Food Provenance: Food Processing and Production Flashcards
What is primary processing?
changing a basic food to preserve or prepare it for sale or cooking
What is secondary processing?
using a primary processed food to make another product
What are some examples of primary processing?
- milling wheat into flour
- heat treating milk
- extracting olives from crops
- peeling, stoning, slicing fruit for canning or freezing
What are some examples of secondary processing?
- making flour into pasta, bread, biscuits and other flour-based products
- making milk into cheese, butter or yoghurt
Give the process of roller milling
1) magnets extract metal objects, stones and other grains
2) throughout the cleaning process, air currents life off dust and chaff
3) water softens the outer pericarp layer of the wheat and makes it easier to remove the floury endosperm
4) cleaned and conditioned wheat is blended with other types of wheat in gristing, makes different kinds of flour.
5) wheat gluten sometimes added to increase protein content
STAGE 1: grist is passed through fluted break rolls rotating at different speeds, they do not crush the wheat but shear it open
STAGE 2: fragments of the wheat grain are separated by a complex arrangement of sieves, endosperm particles are channelled to a series of sieves of smooth reduction
8) coarser pieces of bran with endosperm are passed through second rollers, and stage 1 and 2 are repeated until complete separation
What is extraction rate?
how much of the whole grain is used
What are the uses of strong flour?
higher gluten content, needed in bread making, able to stretch
What are the uses of soft flour?
cake and pastry making, lower gluten content
What are the uses of self raising flour?
chemical raising agent
What are the uses gluten-free flour?
for coeliacs
What is coeliacs disease?
a medical condition caused by an allergy to the protein gluten, present in cereal
What is fortification?
when a nutrient is added to a product to improve its nutritional value
What is an emulsion?
a mixture of two liquids
What is homogenisation?
involves forcing the milk at high pressures through small holes, breaking up the fat globules in order to spread them evenly throughout the milk and preventing separation of the cream layer
What is pasteurisation?
a method of heat treating milk to kill harmful bacteria
What is sterilisation?
a method of heat treatment which kills all microorganisms
How do carry out pasteurisation?
Heated to a temperature of at least 72ºC for a min of 15s and max of 25s
Milk quickly cooled to below 6ºC
What is the effect of pasteurisation?
Kills pathogenic bacteria
Little effect on nutritional value
Extends the shelf life of the milk
How do we carry out sterilisation?
Heated to a temperature of 113-130ºC for approximately 10-30 mins
Then cooled quickly
What is the effect of sterilization?
Destroy nearly all bacteria
Change taste and flavour
Destroy some vitamins
Unopened bottles can be kept for many months not in fridge
How do we carry out UHT?
Heated to a temperature of at least 135ºC for 1 second
Put into sterile, sealed containers