Document Type : Original Article


Agric. Microbiol. Dept., Fac. Agric., Zagazig Univ., Egypt


The safety of ready-to-eat foods is an important topic in today's life. Improper handling of ready-to-eat food items may result in foodborne outbreaks. In this study, koshari, vegetable salad and couscous were selected as the target ready-to-eat foods for a microbiological survey. The aim of this study was to evaluate the microbiological quality of koshari, vegetable salad and couscous sold in Zagazig shops in Sharkia Governorate. A total of 39 samples were collected from food stores in winter and summer seasons. They were tested for the presence of pathogenic microorganisms causing food poisoning (Salmonella spp., Shigella spp., enterococci and staphylococci), spoilage microorganisms (fungi and yeasts), total aerobic viable counts, lactic acid bacteria and coliform groups. The study also aimed to monitor the population changes of the previous microbial groups during the storage of these foods at refrigerator temperature (5 – 7ºC) and abuse conditions of room temperature (22±2 ºC) . By comparing the three tested foods, generally vegetable salad had the highest microbial populations, followed by koshari, then couscous. The numbers of Salmonella and Shigella were 6.15, 5.47and 4.89 log cfu/g in summer for vegetable salad, koshari and couscous, respectively. Also, the average microbial counts in summer are clearly higher than those in winter. Generally, the microbial numbers kept increasing for several days, then started to decrease. For most microbial groups, the peak of their numbers were at days 5, 3-5 and 6-8 for koshari, vegetable salad and couscous, respectively. By looking at microbial numbers changes in vegetable salad stored in refrigerator, enterococci increased up to 2.26 log cfu/g after 5 days, staphylococci increased up to 0.12 log cfu/g after 1 day, coliforms increased up to 0.77 log cfu/g after 3 days and Salmonella and Shigella  increased  up to 0.45 log cfu/g after 2 days. All of these groups started to decrease thereafter. Based on the current results, it is higher recommended to follow routine inspections and training of vendors to improve the microbiological quality of food products.