Effect of Drying and Salting on the Microbial Communities Found in Locust Beans and Fresh Fish

Locust beans (Parkia biglobosa) and fresh fish are among the most widely consumed protein sources in Africa, providing essential nutrients for both rural and urban populations. However, these food products are highly perishable and susceptible to microbial contamination, which can compromise food safety and quality. This study investigated the effect of drying and salting on the microbial communities associated with locust beans and fresh fish, with the aim of assessing their impact on food safety and preservation. Samples were collected from Owode Market in Offa, Kwara State, Nigeria, and subjected to microbiological analysis using Nutrient Agar (NA) and Potato Dextrose Agar (PDA). Serial dilution and pour plate methods were employed to determine bacterial and fungal loads, while pH, moisture content, and titratable acidity were also measured to evaluate physicochemical characteristics.
The results revealed high microbial counts in both locust bean and fish samples, with mean bacterial counts ranging from 15.1 × 10⁶ to 19.2 × 10⁵ cfu/ml and fungal counts from 7.0 × 10⁶ to 15.4 × 10⁵ cfu/ml. Biochemical and cultural characterization indicated the presence of diverse microbial species, including both bacterial and fungal contaminants. Physicochemical analysis showed moisture contents of 26.76% and 18.79%, pH values of 7.1 and 5.12, and titratable acidities of 0.017 ml and 0.61 ml for locust beans and fish, respectively. These findings suggest that both products are prone to microbial growth due to favorable environmental and compositional factors.