Polycyclic aromatic hydrocarbons in coconut kernel products

Abstract

Eighty seven samples of coconut kernel products from Sri Lanka dried in the sun, in direct heating kilns, and in indirect heating kilns were examined for polycyclic aromatic hydrocarbons (PAH) formed by combustion and thermal decomposition of organic substances in coconut shells. Analysis was done by the extraction of organic matter in dichloromethane followed by purification and quantification of PAH by HPLC using a fluorescent detector. The mean total PAH concentration in copra, coconut oil, copra meal and parings were 102 ± 184, 359 ± 412, 68 ± 101 and 109 ± 164 μg/kg respectively. Some of the sun-dried copra samples did not contain any detectable PAH. Comparatively low PAH concentrations observed in Sri Lankan coconut kernel products were thought to be due to controlled combustion of shells with excess of air during drying of copra effected through the Standard Ceylon Copra Kiln which provides a relatively clean supply of hot air.