Food Provenance - Food Processing And Production

Question 1

What is primary processing?

Answer 1

This is changing a basic food to preserve it or prepare it for sale or cooking

Question 2

What are some examples of primary food processing?

Answer 2

Milling wheat into flour
Heat treating milk
Peeling, stoning and slicing fruit for canning

Question 3

What is secondary processing?

Answer 3

This is when the primary processed foods are made into other products

Question 4

What are examples of secondary processing?

Answer 4

Making flour into pasta, bread, biscuits

Making milk into cheese, butter, yoghurt

Question 5

How are grains of wheat made into flour?

Answer 5

Through the process of milling

Question 6

How is wheat milled?

Answer 6

First the wheat is cleaned:
Magnets, metal detectors and other machines extract metal objects, stones and other grains such as barley, oats and small seeds from the wheat grain

Then the wheat is conditioned:
Water softens the outer bran layer of the wheat and makes it easier to remove the floury endosperm during milling

Then gristing occurs:
The cleaned and conditioned wheat is blended with other types of wheat to make different kinds of flour. Wheat gluten is sometimes added to increase the protein content of milled flours

Stage 1 of milling:
The grist is passed through a series of fluted break rolls rotating at different speeds. These rolls are set so that they do not crush the wheat but shear it open, separating the white, inner portion from the outer skins.

Stage 2 of milling:
The fragments of wheat grain are separated by a complex arrangement of sieves. White endosperm particles are channeled to a series of sieves of smooth reduction rolls for final milling into white flour

Finally it is separated:
Coarser pieces of bran with endosperm still attached go to a second break roll, and stages 1 and 2 are repeated until the flour bran and wheat germ are completely separated. The result is a number of flour streams containing white flour bran and wheat germ.

Question 7

Describe whole meal flour:

Answer 7

Extraction rate of 100%, meaning nothing has been removed

It is light brown in colour

Question 8

Describe brown flour:

Answer 8

Extraction rate of 85-90% (10-15% of the bran is removed)

It is light brown in colour

Question 9

Describe white flour:

Answer 9

Extraction rate of 75% (the bran, germ, fat and some minerals have been removed)
By law, it must be fortified with iron, calcium, thiamine and niacin
It is white in appearance

Question 10

What are the different types of flour?

Answer 10

Strong flour
Soft flour
Self raising flour
Gluten free flour

Question 11

How is strong flour used?

Answer 11

Since it has a higher gluten content, it used for bread making, and in flaky/choux pastry.
The gluten is able to stretch after it is mixed with water and developed

Question 12

How is soft flour used?

Answer 12

This is used for cake and pastry making and has a lower gluten content

Question 13

How is self raising flour used?

Answer 13

Similar to other flours but it has a chemical raising agent added to it

Question 14

How is gluten free flour made?

Answer 14

Made from flours which do not contain gluten e.g. rice, potato flour
It is made for people with coeliac disease

Question 15

What is homogenisation?

Answer 15

This involves forcing the milk at high pressure through small holes. This breaks up the fat globules in order to spread them evenly throughout the milk

Question 16

What are the different heat treatments available for milk?

Answer 16

Pasteurised milk
Sterilised milk
UHT milk (ultra heat-treated)

Question 17

How is milk pasteurised?

Answer 17

It is heated to a temperature of at least 72oC for a minimum of 15 seconds and a maximum of 25 seconds
The milk is then cooled quickly to below 6oC

Question 18

How is milk sterilised?

Answer 18

It is heated to a temperature of 112-130oC for approximately 10-30 minutes then cooled quickly

Question 19

How is milk ultra heat-treated?

Answer 19

Heated to a temperature of at least 135oC for 1 second.

It is then put into sterile, sealed containers

Question 20

What is the effect of pasteurisation?

Answer 20

Kills harmful bacteria
Has little effect on the nutritional value of milk
Extends the shelf life of the milk

Question 21

What is the effect of sterilisation?

Answer 21

Destroys nearly all the bacteria
Changes the taste and colour
Destroys some vitamins
Unopened bottles can be kept for several months without being in a fridge

Question 22

What is the effect of ultra heat treatment?

Answer 22

Unopened packs have a long shelf life

Little effect on flavour or nutritional value

Question 23

What are the different varieties of milk?

Answer 23

Whole milk - 3.5% fat
Semi-skimmed milk - 1.7% fat
Skimmed milk - 0-0.5% fat
Channel island milk - has a visible cream line, higher in calories and fat
Organic milk - comes from cows grazed in fields where no chemicals are used

Question 24

How is bread made in the industry?

Answer 24

First all the ingredients are delivered to the bakery
Then, all the ingredients are mixed together at high speed for 5 mins. After it is left to prove.
Next, the dough is continuously kneaded for about 2 mins
Then, the tins pass along a conveyer belt where the second proving stage takes place for 50 mins
Then the loaves are baked for 20 mins at 230oC
The baked loaves then come out the oven, they are cooled and then sliced and bagged.

Question 25

How is flour used to make pasta?

Answer 25

The flour is first mixed with liquid, usually water and sometimes egg A lumpy dough is formed It is then put into an extruder where the gluten is developed It is then forced through different shape dies to make different shapes It is then dried and packaged

Question 26

How is butter made?

Answer 26

Butter is made by churning cream to remove the liquid

Question 27

What are the different types of butter available?

Answer 27

Unsalted butter - nothing extra is added Salted butter - salt is added for flavour Clarified butter - butter is melted and the fat that rises to the top is separated and used for cooking Ghee - a form of clarified butter used in Indian cooking Spreadable butter - butter with vegetable oil meaning it can be spread straight from the refrigerator

Question 28

What are the different types of cream?

Answer 28

Half cream - no less than 12% milk fat Single cream - no less than 18% milk fat Double cream - no less than 48% milk fat Whipping cream - no less than 35% milk fat Whipped cream - no less than 35% milk fat (cream has been whipped) Clotted cream - no less than 55% milk fat Sterilised cream - no less than 23% milk fat

Question 29

What are the steps involved in the making of yoghurt?

Answer 29

Milk is pasteurised The milk is homogenised The milk is incubated and the harmless bacteria are added (to change the lactose into lactic acid; the lactic acid causes the milk to coagulate) The yoghurt is let to set until it reaches the correct acidity level Fruit or flavourings are then added

Question 30

What are the steps involved in the making of cheese?

Answer 30

The milk is usually pasteurised and is cooled to 30oC A starter culture of bacteria is added (so that the lactic acid bacteria change the lactose into lactic acid which helps to coagulate the protein in the milk) Rennet is added and the mixture is left to set (the enzyme in rennet will coagulate the milk) The curd is cut so the whey is released For soft cheese - the whey is left to drain away naturally For hard cheese - the curds are heated and piled on top of each other to release more whey The cheese is then milled and for many cheeses, salt is added. The curd is also pressed into moulds Finally the cheese is left to ripen

Question 31

What are the different categories of cheese?

Answer 31

``` Hard - cheddar, parmesan Semi-hard - Cheshire, Wensleydale Soft ripened or bloomy rind - brie, camembert Blue - blue Stilton Washed rind - stinking bishop Fresh - mozzarella, cottage cheese ```

Question 32

What are the advantages of preserving food?

Answer 32

``` Prevents the action of enzymes Lasts longer Can buy/use products when they are not in season Prevents microorganisms from multiplying Increases the shelf life of foods ```

Question 33

What are the disadvantages of preserved foods?

Answer 33

Often contains a lot of fat, sugar and salt Does not contain a lot of fibre Some nutrients are lost Additive may be added to restore the colour The texture of the food may change

Question 34

What is canning?

Answer 34

Canning is a form of sterilisation. Food is packed into cans and then sterilised Cans are then sealed with a double seam to prevent leakage and to prevent contamination

Question 35

What are the high temperature methods of perseveration?

Answer 35

Pasteurisation Sterilisation UHT Canning

Question 36

What are the low temperature methods of perseveration?

Answer 36

Chilling Blast chilling Freezing Accelerated freeze drying

Question 37

What is the cook-chill process?

Answer 37

Food is cooked to a temperature of at least 70oC Portioning is carried out Chilling starts within 30 mins of cooking - rapid chilling where the temperature is reduced to 3oC in 90 mins Once removed from the chiller, food must be heated immediately to an internal temperature of 70oC.

Question 38

What are the advantages of cook-chill foods?

Answer 38

``` No skill required Fresh foods can be kept at maximum quality for a longer time Saves energy in the home Little waste Available in single portions Nutrients are not destroyed ```

Question 39

What are the reasons for an increase in frozen food products?

Answer 39

Gives the consumer more choice Saves time Useful in emergencies Extends shelf life

Question 40

What are the industrial methods of freezing?

Answer 40

Blast freezing Fluidised bed freezing Cryogenic freezing Plate freezing

Question 41

What are the different methods of drying?

Answer 41

``` Sunlight Fluidised bed drying AFD - accelerated freeze-drying Roller drying Spray drying Oven-drying ```

Question 42

What is sunlight drying?

Answer 42

Drying in direct sun light | Moisture evaporates slowly which may allow the food to become contaminated

Question 43

What is fluidised bed drying?

Answer 43

Used to clump dry particles into granules which dissolve more easily in water

Question 44

What is AFD (accelerated freeze drying)?

Answer 44

A combination of freezing and drying It is quick frozen and then placed in a vacuum under reduced pressure The heat vaporises the ice which turns to steam and leaves the food dry Little change to the colour, flavour, texture and nutrition value

Question 45

What is oven drying?

Answer 45

Warm ovens are used | Suitable for herbs, tea and vegetables

Question 46

What is spray drying?

Answer 46

Suitable for foods that may be damaged to excessive heating | Liquids are rapidly dried by a hot gas

Question 47

What is roller drying?

Answer 47

Used for instant breakfast cereal, mashed potato and baby foods The product is dried on a rotating roller that is heated from inside using steam

Question 48

What is smoking?

Answer 48

Involves smoking the food over wood. The chemicals in the wood’s smoke give the food flavour and also help to preserve the food. It is usually dipped in either salt or an acid solution first

Question 49

How is vinegar used to preserve foods?

Answer 49

Vinegar is an acetic acid with a low pH of 3.5 (bacteria cannot survive below 4.5) Used for foods such as pickled onions, cabbage and eggs

Question 50

How is salt used to preserve foods?

Answer 50

Salt is used to coat foods such as ham, bacon and fish | Reduces the moisture content by osmosis

Question 51

How is sugar used to preserve foods?

Answer 51

Sugar in high concentrations (60% or more) prevents bacteria from growing because it makes the water unavailable

Question 52

What is MAP/CAP?

Answer 52

MAP/CAP is referred to as modified/controlled atmosphere packaging. It involves changing the atmosphere around the foods inside the packaging so that growth of microorganisms is slowed down

Question 53

What are different examples of MAP/CAP?

Answer 53

Packaging fresh foods in peak condition; the colour of the food remains the same until the pack is opened Replacing the air by ‘gas-flushing’ a combination of gases around the food; gases used are oxygen, nitrogen and carbon dioxide Sealing the plastic bag or plastic lid to a food tray by means of a double sealing process

Question 54

How is vacuum packing achieved?

Answer 54

It is done by removing air and sealing the package. It prevents bacteria from growing. The food is kept in anaerobic conditions and maintains colour and texture