A/B milk and yoghurt, 428 atto Abbe refractometer. 458 Apo-lactoferrin, 364 of cheese. 4 Apparent viscosity, 454, 455 djunct starters, 41 Arachidonic acid, 142 attenuated lactic acid bacteria, 418 Arteriovenous difference studies. 2( elevated ripening temperature, 41 Arthrobacter spp, 407

Milk has been the subject of scientific study for about 150 years and consequently, is probably the best characterized, in chemical terms, of our major foods. It is probably also the most complicated and serves as the raw material for a very large and diverse family of food products. Dairy science

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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

In modern dairy technology, milk is almost always subjected to a heat treatment; typical examples are: Thermization e.g.65°℃×15s Pasteurization LTLT (low temperature, long time) 63C 30 min HTST(high temperature, short time) 15s Forewarming(for sterilization)

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

The water content of dairy products ranges from around 2.5 to 94%(w/w) (Table 7.1) and is the principal component by weight in most dairy products, including milk, cream, ice-cream, yogurt and most cheeses. The moisture content of foods (or more correctly their water activity, section 7.3), together with temperature and pH, are of great importance to food technology. As described in section 7.8 water plays an extremely important

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 salts of milk are mainly the phosphates, citrates, chlorides, sulphates, carbonates and bicarbonates of sodium, potassium, calcium and mag- nesium. Approximately 20 other elements are found in milk in trace amounts, including copper, iron, silicon, zinc and iodine. Strictly speaking