The influence of Whole-cluster pressing and cold maceration on the content of selected polyphenolic components during wine production

In this experiment changes in the contents of the selected phenolic compounds during the vinification process of white wines have been investigated. Two different methods (0-hour maceration variant and 24-hour maceration variant) of grape processing were applied.The 14 specific phenolic compounds from hydroxybenzoic acid (gallic acid, protocatechuic acid, 4-hydroxybenzoic acid, vanillic acid, syringic acid), hydroxycinnamic acid (caffeic acid, caftaric acid, grape reaction product (GRP), p-coumaric acid, coutaric acid, ferulic acid, fertaric acid) and flavan-3-ol (catechin, epicatechin) groups were identified by high-performance liquid chromatography. The lower levels of all individual hydroxybenzoic acids were noted, mostly with statistical differences, for wine treated with cold maceration. Also, the levels of individual hydroxycinnamic acids, with the exception of p-coumaric acid, were lower in the wines treated with cold maceration than in those of the whole-cluster pressing variant.The concentration of catechin from the flavan-3-ol group was lower in the cold maceration variant, while the concentration of epicatechin was lower in the whole-cluster pressing variant without statistical significance. Data comparison of the time horizon showed a similar trend in the behaviour of phenolic substances during the vinification process between variants.