Topic 3 Ochratoxins

Ochratoxin A commonly contaminates dry fruits

This is a 10 day time lapse movie of a grape cluster that has been infected with Botrytis cinerea (early appearing gray fungus on lower grapes), Aspergillus niger (later appearing dark black fungus on rear grapes), and Mucor sp. (white filamentous fungus in front). The images were taken at 15 minute intervals.

Ochratoxin A (OTA) is produced by several species of Aspergillus and Penicillium and is a common food-contaminating mycotoxin.

Contamination of food commodities, such as cereals and cereal products, coffee beans, dry vine fruits, wine and grape juice, spices, preserved meat and liquorice, occurs worldwide, generally as a result of poor storage of commodities and suboptimal agricultural practices during the drying of foods.

OTA widely occurs in cereals, and beer, a cereal product, has a potential contamination risk, depending on the brewing materials contamination levels. However, the brewing process reduces OTA amounts.

OTA is formed during the storage of crops and is known to cause a number of toxic effects in animal species. The most sensitive and notable effect is kidney damage, but the toxin may also have effects on fetal development and on the immune system.

Source: ACS Detecting potentially harmful mycotoxins in beer
Credit: Vaclav Mach/

Ochratoxin A in coffee, including its natural sources derived from fungal contamination of beans, their possible toxic effects in humans (black lines) and the potential treatments for minimizing its effects by reducing the fungal contamination of coffee beans (red lines).