Ochratoxin A removal in wine: A review

Ochratoxin A (OTA) is a mycotoxin mainly produced in wine grapes by Aspergillus carbonarius fungal species. This mycotoxin is a potent nephrotoxin with immunosuppressive, teratogenic and carcinogenic properties and has been classified as a possible carcinogen to humans. Reports on OTA in wine revealed that its occurrence is worldwide and that red wine generally contains a higher OTA amount than white and rosé wine. The European Commission sets in 2005 the limit of OTA in wine at 2 μg/l. In the world trade the wine is an important beverage and the OTA presence in it could represent a risk to the wine economy. In this paper the physical, chemical and microbiological methods employed for the purpose of removal OTA in wine are reviewed. Among the several physical methods that may be applied, the dilution with non contaminated food-stuffs is forbidden in the European Union. The OTA may be practically reduced through the remove of mouldy grapes or bunches before entering in the winemaking process, but sometimes this may not be economically feasible for the wine industry. Chemical methods are the most widely used to remove OTA in wine. Several oenological fining agents have been tested with different degrees of success, depending on the fining agent used, its type and dosage applied, as well as the OTA concentration in the wine. Allergen free and non toxic biodegradable chitin adsorbents are good alternatives to reduce OTA in wine in comparison with the most widely adsorbents used in the winemaking process. Microbiological methods may be a good alternative to OTA detoxification in wines. The OTA degradation by microbiological methods has not been yet achieved, though it is known that can be adsorbed by some yeast and bacteria strains.