Assessment of bacterial quality of some fruits sold in selected markets within Kaduna metropolis

Abstract

Microorganisms are known to contaminate or destroy fruits there by reducing the quality and the profits derived from them. Consumption of raw fruits often lead to food related disease outbreaks. The purpose of the study was to isolate, and identify bacteria present in fruits that are commonly sold in three different markets within Kaduna metropolis. A total of 54 different fruit samples of avocados, apples, and Sour sops were purchased from Bakin Dogo, Station and Kawo markets. All samples were analyzed for the density of microorganisms present using standard plate count method. The frequency of occurrence of the different types of bacteria present on the fruit samples were also determined using standard microbiological methods. The composition of nutrient in each fruit sample was also analyzed using standard method. The results of the study showed that the microbial loads of all the fruits examined ranged between 1.02 x 10⁵ ± 0.60 x 10⁵ CFU/ml to 1.38x10⁵ ± 0.30x10⁵ CFU/ml and the differences were found to be significant (P < 0.05). The sour sops obtained from Bakin dogo market had the highest mean microbial load of 1.38x10⁵ ± 0.30x10⁵ CFU/ml, followed by Avocado (1.24 x 10⁵ ± 0.07 x 10⁵ cfu/ml) from Kawo. The least microbial load of 1.02x10⁵ ± 0.60 x 10⁵ CFU/ml was each for apples obtained from Bakin dogo and Station markets respectively. The species of bacteria isolated from the fruit samples were Bacillus, Pseudomonas, Staphylococcus, Streptococcus, Escherichia coli, and Salmonella. Of the 81(100 %) total isolates of bacteria the most frequently isolated species were Staphylococcus (35.8 %) followed by Bacillus, Streptococcus and Escherichia coli (29.2, 16,0 and 9.9 %) while the least frequently isolated species were Pseudomonas (6.2 %) and Salmonella (2.6 %). Soursop has high ash, fiber, protein and carbohydrate contents while avocado has high fat content. Reduction of risk for illnesses associated with fruit consumption can be achieved by adequate microbiological knowledge of fruits, and adopting proper hygienic ways of harvesting, processing, handling and storage.