Investigation of Chemical and Microbiological Quality of Yoghurts Marketed in Bilecik Province

In this study, some chemical and microbiological traits of 30 yoghurt samples marketed in local markets in Bilecik province were investigated. The pH, acitidity, fat, dry-matter, protein, ash, syneresis and peroxidase contents of yoghurts samples were 3.84-4.80, 0.72-1.17%, 3.00-4.20%, 11.25-16.05%, 2.65-4.21%, 0.63-1.14%, 5.00-11.50 ml/25 g, respectively while peroxidase test was negative. Total aerobic mesophilic bacteria, coliform bacteria, Enterobacteriaceae, total aerobic mesophilic psychrotrophic bacteria, mould and yeasts and lactic acid bacteria contents of yoghurts samples were 5.08-9.19 log kob/g, 1.00-2.08 log kob/g, 1.00-3.96 log kob/g, 1.55-5.53 log kob/g, 1.00-5.87 log kob/g, 5.08-7.98 log kob/g, respectively. According to Yoghurt Standard of Turkish Standards Institution and Regulations of Fermented Milk of Turkish Food Codex, the analysed samples were not appropriate based on dry-matter, acidity and coliform bacteria as 1 (3.33%), mould and yeasts as 10 (66.67%) and protein as 7 (23.33%).