A total of (213) canned food samples comprising of Tuna &Sardines,
Juices, Tomatoes pasts, Jam and Beef were randomly collected from
super stores and local markets in Tanta city from Awlad Ragab,
Fatthallah, Munshwi, Casion. Also 24 fast food samples collected from
local cafeterias and restaurants in Tanta city from Al Gaan, Abu Deshish,
Al Baraka, Abu Owaf. All canned food samples were within expiry date,
none of which is bloated, leaking and/or physically damaged. Samples
were investigated for some bacteria and fungi using specific media and
incubated for suitable incubation period. The results revealed that
species of microbes isolated in this study namely Bacillus subtilis,
Bacillus cereus, Bacillus atrophaeus., Staphylococcus saprophyticus,
Enterococcus faecalis, Staphylococcus epidermides, E. coli, Klebsiella,
Salmonella , Aspergillus niger, Penicillium notatum, Candida tropicalis
and Saccharomyces cerevisiae. Biochemical tests were performed for all
isolates to know the most common isolates (Bacillus cereus and
Aspergillus niger). Antimicrobial activities of chitosan were investigated
against the most common isolates B. cereus and A. niger. Results
revealed that chitosan has antibacterial activity towards Bacillus cereus.
The minimum inhibition concentration (MIC) for chitosan was 6.25
μg/ml with mean diameter of inhibition zone 8 mm. Also chitosan has
antifungal activity toward Aspergillus.niger with minimum inhibition
concentration (MIC) 30mg/ml and percent of fungal growth inhibition
16.7%.