Raw Milk Microbiological Characteristics
The microbial content of milk is a major feature in determining its quality. It indicates the hygiene level during milking, i.e., cleanliness of the milking utensils, proper storage and transport as well as the wholesomeness of the udder of the individual cow.
Microbial levels of milk immediately after leaving the udder are in the range of 100 – 1000 germs per cubic cm. The environment (air, feed) contributes about 10,000 germs and the post milking installations (insufficiently cleaned milking installations, tanks, pipelines, transport facilities) can contribute ten thousand to millions of germs.
If the milking temperature would be maintained, then there will a doubling the germ count within 20 0- 40 min.
In milk normally find mostly acid-producing streptococci (spherical bacteria, growing in chains) and lactobacilli (rod-shaped lactic acid bacteria). Further will find micrococci, coliform bacteria as well as spore forming bacilli and clostridia (mainly due to contamination from silage). Due to the chilled storage of milk at 2–4 degree C, very often psychotropic forms appear, and they can cause negative changes in milk (sensorial defects, chemical degradation) due to propagation and metabolism. Storage temperature of 8–1 degree C recommended.
Raw Milk Microbiological Characteristics
