Like all other foods of plant or animal origin, milk contains several indigenous enzymes which are constituents of the milk as secreted. The principal constituents of milk (lactose, lipids and proteins) can be modified by exogenous enzymes, added to induce specific changes. Exogenous en- zymes may also be used to analyse for certain constituents in milk. In addition, milk and most dairy products
Milk is a dilute emulsion consisting of an oil/fat dispersed phase and an aqueous colloidal continuous phase. The physical properties of milk are similar to those of water but are modified by the presence of various solutes (proteins, lactose and salts) in the continuous phase and by the degree of dispersion of the emulsified and colloidal components
Cheese is a very varied group of dairy products, produced mainly in Europe, North and South America, Australia and New Zealand and to a lesser extent in North Africa and the Middle East, where it originated during the Agricultural Revolution, 6000-8000 years ago. Cheese production and con- 10A and 10B), is increasing in traditional
Vitamins are organic chemicals required by the body in trace amounts but which cannot be synthesized by the body. The vitamins required for growth and maintenance of health differ between species; compounds regarded as vitamins for one species may be synthesized at adequate rates by other species. For example, only primates and the guinea-pig require ascorbic acid (vitamin C; section 6.4) from their diet; other species possess the enzyme gluconolactone oxidase which is necessary for the synthesis of vitamin C from D-glucose or D-galactose
The milks of all mammals contain lipids but the concentration varies widely between species from c. 2% to greater than 50%(Table 3. 1). The principal function of dietary lipids is to serve as a source of energy for the neonate and the fat content in milk largely reflects the energy requirements of the species, e.g. land animals indigenous to cold environments and marine