Comparative Bacteriological Analysis of Fermented and Unfermented Ugba (Pentaclethra macrophylla)

Abstract

Ugba, a traditional fermented condiment produced from African oil bean seeds (Pentaclethra macrophylla), is widely consumed in southeastern Nigeria. The fermentation process enhances the sensory properties and nutritional quality of the product; however, traditional processing methods may expose the food to microbial contamination. Understanding the bacteriological differences between fermented and unfermented Ugba is therefore important for evaluating its microbiological quality and potential food safety risks. This study comparatively assessed the bacteriological characteristics of fermented and unfermented Ugba in order to determine microbial populations associated with the fermentation process. Samples of fermented Ugba and unfermented African oil bean seeds were obtained from local market vendors and analyzed using standard microbiological procedures. Serial dilution and spread plate techniques were used to determine total heterotrophic bacterial counts and coliform counts. Bacterial isolates were identified based on colonial morphology, Gram staining, motility tests, and biochemical characterization including catalase, oxidase, citrate utilization, indole, methyl red–Voges Proskauer, and coagulase tests. The results showed higher total heterotrophic bacterial counts in fermented Ugba samples (mean 4.42 log10 CFU/g) compared with unfermented samples (mean 4.01 log10 CFU/g), indicating increased microbial activity during fermentation. Coliform bacteria were detected in some samples, with fermented Ugba showing higher counts (mean 4.38 log₁₀ CFU/g) than unfermented samples (mean 3.95 log10 CFU/g). Identified bacterial isolates included Escherichia coli, Klebsiella spp., Salmonella spp., Pseudomonas spp., and Staphylococcus aureus, with E. coli occurring most frequently. The study demonstrates that fermentation increases microbial populations in Ugba while the presence of coliform and pathogenic bacteria suggests possible contamination during traditional processing. Improved hygienic practices and controlled fermentation methods are therefore recommended to enhance the microbiological safety of this widely consumed traditional food condiment.