The study – published in Food chemistry – assessed the natural occurrence of contamination from the mycotoxin ochratoxin A in samples of cocoa and chocolate products from various stages of the chocolate production process.
“In the last decade concern has increased about human exposure to ochratoxin A, a possible carcinogen to humans, and consequently the interest in studies evaluating the sources of this contaminant in the diet,” reported the authors – led by Dr Marina Copetti from the Universidade Federal de Santa Maria, Brazil.
Previous research from the group had found aflatoxins to be present in 80% of all chocolate examined, with ochratoxin A found in 98% of the 125 samples of chocolate products. In the previous research, the team called for continuous monitoring of both ochratoxin and aflatoxin in the chocolate production process “to guarantee a safe consumption of chocolate”.
As a result, the team now reports the analysis of 168 samples of different fractions from the cocoa and chocolate production process – including samples of shell, nibs, liquor, butter, cake and cocoa powder.
Copetti and her co-workers reveal the highest levels of ochratoxin A were found in the shell, cocoa powder and cocoa cake.
“The cocoa butter was the least contaminated, showing that ochratoxin A seems to remain in the defatted cocoa solids,” said Copetti and colleagues, who added that further analysis showed 93.6% of ochratoxin A present in cocoa beans at the start of the process was reduced during chocolate production.
The analysis of 168 samples revealed a ‘widespread and low contamination’ of cocoa products by ochratoxin A.
The team revealed a tendency for higher amounts of ochratoxin A in cocoa solids, noting that shelling was the main process responsible for reduction of the contaminant in the chocolate producti9on process.
“About 93.6% of the ochratoxin A was reduced during the chocolate making process,” they revealed.
Copetti and her team say that when the amounts of ochratoxin A found in cocoa products is considered and applied to the production of chocolate powders, cakes, biscuits and similar products, “it is concluded that cocoa does not represent a major source of ochratoxin A in the diet.”
Despite such conclusions, the researchers reiterate their previous calls for constant monitoring to be carried out in the cocoa production process. They also suggest further research efforts for find ways of preventing such contamination in the cocoa production chain.
Source: Food Chemistry
Published online ahead of print, doi: 10.1016/j.foodchem.2012.07.093
“Occurrence of ochratoxin A in cocoa by-products and determination of its reduction during chocolate manufacture”
Authors: Marina V. Copetti, Beatriz T. Iamanaka, Melanie A. Nester, Priscilla Efraim, Marta H. Taniwaki