Microbiological quality of ready to eat coleslaw marketed in Ibadan, Oyo-State, Nigeria

Abstract

This study assessed the microbiological quality of coleslaw samples sold at restaurants in Ibadan, Oyo-state, Nigeria. Three hundred and sixty samples were analyzed over a 12-week period for aerobic mesophilic counts, psychrotrophic counts, levels of Enterobacteriaceae, yeasts and molds, total lactic acid bacteria and total anaerobes. The coleslaw samples were also analyzed for presumptive L. monocytogenes and Salmonella spp. Counts of up to 9.2, 8.2, 9.4, 9.0, 8.7, and 8.9 log CFU/g for aerobic mesophilic organisms, psychrotrophic counts, Enterobacteriaceae, yeasts and molds, total lactic acid bacteria and total anaerobes, respectively, were recovered from the coleslaw samples. Despite high counts of yeasts and molds and LAB (up to 9 and 8.7 log CFU/g, respectively) recovered from some samples, no visible spoilage was detected. The levels of microorganisms recovered from the coleslaw samples at different sample collection time (week 1–12) were significantly (P < 0.05) different for each restaurant. Similarly, microbial levels recovered from coleslaw samples collected from different restaurants differed significantly (P < 0.05) from one restaurant to the other. Thirty (30.5%) and 24.7% of the coleslaw samples were positive for presumptive L. monocytogenes and Salmonella, respectively, an indication of potential threats to food safety in the area. The study concluded that the roles of yeasts and molds, as well as LAB in the spoilage of coleslaw sold in the study area, need to be further investigated. Public health intervention strategies to enhance microbiological safety of RTE coleslaw are required in the city.