The Impact of Oxygen at Various Stages of Vinification on the Chemical Composition and the Antioxidant and Sensory Properties of White and Red Wines

Table 1

The influence of oxygen on the initial stages of vinification [1, 4–7].

Adverse effects	Beneficial effects
Changes in taste, colour, and aroma of white wine due to degradation of phenolic compounds	Increased extraction of phenolic compounds from fruit tissues
Formation of deposit in red wine due to phenolic compound precipitation—reduction in the amount of phenolic compounds in the wine	Obtaining more balanced sensory characteristics of wine (such as lower acidity and astringency and increased colour intensity)
	Reduction of the amount of reducing aromas in wine (smell of mould, fungi, dirty cloth, rotten eggs, garlic, or cauliflower)
Hyperoxidation (9 mg O2/L)
Lower intensity of aroma due to the formation of acetates and higher aldehydes (containing from five to ten carbons)	Better resistance of white wine to browning because of removal of proanthocyanidins
	Formation of higher concentrations of compounds favourably affecting the aroma of wine such as; (i) six-carbon compounds (hexane-1-ol, 2-hexenal); (ii) higher alcohols (2-phenylethanol); (iii) fatty acids and their acetate and ethyl esters (hexyl, isoamyl, and 2-phenylethyl acetate and butyrate, decanoate, and ethyl hexanoate); (iv) volatile terpenes