Abstract

The study was aimed at evaluating the microbial spoilage of selected Nigerian fermented and unfermented foods. A total of four fermented and unfermented food samples were used for this investigation. Microbial and sensory evaluations of the food products during storage were carried out using standard procedures. During storage, the bacteria counts were observed to range from 2.2 × 10⁵ to 4.8 × 10⁵ CFU/mL and from 2.5 × 10³ to 5.0 × 10⁴ CFU/mL, for the unfermented and fermented food products, respectively. Similarly, the fungal counts ranged from 1.8 × 10³ to 2.9 × 10³ CFU/mL and from 0 to 5.70 × 10³ CFU/mL for the unfermented and fermented food samples, respectively. Klebsiella aerogenes, Lactobacillus plantarum, Leuconostoc sp., Micrococcus varians, Proteus mirabilis, Streptococcus faecalis, Staphylococcus epidermidis, Aspergillus niger, Aspergillus flavus, Cladosporium herbarum, Geotrichum candidum, Mucor mucedo, Neurospora sitophilia and Penicillium sp. bacteria and fungi that were recovered from the food samples during storage. The sensory evaluation of the food products showed the fermented ones being more acceptable to panelists than the unfermented ones. This could indicate that the palatability of the fermented food samples only experienced slight or no changes during storage, when compared to the unfermented ones.

Key words: Fermented food, unfermented food, microbial spoilage.