Microbiological evaluation of ready-to-eat salads from restaurants in Zagazig City

Abstract EN

The increased consumption of ready-to-eat salads outside homes as a result of a fast paced lifestyle, awareness on their nutritional attributes and enhanced processing technology is well documented.

This study was aimed to determine the microbiological quality of two types of ready-to-eat salads (RTE) which were collected from three categories of restaurants i.e., tourist restaurants (TR), local restaurants (LR) and food vehicle (FV) in Zagazig City, Sharkia Governorate, Egypt.

Total of 60 samples representing: 24 Coleslaw salad samples (twelve in summer and twelve in winter) were collected from (TR) and (LR), and 36vegetable salad samples (eighteen in summer and eighteen in winter) were collected from (TR), (LR) and (FV).

These samples were used for detection and enumeration of Escherichia coli 0157 : H7, Salmonella spp., Shigella spp., Coliforms group, total count of bacteria and total count of yeast and moulds, using standard methods.

Homogenized salad samples were incubated in selective enrichment broths to allow the concurrent growth pathogens.

The tested microorganisms varied widely between samples for different types of restaurants and seasons.

Salmonella spp.

was found in twelve of eighteen vegetable salad samples in summer and four of eighteen samples in winter.

Shigella spp.

was found in fifteen of eighteen vegetable salad samples in summer and twelve of eighteen samples in winter.

Escherichia coli 0157 : H7 was found in fourteen of eighteen vegetable salad samples in summer and ten of eighteen samples in winter.

Shigella spp.

was found in five of twelve coleslaw salad samples in summer and three of twelve samples in winter, and Escherichia coli 0157:H7 was found in five of twelve coleslaw salad samples in summer and four of twelve samples from twelve in winter.

The average microbial counts (log10 cfu/g) of coliforms group in vegetable salads ranged from 5.08 to 6.47 in summer, and from 4.71 to 6.45 in winter.

Total count of bacteria ranged from 5.20 to 6.46 in summer, and from 3.98 to 5.84 in winter.

Total count of yeast and moulds ranged from 2.95 to 5.24 in summer and from 3.58 to 5.13 in winter season.

According to the Egyptian standard specifications for foods, these samples are unacceptable from the standpoint of microbiological safety; therefore, these data indicate that food handlers may contribute to pathogens contamination and that there are some handling practices that require more attention.