Isolation And Identification Of Fungi From Packaged And Unpackaged Powdered Milk, Corn Flour And Soybean Flour

This research was carried out for the isolation and identification of fungal spoilage organisms in foods. The foods studied are, packaged and unpackaged powdered milk, corn flour and soybean flour. These samples were bought from Enugu main market (Ogbete) using sterile nylon bags for each samples and taken to the laboratory for analysis. One gram of each sample was put into nine (9) ml of sterile water, tenfold dilution was carried out upto the fithth  srerile test tubes to reduce microbial load. Spread plate method was used by taking 0.1 from each dilution unto sterile prepared Sabouraud dextrose agar plates, the plates were incubated atleast for 48hrs for growth to occur. Representative growths from the plates were then sub cultured on agar slant to obtain pure cultures for identification.

Slide culture technique was use for proper identification of the filamentous fungi and incubation was at least four (4) - six (6) days. Lactophenol blue was use to stain the fungi growth on the slide and the cover slip which was viewed under the light microscope. From this research carried out genera of fungi isolated  were, Aspergillus, Fusarium, Pennicillium and Mucor. The dominant genus isolated was Aspergillus. The most contaminated food product from this research is the corn flour sample which was contaminated with all the fungal genera identified. 

The fungi isolated are known to be pathogens of man some species of aspergillus are known to produce toxins which is the aflatoxin causing the diseases known as aflatoxycosis in man. Also some species of penicillium and fusarium are known to produce mycotoxins which causes human diseases. These food products can be contaminated due to daily exposure to air as fungi spores are known to be present in large number in the air making it easy for them to invade exposed foods