engleski

Changes of aroma and polyphenolic composition of white wines during alcoholic fermentation.

Aroma and polyphenolic compounds are important constituents of wine as they contribute to the quality of the final product. Most active aroma compounds are produced or modified during alcoholic fermentation. The aim of the present work was to study the changes of aroma and polyphenolic composition of white wines during the alcoholic fermentation and after a short time of storage. The changes of aroma compounds were determined by using headspace solid phase microextraction (HS-SPME) coupled with gas chromatography (GC/FID and GC/MS). (E)-2-hexenal, 2-ethyl-1-hexanol, 1-hexanol, geraniol, nerol and linalool were the most representative compounds determined in grape juice, whereas ethyl esters of hexanoic, octanoic, decanoic and dodecanoic acids, hexyl acetate, isoamyl acetate, as well as isobutanol, isoamyl alcohol and 1-hexanol were identified as the main compounds in wine. The phenolic composition (hydroxybenzoic acids, hydroxycinnamic acids and flavan-3-ols) was determined by the high performance liquid chromatography (HPLC) with photodiode array detection. Gallic, protocatechuic, vanillic and p-coumaric acids were the major phenolic substances in grape juice. whereas caffeic acid was the most abundant phenolic acid in the wine. The most abundant flavan-3-ols identified in all studied samples were (+)-catechin and (-)-epicatechin.

polyphenolics; white wine; fermentation

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