A simple chemical method reduces ochratoxin A in contaminated cocoa shells

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium species, which contaminates cocoa among other food commodities. It has been previously demonstrated that the toxin is concentrated in cocoa shells. The aim of this study was to assay a simple chemical method for ochratoxin A reduction from naturally contaminated cocoa shells. In order to determine the efficiency of the method, a high-performance liquid chromatography method with fluorescence detection was set up beforehand and validated. Ochratoxin A was extracted from cocoa shells with methanol-3% sodium bicarbonate solution and then purified with immunoaffinity columns. The recovery attained was 88.7% (relative standard deviation = 6.36%) and the limits of detection and quantification were 0.06 and 0.2 kg/kg, respectively. For decontamination experiments, the solvent extractor ASE 200 was used. First, aqueous solutions of 2% sodium bicarbonate and potassium carbonate were compared under the same conditions (1,500 lb/in2 at 40 degrees C for 10 min). Higher ochratoxin A reduction was obtained with potassium carbonate (83 versus 27%). Then, this salt was used under different conditions of pressure, temperature, and time. The greatest ochratoxin A reduction was achieved with an aqueous potassium carbonate solution (2%), at 1,000 lb/in2 at 90 degrees C for 10 min. This method could probably be applicable to the cocoa industry because it is fast and relatively economic. From the point of view of human health, the use of potassium carbonate, partially eliminated by rinsing the sample with water, does not likely represent a risk for human health.