ABSTRACT
Milk must be of good hygienic quality. This is essential in terms of public health, the quality of the products made from milk, and the suitability of milk for processing. Components that are foreign to milk but enter the milk via the udder or during or after milking, as well as any changes occurring in the milk, are often detrimental to its quality. These matters are the subject of milk hygiene. Microbial, chemical, and physical hygiene may be distinguished. Thus, microorganisms may produce a health hazard (food infection or food poisoning) or spoil the milk, e.g., because they turn it sour during storage. Light-induced off-flavors, fat oxidation, and fat hydrolysis result from chemical or enzymic transformations. Furthermore, compounds that are potentially harmful to the consumer, such as antibiotics, disinfectants, pesticides, and heavy metals, may enter the milk.
