Sampling of Cocoa Beans and Quantification of Ochratoxin A: Validation of the Methods

A. Coulibaly; A. Dembele; K. Bohoussou; A. Toure; G. H. Biego

A. Coulibaly Training and Research Unit of Biological Sciences, Peleforo Gon Coulibaly University, BP 1328 Korhogo, C�te d'Ivoire.
A. Dembele Central Laboratory of Agrochemistry and Ecotoxicology, LANADA, 04 BP 612 Abidjan 04, Cote d'Ivoire.
K. Bohoussou Laboratory of Biochemistry and Food Science, UFR Biosciences, Universit� Felix Houphouet-Boigny, 22 BP 582 Abidjan 22, Cote d'Ivoire.
A. Toure Department of Environment and Health, Institut Pasteur de Cote d'Ivoire, BP V 34 Abidjan, Cote d'Ivoire.
G. H. Biego Laboratory of Biochemistry and Food Science, UFR Biosciences, Felix HOUPHOU�T-BOIGNY University of Abidjan, 22 P.O. 582 Abidjan 22, C�te d'Ivoire.

Keywords: Ochratoxin A, cocoa bean, sampling validation method, merchantability

Abstract

The objectives of this study were compare an alternative method for cocoa beans sampling with the standard method proposed by the European Union (EC 401/2006) and validate a method of Ochratoxin A determination. The alternative method applies to samples of 5 kg of cocoa beans while the standard method applies to samples of 10 kg. quality characteristics and validation parameters were determined according to Ivorian Coffee and Cocoa stock exchange and French (NFV03-110-1998) standards. Concerning quality characteristics, no significant difference at 5% risk was revealed in the values of the three parameters considered when assessing marketability quality requirements (moisture, graining and grades). As regards the validation of OTA determination method, the limits of detections and quantifications were 0.05 g/kg and 0.20 g/kg. The coefficients of variation for the tests of repeatability and reproducibility were respectively 0.26% and 5.67%. As for the extraction yield, it was equal to 86%. Furthermore, no significant difference (5% risk) was observed between the concentrations of OTA measured by the standard and alternative methods. Hence, although the alternative method goes with a mass reduction of samples analyzed, it did not alter significantly the results of the marketability as well as the concentrations of OTA.