Microbiological quality of commercial mayonnaise sold in Assiut city

Abstract: A total of 30 random samples of commercial mayonnaise were collected from different retailer is Assiut city. To assess their quality, the samples were examined microbiologically for the incidence and counts of aerobic plate count (APC), psychrotrophs, thermoduric, enterococci, colifrms, fecal coliforms, Escherichia coli, Bacillus cereus, Staphyococcus aureus, anaerobes and yeasts & molds. The obtained results verify that total bacterrial, psychrotrophs, thermoduric and enterococci counts averaged 3x104, 1.7x103, 2.7x104 and 2.9x103/g of the examined mayonnaise samples, respectively. B. cereus could by isolated from 20% in numbers averaged 1x103/g of the examined mayonnaise samples. Yeasts & molds contaminated 26.67% of the examined mayonnaise sample Yeasts in numbers averaged 2.2x102/g of the samples. All the examined mayonnaise samples failed to yield coliforms ( less than 3/g) and therefore fecal colifrms and E.coli could not be recovered from the examined samples.Also,S.aureus and anaerbes could not be detected in any of mayonnaise samples examined. The results prove that the examined commercial mayonnaise samples sold in Assiut city are of quite good quality and considered as microbilologically safe products Although the microbial loads are below the hazard point, the health hazard of such microorganisms still exists if they are allowed to grow and multiply, and that what was studied through the second part of the present study, in which the survival and viability of Salmonella typhimurium, Escherichia coli O157:H7, Listeria monocytogenes, Staphyococcus aureus and Bacillus cereus in commercial mayonnaise kept at room temperature were studied. Each mayonnaise sample was inoculated separately with one of the mentioned pathogenic microorganisms and then incubated at room temperature ( about 25oC) as commercial mayonnaise is usually distributed, shelved and stored at this temperature. After that, the inoculated mayonnaise was sampled after 6, 24, 48 and 72 hours. The results revealed the lethal effect of mayonnaise on the inoculated microorganisms although the survival and viability of L.monocytogenes and B. cereus was relatively longer than others. Suggestive hygienic measures for improving the quality of mayonnaise and also to safeguard the consumer were discussed.
Publication year 2007
Pages 138 : 151
Availability location مكتبة معهد بحوث صحة الحيوان
Availability number
Organization Name
City اسيوط
serial title مجلة أسيوط الطبيبة البيطرية – المجلد ( 53) – أبريل 2007- العدد ( 113 ) – من صفحة 138 : 151
Author(s) from ARC
Agris Categories Animal diseases
Publication Type Journal