Evaluation of microbiological quality of sushi sold in restaurants and supermarkets in turkey

Sushi is a popular traditional Japanese food in worldwide. This study was conducted to investigate the physical, chemical, sensory and microbiological quality of sushi sold in supermarket and restaurants. 300 sushi samples were purchased from 5 different popular restaurants (A, B, D, E, and F) and 1 supermarket (C). Four main types of sushi (California roll (CR), sesame roll (SMR), sake roll (SR), take roll (TR)) were chosen from each station. pH values of sushi rice samples were found to be all below 4.6. According to sensory overall quality of sushi samples, CR and SMR from station C had significantly the lowest values (p<0.05). Among the sushi samples, pathogenic bacteria Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus were not detected in 25 g portion of any samples. Counts of total aerobic bacteria were high in stations A, B, D, E, and F (between 4.3-7 log CFU/g), except for station C (3.5 log CFU/g). Results for coliform counts showed similar trends as those of E. coli counts in samples. E. coli counts of all sushi types from all stations (except SMR, SR and TR from station D and SR from station E) exceeded the limit of acceptability (<100 MPN/g). Our finding may suggest a common presence of coliforms and E. coli in raw materials used in sushi preparation.