Abstract

*Doughari J. H, Alabi G. and Elmahmood A. M

The effect of some commonly used chemical preservatives (benzoic acid, sodium benzoate and sodium sulfite) on the shelf-life of Sobo drink was investigated by isolation of microorganisms before and during its ambient storage for 14 days. Three bacterial species, i.e. Lactobacillus acidophilus, Bacillus subtilis and Bacillus cereus were isolated. L. acidophilus was found only in the samples without preservatives, while B. subtilis and B. cereus were found in the samples with preservatives. Four fungal species, i.e. Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus and Trichoderma sp. were isolated. Trichoderma sp. was isolated only in the samples without preservatives, while A. niger, A. flavus, A. fumigatus were isolated in samples with preservatives. Antimicrobial activities of the chemical preservatives revealed that benzoic acid was the most effective against both bacterial and fungal species, followed by sodium benzoate and sodium sulfite. Of all the samples, only those treated with benzoic acid as preservative remained organoleptically attractive after preservation for 14 days.