LAUSR

Abstract The objectives of this study were to investigate the microbial contamination level and composition in the cold storage room and on the contact surface in domestic refrigerators. Different levels of bacteria (1–27 CFU/vessel) and fungi (0–22 CFU/vessel) were found. The PM 2.5 values, ranging from 0 to 122 μg/m3, were found to correlate with total bacterial count. The number of total bacteria, psychotropic bacteria, fungi and coliforms on the internal contact surfaces was 3.18–7.82 log CFU/100 cm2, 2.37–8.13 log CFU/100 cm2, 3.57–7.46 log CFU/100 cm2 and 0.35–4.60 log MPN/100 cm2, respectively. These results indicated that the presence of different types and levels of microorganisms. For bacteria, Bacillus and Acinetobacter were the predominant genus, and were present in 100% and 87.5% of the refrigerators. Enterococcus, Citrobacter, Exiguobacterium, Staphylococcus, Enterobacter and Pseudomonas were also detected in some refrigerators. For fungi, Saccharomyces and Candida were the most predominant genus in 75% of the refrigerators, while Malassezia, Schwanniomyces and Kazachstania were also found in some refrigerators. This study provided the information of microbial contamination, suggesting the need to regularly clean and disinfect domestic refrigerators.