Ochratoxin A:from grapes to wine

Prevention of ochratoxin A (OTA) accumulation through pre-harvest management is the best method to control mycotoxin contamination; however, the contamination should occur, so the hazards associated with the toxin must be managed through post-harvest procedures. The assignment of CCPs is important to make HACCP effective and is essential to prevent or to eliminate a food safety hazard or to reduce it to an acceptable level. Grapes selection is a preventive measure and the good manufacture practices in winemaking can work as corrective action for reducing contamination. According to all the experiments that were conducted under “Wine-Ochra Risk” the results show that no OTA is produced during winemaking, but each operation during winemaking can modify OTA content. OTA passes from grapes into the juice during crushing, the maceration increases OTA content, the alcoholic and malo-lactic fermentation cause an OTA reduction. During all clarification steps (either natural sedimentation or by the use of adjuvant), the level of ochratoxin A decreases because of its adsorption into the sediment. The ochratoxin A reduction due to the natural sedimentation is small, while the decrease due to the use of adjuvant depends on the type and amount of adjuvant. In order to manage the hazard of OTA in winemaking and to verify if OTA content in wine is lower than the legal limit of 2 ug/L, it would be enough to analyze OTA in must and in wine at the end of alcoholic fermentation, since the following steps cause the OTA reduction. According to the results, it is expected that a significant decrease in ochratoxin A concentration occur from grape at harvest to wine if the following good manufacture practices are achieved: • Minimize the time interval between harvest and crushing; refrigerate the grapes when crushing will not take place in a short time • Discard bunches with visible mould grown (specially black moulds) • Add sulphur dioxide to grapes • Control OTA level in must after crushing • In case of high OTA risk, reduce the maceration time, use yeast, lactic acid bacteria, and chemical adjuvants proven to be effective against OTA.