Cyanide Content of Commercial Gari from Different Areas of Ekiti State, Nigeria

Abstract

Gari, a creamy-white granular flour made from fresh cassava tubers have been known to contain residual cyanide (hydrocyanic acid) after processing. Cyanide is poisonous and ingestion of Gari beyond the permissible limit can lead to chronic toxicity. This study therefore investigated the presence of this chemical in Gari samples taken from different areas of Ekiti State in Nigeria to ascertain whether or not they are below the permissible level. Random samples of commercial Gari processed locally were collected from 6 areas of Ekiti State in South West Nigeria and screened for residual cyanide content. The alkaline picrate method was used for the screening. Four of the samples contained cyanide in the range of 2.10-9.10 mgHCN/kg which falls below the permissible limit while the remaining two samples had higher residual cyanide of 11.78 and 15.30mgHCN/kg which is above the permissible limit. WHO permissible limit of cyanide concentration is 10.0mgHCN/kg. The samples with concentration above 10mgHCN/kg are from areas where the cassava mash was fermented for less than 12 hours.

Keywords: Gari, cyanide, permissible limit, alkaline picrate method