微生物および生化学技術ジャーナル

概要

Microbiological Quality of Household Refrigerators in Three Cities South-West of Nigeria

Flora Oluwafemi, Sarah Akpoguma, Taiwo Oladiran and Adelodun Kolapo

Household refrigerators are a potential source of pathogen contamination for foods leading to food spoilage and food borne diseases. This study was carried out to examine the consumers’ knowledge and hygiene status of household refrigerators in Ibadan, Lagos and Abeokuta. One hundred and eighty households were randomly selected. Questionnaires covering social demographic characteristics, refrigerator quality and maintenance practices, householders’ knowledge about food borne diseases, and frequency of electricity supply were administered. The interior of each refrigerator was swabbed using a sterile swab stick that had been pre-soaked in peptone diluent. Each sample collected was plated out on four different culture media viz. Nutrient agar, MacConkey agar, Mannitol Salt agar and Potato Dextrose agar. Results showed that majority of the householders had good knowledge of food borne disease, powered their refrigerators with generators and have some levels of education. Some refrigerators were completely free from contamination (neither bacteria nor fungi was detected) while others were found to be contaminated. Total viable count of bacteria ranged between 0 and 14.1 × 106 cfu/ml while fungi count ranged from 0 to 6.8× 106 cfu/ml. Bacteria and fungi isolated from the refrigerators were Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Enterobacter spp., Klebsiella spp. and Shigella spp., Aspergillus flavus, A. niger, A. fumigatus, Saccharomyces cerevisae and Rhizopus spp. Findings show the presence of microorganisms which can cause food spoilage and food borne diseases. Educational programmes are needed to improve the refrigeration practices and the issue of regular supply of electricity is paramount in the hygiene of refrigerators.