Chemical and Microbial Quality of Pasteurized Yoghurt in the Zanjan Province in 2012 to 2014

Generally، yogurt has the highest consumption among all fermented milk products in the world and has significant nutritional value، particularly protein and calcium. Yogurt due to having higher acid، often suffer micro-organism infections resistant to acid such as molds and yeasts. But main surface spoilage in yogurt occurs by mold. The present study was done between the years 2012 to 2014 on pasteurized yogurt samples collected from 9 dairy products industry of Zanjan Province for the purpose of monitoring the quality of products. The results showed that from among 50 samples of pasteurized yogurt، all of them in terms of acidity، pH and solids-not-fat (SNF) properties were consistent with national standards. Also in investigating the total bacteria count، no infection was observed with pathogenic micro-organisms. Findings from the study showed that most of the pasteurized yogurt produced in the Province of Zanjan in terms of the quality and biological characteristics is suitable and compliant with standards.