Microbiological analysis of fresh and processed button mushrooms

Abstract

Button mushrooms (Agaricus bisporus) are among the most widely cultivated and consumed edible fungi in the world. It is prized for their culinary adaptability and nutritional value. It is as a rich source of vitamin B-complex, essential minerals such as selenium and potassium, and dietary fibers. However, their high moisture content (80 to 90%) predisposes them to rapid spoilage by enzymatic browning and textural degradation. Given their limited post-harvest shelf life, microbiological quality analysis is critical for food safety. The microbiological assessment encompassed aerobic plate count, yeast and mold count, Enterobacteriaceae levels, detection of key foodborne pathogens, namely Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7 and Vibrio cholerae. In the present study, the aerobic plate count and Enterobacteriaceae count revealed highest values in tray-packed mushroom followed by fresh mushroom. In other samples, the load was below permissible limits. Yeast and mold count was reported only in tray packed mushroom. Pathogenic microorganisms (E. coli O157:H7, S. aureus, Salmonella spp., L. monocytogenes, and V. cholera) in both fresh and processed mushrooms were not detected. These findings highlight the influence of processing techniques on microbial contamination levels in button mushrooms. While the absence of major food-borne pathogens suggests microbiological safety, the elevated microbial loads in certain samples emphasize on up-gradation of handling techniques and storage practices to maintain better quality and prolong shelf life.