milk nutritive value an excellent source of calcium and phosphorus high in protein low in iron...
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Milk Nutritive Value
An excellent source of calcium and phosphorus
High in protein Low in iron Vitamin A and D added Source of riboflavin
Properties of milk Colloid properties – milk
is made of 2 types of small particles which are mixed together but will separate upon sitting (cream rises to top), homogenization stabilizes this emulsion
Casein – protein in milk Lactose – sugar in milk
Milk Processing Pasteurization – heat milk t 72° C for
15 seconds to kill harmful bacteria Homogenization – forcing milk under
pressure to break up large fat globules so that they stay suspended in the milk, therefore, milk and cream will not separate
Fortification – Vitamin A and D are added back after processing
Forms of Milk Fresh
Homo or whole – 3.5% butterfat 2 % (partly skimmed) – half of the fat is removed
therefore leaving 2% in the milk 1% - 1% fat remains Skim – most of the fat is removed; same
nutritive value as whole with half the calories Vico/Chocolate – chocolate syrup is added to 2%
milk; more costly and more calories
Concentrated Evaporated – either skim or whole with half
water removed; stored in cans; needs no refrigeration; used in remote areas; can disguise the flavour with spices
Condensed – sugar is added to whole milk before it is evaporated; high in calories; used in candy and squares
Powdered – has both fat and water removed; is inexpensive; convenient; once reconstituted, has same nutritive value as whole without the calories
Fermented Buttermilk – in pioneer days, liquid
remaining after churning butter; today, a bacteria is added to 2% which thickens and gives a slight sour flavour
Yogurt – made from 2%; soft solid consistency
Cream products Half and half – blend of milk and cream; 10% fat Coffee cream – 18-20% fat Whipping cream – 36-40% fat Butter – most concentrated source of fat 80% Ice cream/ice milk – air is whipped into cream
and milk to prevent ice crystals from forming; ice milk has same amount of protein and calcium as equal amount of milk but with twice as many calories because of the sugar; ice cream has even more calories
Milk cookery and preparation Curdling – foods with acids, tannins (acid in
potatoes) and salts may cause curdling (clumping together of protein molecules)
Scum formation – protein coagulation; may cause milk to boil over
Ways to prevent curdling: Add acid to milk gradually Heat acid and add to cold milk Heat together for only a short period of time Add acid to a sauce (rue), then add to milk
Tips for Heating and Cooking Milk
Use double boiler Use low heat Use microwave