Assessment of microbiological quality and heavy metal content in palm oil sold at selected markets in Bayelsa State

Abstract

This study assessed the heavy metal burden and microbial load of palm and the microbiological safety of palm oil sold in Zarama, Elebele and Tombia markets in Bayelsa State Nigeria. Heavy metal was analysed using an atomic absorption spectrophotometer. Bacteria and fungi were isolated and identified based on their cultural, morphological and biochemical characteristics. The Total viable count (cfu ml-1) of the samples ranged from 24 x 106cfu/ml to 55 x 106cfu/ml with samples obtained from the Elebele market having the highest, while samples from the Tombia market had the least. The microbial contaminants isolated were Escherichia coli, Pseudomonas sp Klebsiella sp, Bacillus sp, Proteus sp, Staphylococcus aureus, Aspergililussp, Mucor sp Rhizopus sp, Penicillium sp. Bacillus sp had the highest frequency of occurrence of 28.6% followed by Aspergillus sp and, Mucor sp (22.2%), while Escherichia coli, and Klebsiella sp had the lowest (7.1%). All the tested metals were detected in the samples from Tombia and Elebele Markets. Zn concentrations were highest in Zarama with 0.25±0.01 while it was low in the Elebele market respectively. Cu was found to be highest in Zarama, having 2.47±0.05 as its concentration but very low in Elebele with a concentration of 0.01 respectively. Tombia recorded the highest concentration of Cd with 0.34±0.02 and Pb with 0.4±0.01 while Pb was not detected in Zarama. The majority of the microorganisms found in the oil are pathogenic to humans. However, most of the heavy metals assayed for were above acceptable limits.