of the total variances. The characteristic volatiles of cider LAB were acetic acid, ethyl-9-decanoate, etildecanoate, octanoic acid, and etylhexanote, in cider MR_OC 3-methyl-l-butanol acetate, butyl acetate and ethyl acetate, whereas in cider U_OC 3-methyl-1-butanol and phenylalcohol. Preference ranking test results showed that the assessors preferred cider LAB. Addition of Oenococcus oeni, unroasted and roasted chips during maturation significantly influence chemical composition and sensory properties intensity of cider.