Extent of Microbial Contamination of Refined and Unrefined Vegetable oils sold in South-west Nigeria

Abstract

Oils constitute a major source of plant-based protein. A major limitation to optimal oil consumption in sub-tropical region is fungal infestation and consequent mycotoxin contamination. Ten refined and eight unrefined vegetable oils were randomly purchase from open markets and screened for microbial contamination using standard microbial procedures. Twenty six fungi isolates were obtained from the vegetable oil samples, the isolates were identified as Aspergillus fumigatus (43.0%), Mucor (17.9%), Saccharomyces cerevisiae (10.7%), Aspergillus niger (7.1%), Aspergillus flavus (7.1%), Penicillium spp (7.1%), Aspergillus oryzae (3.6%), Mucor (17.9%) and Rhizopus spp (3.6%). Five out of the ten refined vegetable oil samples had no fungal contamination. A. flavus and A. oryzae were absent in all the refined oil samples while A. niger was absent in all the unrefined oil samples. Isolation of mycotoxigenic fungi such as Aspergillus spp. is of vital importance in the food industry. Education and training of processors and consumers is recommended.

Keywords

• Refined vegetable Oil
• Unrefined vegetable Oil
• Fungal infestation
• mycotoxigenic fungi