Document Type : Original
Department of Forensic Medicine, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Department of Community Medicine, School of Medicine, Razi Teaching Hospital, Guilan University of Medical Sciences, Rasht, Iran.
School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Department of Microbiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Background and objective: Traditional dairies have been produced and consumed since long time ago. However, their quality status is not routinely examined. Therefore, we determined microbial content and starch level of traditional yogurts produced in north of Iran.
Materials and methods: Detection of Coliforms and Escherichia coli (by MPN method), Staphylococcus aureus (by surface plating on Baird Parker agar) and yeast/mold (by surface plating on Dichloran Rose-Bengal Chloramphenicol Agar) were conducted. Starch inclusion was determined by addition of iodine reagent to the products and monitoring of color change.
Results and conclusion: All samples were approved in Coliforms, E. coli, and S. aureus tests. Mold was detected in five samples and the all showed yeast growth more than accepted level. According to Iranian regulation about fermented foods containing yeast as starter that exempted from maximum limit of yeast, majority of yogurts were appropriate for consumption in view of yeast contamination. Most of the samples did not contain starch except for two yogurts containing high starch. Low microbial contamination and starch content in the samples was due to the use of safe raw materials and prominence of healthy microbes present in traditional dairies in Iran.