Evaluation of Polycyclic Aromatic Hydrocarbons (PAHs) in Cocoa Beans obtained from Selected Cocoa Producing States in Nigeria

Abstract

Aims: To assess the level of Polycyclic aromatic hydrocarbons in cocoa beans obtained from selected cocoa producing areas of Cross River and Ondo States, Nigeria. Study Design: Sun-dried cocoa beans were collected from cocoa farmers in the studied areas. Place and Duration of Study: Samples were collected in Boki-Biakwan, Ikom, Etung and Efraya in Cross River; Idanre, Akure and Ile-Oluji in Ondo State between January and March, 2013. Methodology: Collected cocoa beans were ground with ceramic mortar and pestle. one gram (1 g) of each sample was extracted with hexane : dichloromethane in a ratio of 3:1. The extract was cleaned-up in a chromatographic column filled with silica gel and eluted with methylene chloride after which HP 5890II Gas chromatograph was used for the analysis. Results: Among the 16 priority PAHs detected in the samples, Dibenzo[ah]anthracene had the lowest concentration ranging from 7E-06 to 5.8E-05 µg kg-1 and 7E-06 to 5.8E-05 µg kg-1 in Cross River and Ondo State respectively while fluoranthene had the highest concentration (mean = 0.1989 µg kg-1) in samples from Cross River while anthracene had the highest concentration (mean = 0.2385 µg kg-1) in samples from Ondo State. Conclusion: The levels of Benzo [a] pyrene and PAH4 in the studied cocoa beans were far lower than the maximum level set by the European Union for PAHs in cocoa.