Roya Rouhi1, Mohammad Reza Koushki2 and Seyed-Ahmad Shahidi3
1Department of Food Science and Technology, Ayatollah Amoli Branch,
Islamic Azad University, Amol, Iran.
2Department of Food Technology Research, National Nutrition and Food Technology
Research Institute, Faculty of Nutrition Sciences and Food Technology,
Shahid Beheshti University of Medical Sciences, Tehran, Iran.
3Department of Food Science and Technology, College of Agriculture and Food Science,
Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran.
The aim of this study was to determine the microbiological and physicochemical properties of raw milk in Mazandaran province, Iran, during 6 months from winter 2013 to spring 2014. A total of 253 raw milk samples were collected, from dairy farms, milk cans, milk collection centers, and delivery milk tankers. The samples were analyzed for microbial quality, total plate count (TPC), and physicochemical properties including titrable acidity, pH, content of fat and protein, solids nonfat (SNF) level, specific gravity, percentage of water adulteration, and alcohol testing. The mean of TPC was 48×107 CFU/mL. The higher TPC (23×108 ) was found in Chalous city during winter season. TPC less than 106 was used as a basic standard limit by Institute of Standards and Industrial Research of Iran (ISIRI). Significant effect of region was observed on all physicochemical properties except pH (p<0.05). The mean counts of titrable acidity, pH, fat, protein, SNF, specific gravity, and percentage of water adulteration were 15.38, 6.66, 3.42%, 3.04%, 8.33%, 1.029 and 2.11%, respectively, and alcohol stability result of 22.1% of the samples was positive. It can be assumed that raw milk in the study area had poor bacteriological quality according to the Iranian National Standard ( ISIRI ; therefore, it may be hazardous for human consumption. This finding shows the necessity to implement good hygiene practices.
Keywords: Raw milk, Physicochemical properties of milk, Microbiological quality of milk, Iran.