A few years ago, the presence of ochratoxin A (OTA) was reported for the first time in wine. Grape juice is usually more contaminated than wines, and red grape products are more contaminated than white ones. This knowledge has led researchers to conclude that grape processing could contribute to a reduction in the content of this mycotoxin in grape products, such as the case of wines.
This study presents the effect of the more common vinification steps on the fate of the mycotoxin during wine making. Grapes with a content of OTA ranging from 0.43 to 7.48 μg/Kg were used for vinification. These grapes were obtained by inoculating recently harvested grapes with an ochratoxin A producing Aspergillus. It was found that after alcoholic fermentation just about 31.8% of the OTA initially present in grapes remained in the wine. After racking, this amount decreased to 10.9 %, and, after malolactic fermentation, to 8.1%. Also, it was found that OTA was present in higher amounts in spent fractions from wine making, such as the lees obtained after fermentation or the sediment obtained after racking. After malolactic fermentation, the most common eonological fining agents were able to decrease even more the content of OTA in the final wine. Vinification assays with eonological enzymes commonly used in wine making industry were also done.
Based on this data, we concluded that this reduction is associated with the mycotoxin removal by adsorption into solid wastes or fining agents, and not due to any degradation of ochratoxin A into other compounds.
Publication Type: Abstracts in Conference Proceedings