Primary Food Processing 2
Food Preparation & Nutrition: AQA GCSE, topic 6.2.2
Primary Food Processing - Flour
Primary processing involves converting raw foods into foods that can be eaten, cooked, or into ready-to-use ingredients. We produce flour from wheat grains.
Process
- A wheat grain is made up of a bran, germ and endosperm.
- We first harvest wheat grains, then clean them to get rid of any stones or dust.
- To prevent mould growth, we store the grains somewhere dry.
- We place the grains into a hopper to crush the grains. The hopper crushes the grains between its rollers.
Process (continued)
- The type of flour we get depends on how we sieve the grain or what parts we remove:
- Wholemeal flour: nothing is removed - made from 100% grain.
- Wheatmeal flour: some of the germ and bran are taken out. Made from approximately 85% grain.
- White flour: made from endosperm only. Made from approximately 70% grain.
B vitamins
- B vitamins must be added back into white flour as they're lost during production.
Eatwell Guide
- According to the Eatwell Guide, we should consume wholemeal products where possible for the nutritional benefits they provide.
Primary Food Processing - Milk
Primary processing involves converting raw foods into foods that can be eaten, cooked, or into ready-to-use ingredients. Heating milk makes it safe to consume by killing dangerous bacteria.
Pasteurisation
- Involves heating milk for 15 seconds at 72°C before cooling.
- Pasteurisation does not really affect taste and nutritional value.
Ultra Heat Treatment (UHT)
- Involves heating milk for 1-4 seconds at 135°C or above. The milk is placed into a sterile container.
- The milk stays at an ambient temperature for many months.
- UHT milk tastes differently to pasteurised milk and is slightly less nutritious.
Sterilisation
- Involves heating raw milk in a bottle inside a steam chamber for 10-30 minutes at 110°C.
- The process destroys all bacteria and various B and C vitamins.
- Sterilised milk tastes differently to pasteurised milk.
Microfiltration (MF)
- Even after milk has been pasteurised, the bacteria that makes milk go sour live on.
- MF uses a membrane, which the milk is pushed through, to separate the milk and this kind of bacteria.
- MF doesn't really alter the nutritional value or flavour of the milk.
- MF increases milk shelf life.
Test yourself on Primary Food Processing 2
What is flour produced from?
What type of flour is most nutritionally beneficial?
Producing Flour
What is the name of the process that involves heating milk for 15 seconds at 72°C before cooling?
Ultra Heat Treatment