Assessment of the Microbial Load and Nutritional Profile of Street-Vended Foods at Imo State University: Implications for Public Health and Food Safety

Abstract

This study provides a comprehensive evaluation of the microbiological quality and nutritional content of nine different street-vended food items commonly consumed by students at Imo State University, Owerri. By employing both cultural and molecular identification methods, a range of bacteria associated with food spoilage and potential health concerns were identified, including Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Bacillus cereus, Corynebacterium diphtheriae, Micrococcus luteus, Klebsiella pneumoniae, Enterococcus faecalis, Proteus mirabilis, and Lactobacillus plantarum. The total heterotrophic bacterial count (THBC) varied significantly among the food items, with African salad having the highest count (3.5×10^8 CFU/ml) and soup having the lowest (0.83×10^8 CFU/ml). The highest total coliform count (TCC) was recorded for moi at 1.97×10^8 CFU/ml, while the lowest total fungal count (TFC) was observed at 6.8×10^6 CFU/ml, suggesting that effective fungal growth control measures were needed. Cooked rice had an alarmingly high total lactic acid bacterial count (TLC) of 1.9×10^9 CFU/ml, highlighting concerns regarding storage and handling practices. Temperature analyses over a 240-hour period showed a general increase, with African salads exhibiting the most significant temperature change from 22°C to 26°C, indicating the potential for increased microbial activity. The carbohydrate content analysis revealed a decrease over time, signifying active fermentation, notably with African salad starting at 9.67±3.10 g/L and decreasing to 6.12±2.03 g/L, while roasted yam decreased from 3.61±3.03 g/L to 1.130±0.03 g/L at the end of the observation period. The ash content generally increased across all food items, with African salad showing an increase from 0.33% to 0.59% over 240 hours, suggesting that mineralization processes were possibly due to microbial breakdown of organic matter. The lipid content in food samples preserved with various plants remained relatively stable, with cooked rice and stew displaying the highest mean lipid content, which slightly increased at 72 hours before plateauing. These findings are statistically significant, with a p value less than 0.05. This study underscores the need for enhanced food safety protocols and regular monitoring to ensure the health and safety of consumers, as the microbial load and nutrient content of street-vended foods are subject to significant variations influenced by environmental conditions and handling practices.