Cocoa Products Should be Monitored for Low-Level Toxin

August 10, 2012

Brazilian researchers found ochratoxin A contamination in 158 of 168 cocoa samples.

Cocoa experts have long known about ochratoxin A, a fungi-derived mycotoxin found at low levels in cocoa products and many other foods. Ochratoxin A grows naturally during fermentation, but species numbers can grow during preprocessing stages, such as drying and storage. Because of their latest findings, a team of Brazilian researchers is now calling for constant monitoring of ochratoxin A in cocoa and greater exploration of prevention and reduction methods.

Led by Marina Copetti of the Federal University of Santa Maria in Brazil, researchers analyzed 168 samples of cocoa product (shells, nibs, liquid, butter, cake, and cocoa powder) to measure naturally occurring ochratoxin A levels in each and to investigate how chocolate manufacturing reduces ochratoxin A presence.

Using high-performance liquid chromatography (HPLC), researchers detected some presence of ochratoxin A in nearly every cocoa product (158 out 168 products). The overall presence was considered “generally low,” but risks of human exposure to ochratoxin A-especially childhood exposure-are yet to be fully understood:

 

…chocolate-containing products are widely consumed by children who are more sensitive to the effects of mycotoxins. Thus, it is important that constant monitoring shall be carried out of their occurrence and also to find ways to prevent the contamination in the cocoa production chain.

 

Nearly 94% of ochratoxin A in cocoa was destroyed in the study when researchers followed traditional processes used to manufacture chocolate. Heating significantly reduced contamination, but shelling showed a much greater effect: 10 times more ochratoxin A was discovered in the shell as was discovered in the cocoa nibs.

Cocoa butter was the least contaminated of products (mean concentration of 0.03 μg/Kg) whereas cocoa powder was most contaminated (mean concentration of 5.13 μg/Kg)

Cocoa butter’s low contamination could mean that ochratoxin A remains in the defatted cocoa solids.

Government work is already underway to address the risk of ochratoxin A contamination in cocoa beans. The Codex Alimentarius Commission recently assigned the nation of Ghana to head a “Working Group on OTA in Cocoa” to develop a code for such practice. Once that code is developed, the Codex will consider setting a maximum level for ochratoxin A in cocoa.