Milk Flashcards
What is milk a good source of?
High biological value protein and calcium.
What percentage of fat is in each millk?
Whole milk - 4%
Semi-skimmed - 2%
Skimmed - 0.1%
What is the percentage of water in milk?
85.2-86.4%
What is the percentage of carbohydrate in milk?
4.8%
What is the percentage of fat in milk?
3.5-5%
What is the percentage of protein in milk?
3.5%
What is the percentage of vitamins in milk?
0.8%
What is the percentage of minerals in milk?
0.7%
What are the 5 steps in order of processing milk?
1) Pasteurisation
2) Homogenising
3) Skimming
4) Sterilising
5) Ultra-heat treating
What happens during pasteurisation?
Milk is heated to 75 degrees C for 25 seconds, then rapidly cooled to 5 degrees C. This gets rid of most pathogenic bacteria but doesn’t affect overall flavour.
What happens during homogenising?
Forcing pasteurised milk through a very fine mesh so that fat globules are broken up and they are evenly distributed through the milk, creating an emulsion.
What happens during skimming?
Skimming the cream (fat) on the milk, producing semi-skimmed, 1% fat and skimmed milk.
What happens during sterilising?
Placing milk in a sealed bottle and heating it to 110-130 degrees C for 30 minutes. This means that it can be unopened and stored for months.
What happens during ultra-heat treating?
Milk is heated to 135 degrees celsius for 1 second, then sealed in storage packs where if not opened can be stored for up to 6 months. This is often called ‘long-life’ milk.
These milks can be further processed into other milk products. Name 3:
-Evaporated milk
-Dried milk
-Condensed milk
What is evaporated milk?
Milk that has had 50% of the water removed, then canned and heated treated. It has a shelf life of 12 months.
What is dried milk?
The water in milk is evaporated by spraying the milk into a chamber of hot circulating air. The water evaporates from the droplets leaving dried milk to fall to the floor of the chamber. Once it is reconstituted with water it becomes like fresh milk again.
What is condensed milk?
Sugar is added to milk, then the milk is evaporated at 55-60 degrees C and immediately cooled to 30 degrees C, then it’s canned and heat treated.
Condensed milk is 3 times more concentrated than fresh milk.
It is commonly used in the confectionary industry for toffee, caramel or fudge.
What 4 factors affect the flavour, fat content and colour of cow milk.
-The breed of cows
-The season when the milk was produced
-The type of grass or ‘meal’ they’re fed
-The age and general health of the cows.
What is the fat content of evaporated milk?
4-10%
What is the fat content of dried milk?
0-3%
What is the fat content of condensed milk?
10+%
Name 4 other products we can produce from milk:
-Yoghurt
-Butter
-Cream
-Cheese
For roughly how long can cows produce milk for?
3 years, before being slaughtered for their meat.