Increasing consumption of chocolate with high levels of cocoa could “elevate exposure” to food contaminants aflatoxins and ochratoxin A, according to researchers, although they acknowledged it remains a "minor source".
Concentrations of aflatoxins and ochratoxin A found in cocoa currently equate to low human exposure risks, however changing consumption habits could present problems and high chocolate consumption by children was highlighted as an area of concern.
“Chocolate appears to be a minor source of ochratoxin A and aflatoxins in the diet, although the fact that products containing chocolate are widely consumed by children is a concern, so monitoring of their occurrence in these products is important,” the researchers concluded.
The Brazilian study looked at the development of fungi and mycotoxins in cocoa from the raw material to final production, finding agricultural practices had a significant influence on the development of these toxic moulds.
From farm to bar
The research, published in the International Journal of Food Microbiology, suggested the prevention of mycotoxins was the best approach.
“Mycotoxins are stable compounds in storage, and are more or less resistant to chemical and physical treatments, so the best approach to limiting mycotoxin contamination in foods is reduction of formation,” they wrote.
Looking at cocoa produced in the Ivory Coast, they said the main formation of ochratoxin A tended to start between harvest and fermentation, particularly with small holders, when pods were damaged leading to the accumulation of the mould toxins.
It was recommended that producers keep pods as free from mould as possible, separating infected pods from the rest straight away and harvesting healthy pods as soon as possible.
The researchers pointed to earlier Brazilian studies that showed the importance of organic acids, especially acetic acid, produced by fermentative bacteria in suppressing the growth of fungi.
They also advised drying the beans immediately and quickly.
Source: International Journal of Food Microbiology
Vol. 178, Iss.16 May 2014, pp. 13–20, http://dx.doi.org/10.1016/j.ijfoodmicro.2014.02.023
“Fungi and mycotoxins in cocoa: From farm to chocolate”
Authors: M. V. Copetti, B. T. Iamanaka, J. I. Pitt, M. H. Taniwaki