MILK The Complete Food © PDST Home Economics

Sources of Milk  Most milk we drink comes from cows.  Sheep and goats milk are also used  Soya milk is used by vegetarians and those allergic to animal milk

Average Composition of Whole Milk  Protein3.5%  Fat4%  Carbohydrate4.5% A,B,D  Vitamins0.5%  Minerals0.5% Calcium  Water87% What’s missing?????

Nutritive Value  Protein, HBV, growth and repair of cells.  Fat, saturated, for energy, easily digested.  Carbohydrates, sugar (lactose), energy.  Minerals, calcium and phosphorus, bones and teeth.  Vitamins, A (eyes, growth, skin, membranes), B (nerves and energy), D (bones and teeth).  Water, very high amount.

Value of milk in the diet  Important for protein and calcium (for growing and repairing cells and bones)  Lots of different uses.  Inexpensive  Easily digested (elderly, small children, invalids).

Uses of milk  As a drink  On breakfast cereals  Desserts e.g. milk Pudding.  Sauces e.g. cheese sauce  In soup  For baking  Savoury dishes e.g. Lasagne  As a milk product e.g. yoghurt, cheese, butter

Effects of heat on milk  Changes flavour  Kills bacteria  Destroys vitamin C, B  Protein coagulates and makes a skin on the milk.

Storing Milk Milk is easily infected by bacteria so….  Check date stamp  Keep out of sunlight  Cover  Keep away from strong smelling food.  Store in a refrigerator  Use a clean jug …..clean cool covered

Processing Milk  Homogenisation Spreads the fat evenly through the milk.

Heat Treatments (a) Makes milk safe to drink (a) Makes milk safe to drink (b) Helps milk stay fresh for longer (b) Helps milk stay fresh for longerExamples:Pasteurisation Ultra Heat Treated (UHT)

Pasteurisation  Milk is heated to 72ºC for 25 seconds  Then cooled to 10 ºC  Sealed in sterile containers Effects on milk: Flavour change Vit. C destroyed Disease causing bacteria destroyed Some souring bacteria destroyed so milk keeps longer

Ultra Heat Treated  Heated to 132 ºC  Cooled quickly  Sealed in sterile containers Effects on milk: Flavour change All bacteria killed Sealed cartons don’t need refrigeration and keep for months Vitamin C and some B destroyed

Types of milk  Whole milk: nothing added or taken away, just homogenised and pasteurised – children.  Low fat milk: some fat removed – adults  Skimmed milk: almost all fat removed – low calorie and low fat diets.  Fortified milk (super) extra vitamins and minerals added.  Long life milk: ultra heat treated, camping, warm countries

Types of milk  Buttermilk: liquid left over after butter is made, acidic, used in baking.  Dried milk: all moisture removed keeps for long time in sealed container, camping, emergencies.  Evaporated milk: some water removed, sterilised and sealed in a can, keeps over a year, used in cooking - dessert  Condensed milk: some water removed, sugar added, sterilised and sealed in a can, keeps well, used in cooking – dessert  Soya milk: made from soya beans, used by vegans and people allergic to cows milk.

TEST 1. List 2 sources of milk 2. % composition of milk? 3. What nutrients are missing from milk? 4. Why is milk good for teenagers? 5. 4 uses of milk 6. 2 points on storing milk 7. 2 effects of heat on milk 8. What is homogenisation, what effect has it? 9. What is pasteurisation, what effect has it? 10. Name 4 types of milk and give one use for each.

Milk Products  Cream  Butter  Yoghurt  Cheese

Cream  Fat from milk removed by machine in the dairy  Standard Irish cream has 40% fat  Double cream has 48% fat  Soured cream has lactic acid added to give a sharp flavour – used in salad dressing and dips.

Butter  Made from the cream of the milk  10 litres milk = 450g butter (1 block)  Cream is churned until fat globules stick together.  Left over liquid called buttermilk is drained off

Yoghurt  Special harmless bacteria added to warm milk.  Bacteria turn milk sugar to acid which flavours and thickens the milk – natural  Flavoured with sugar, fruit, chocolate, vanilla etc  Made from whole, low fat or skimmed milk.  Can be drinking, stirred, set or frozen.  Some yoghurts help immunity or digestion others help reduce cholesterol

Uses of yoghurt  Healthy snack  Dessert  On breakfast cereal  Accompaniment to curry  Salad dressing  In milk shake