Anthocyanins
Anthocyanins are water-soluble pigments belonging to the flavonoid group of phenolic compounds. They are primarily responsible for the red, purple, and blue hues of many plants, including grape varieties used in winemaking. In wine, anthocyanins are central to colour expression, stability, and the perception of maturity.[1]
Background
The term derives from the Greek words anthos (flower) and kyanos (dark blue). Anthocyanins occur mainly in the skins of red grapes, though certain teinturier varieties such as Alicante Bouschet contain pigments in both skin and pulp.[2] Their presence has historically distinguished red wine grapes from white, which generally lack significant anthocyanin content.
Characteristics
Anthocyanins are glycosylated forms of anthocyanidins, with malvidin-3-glucoside being the most abundant in grapes.[3] Their colour expression is strongly pH-dependent: appearing red in acidic conditions, purple at intermediate levels, and blue in more alkaline environments.
During ageing, anthocyanins interact with tannins and other phenolic compounds through polymerisation and co-pigmentation, leading to more stable pigments and a gradual shift in colour from youthful purple tones towards brick-red and tawny hues.[4]
Role in Winemaking
Anthocyanins are extracted during maceration and fermentation, with factors such as grape variety, ripeness, temperature, and cap management techniques influencing concentration and stability.[5]
Winemaking choices affect anthocyanin preservation. For example, higher fermentation temperatures can increase extraction, while prolonged oxidation may degrade pigments. Oak ageing, sulphur dioxide levels, and micro-oxygenation also shape pigment stability.
In sensory terms, anthocyanin levels contribute to perceived colour intensity, which is often used as a visual cue for varietal identity, ripeness, and ageing potential.
See also
References
- ↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015.
- ↑ Ribéreau-Gayon, Dubourdieu, Donèche & Lonvaud, Handbook of Enology, Wiley, 2006.
- ↑ Jackson, Wine Science: Principles and Applications, 5th ed., Academic Press, 2020.
- ↑ Cheynier, Phenolic Compounds in Foods and Natural Health Products, American Chemical Society, 2005.
- ↑ Ribéreau-Gayon, Dubourdieu, Donèche & Lonvaud, Handbook of Enology, Wiley, 2006.