Erythorbic Acid
Erythorbic acid is added to wine to protect from oxidation and also to bind with some of the oxidative products to reduce their organoleptic effect. It is also known to prevent the loss of color, flavor and aromatic compounds, particularly in white wines. Recognised by the OIV, erythorbic acid is permitted for use in grape wine in 30 countries worldwide.
Isoascorbic acid, or D-ascorbic acid or erythorbic acid has the same antioxidant power as ascorbic acid and can be used for the same oenological purpose. This acid exhibits the same appearance and the same solubility properties as ascorbic acid. For further substance information, please see the International Oenological Codex.
Synonym(s): D-Araboascorbic acid, Erythorbate, Isoascorbic acid
CAS Number: 89-65-6
E Number: 315
INS Number: 315
International Organisations
Codex Alimentarius
-Classification, Food Category, Functional Class and Recommended Usage is not available at this time.
International Organisation of Vine and Wine (OIV)
-Classification, Food Category, Functional Class and Recommended Usage is not available at this time.
FIVS
Classification Category 4 – Not naturally occurring in grapes and treatment residual in wine Recommended Usage Good Manufacturing Practice (GMP)
As outlined in the OIV’s International Code of Oenological Practices, Erythorbic Acid: Has the same antioxidant power as ascorbic acid and can be used for the same oenological purpose.
Usage in Winemaking:
Erythorbic acid has been used in the wine industry as an antioxidant due to its ability to rapidly remove molecular oxygen (O2) from juice or wine. This reaction between ascorbic acid and O2 takes place almost 1,700 times more rapidly than that between sulphur dioxide (SO2) and O2. SO2 does not react directly with O2, but instead it reacts mainly with hydrogen peroxide (H2O2), which is formed by the oxidation of a phenolic component. Erythorbic acid can be used to prevent oxidative browning of wine by reversing the first step of phenol oxidation.
Winemakers add erythorbic acid when wines contain disulfide for the following reasons:
Smaller quantities of disulfide give wines a rubber or garlic smell. When very small quantities are present, disulfide can give wine a vague, dirty odour. At even lower levels, disulfide may not produce a specific odour. Minute quantities of disulfide are sometimes not detectable but can kill the normal bouquet of a fine wine.
When erythorbic acid is added to wine, the reaction between erythorbic acid and disulfide converts the disulfide into a material called mercaptan. Once converted completely into mercaptan, the addition of copper sulfate in very small quantity (0.05 to 0.5 milligrams per liter) removes the mercaptan from the wine. This treatment is only effective when ascorbic acid is added to the wine several days before the copper sulfate addition.
See FIVS technical papers for more information - click here.
