Milk and Milk Products Flashcards
Types of Milk
Whole Low fat (semiskimmed) Skimmed Buttermilk Supermilk
Nutritional composition of whole milk
Protein: 3.4% Fat: 4% Carb: 4.8% Vit: A, B, D Min: calcium, phosphorus, potassium, magnesium Water: 87%
Mutritonal composition low fats milk
Protein: 3.4% Fat: 1% Carb: 4.5% Vit: B Min: calcium, phosphorus, potassium, magnesium Water: 89%
Nutritional omposition skimmed milk
Protein: 3.5% Fat: 0.3% Carb: 4.6% Vit: B Min: calcium, phosphorus, potassium, magnesium Water: 91%
Milk processing types
Homogenisation
Pasteurisation
Sterilisation
Ultra heat treatment
What is homogenisation
Milk is heated at 60°c Forced through spinerette Fat globules evenly disperse Improves texture, more creamy Fat doenst rise to top as cream
Effects of pasteurisation, sterilisation and ultra heat treatment, condensing and evaporating
Kills pathogenic bacteria
Extend shelf life
Loss of B and D
Milk becomes sweeter due to heat
What is pasteurisation
Milk is heated to 72°c for 25 seconds and then quickly cooled to 10°c
What is sterlilisation
Milk is homogenised, then sealed into glass bottled and heated to 110°c for 30 minutes,then cooled
What is ultra heat tratement
Milk is heated to 132°c for 1-2 seconds and then cooled quickly to 10°c
What is the process condensed milk
Milk is homogenised, pasteurised and 15% sugar is added
It is evaporated to one third volume
Effects of condensing milk
Sugar content makes it sweeter
Increased calorie content
Process of evaporating milk
Milk is pasteurised then evaporated to half its volume
Then it’s homogenised
Sealed into cans
Sterilised at 115°c for 10minutes
Dried milk process
Milk is homogenised and pasteurised
It’s evaporated to 60% of its volume
Dried to form powder by roller drying on hot rollers or spray drying into a hot air chamber
Effects of drying milk
Destroys pathogenic bacteria
Los of vitamin b and amino acids
Extends she,f life to 2-10 years
Doesn’t preserve flavour
Guidelines for buying milk and dairy products
Hygienic retailers Check use by date Buy in small amounts as it has short shelf life Properly sealed packaging Buy near end of shopping trip
Guidelines for storing milks and dairy products
Fridge
Avoid mixing Milks with different use by date
Keep away from strong smelling foods
Minimise time in storage
How does milk spoil
Naturally present lactic acid bacteria breaks down lactose into lactic acid
Lactic acid causes curdling and unpleasant smell
Because caseinogen seprewtes from liquid
Efffects ofheat ón milk
Protein coagulates (skin on surface)
Bacteria destroyed
Sweeter
B group loss
What department controls milk quality in Ireland
The department of agriculture, food and the marine
How does department ensure milk is hygienic
Dairy farms must be registered with the department
Inspecting herds and farms
Inspecting cattle for disease eg tuberculosis (can transmit to human)
Testing milk for bacterial contamination
Ensuring dairy farms follow strict hygiene rules when transporting, processing and storing
Types of creme
Single Pouring cream Double cream Whipping cream Low fat cream UHT cream (aerosol) Sour cream
What is chantilly cream
Whipped cream that has been sweetened or flavoured
Production of cream
- Warmed to 50°c
- Separated from milk
- Heat treated
- Packaged and labelled
Why is milk heated to 50°c to make cream
Makes it easier to separate
How is milk separated in cream making
Using a centrifugal force
Spins milk until upper layer is cream
Bottom layer is skimmed milk
What are the possible heat treatments used for cream
Pasteurisation
Sterilisation
UHT
Culinary uses of cream
Baking
Soups
Savoury dishes
Garnish
What happens when cream is over whipped
Butter and buttermilk
What happens when cream is over heated
Curdle
Low fat cream alternatives
Quark
Natural yoghurt
Greek yoghurt
Fromage frais
Types of butter
Salted
Unsalted
Low fat
Spreadable
Production of butter
- Pasteurised
- Chilled
- Churned
- Drained
- Salt added
- Weighed packaged and labelled
Why is milk churned to make butter
The fat particles clump together
Liquid underneath is buttermilk
% salt in butter
1.5%
Classification of cheese and examples
Hard eg cheddar and Parmesan
Semi hard eg Edam, halloumi
Soft eg mozzarella, feta, cottage
Processed eg cheestrings, babybel, easy singles
Mould cheese (blue veined) eg Stilton and danish blue
What is added to blue cheese
Cultures of the mould penicillium
Cheese production
- Pasteurised
- Starter culture added
- Rennet added
- Curds and whey
- Cut
- Draining
- Scalding
- Cheddaring
- Curd chips
- Salt added
- Pressed and ripened
- Packaged and labelled
What starter culture is added in cheese pasteurisation and why
Lactic acid is the starter culture
This changes lactose to lactic acid
Lactic acid acts as a preservative but also adds flavour
Why is rennet added in cheese making
It contains the enzyme rennin
Rennin changes the protein caseinogen to casein
This coagulates the milk and makes it set
Why are curds cut again
To release more whey
When the whey is drained what soft cheese is formed
Cottage cheese
What is scalding
Curds heated to 30-40°c for 40-45 minutes
Continuously stirred to give the correct consistency
What is cheddaring
Curds are cut into blocks and placed on top of each other to drain more whey
What percentage of salt in added in cheese making
Why is salt added
2%
Adding flavour
Preservative
How is hard cheese made
Curds pushed into mounds with more pressure
How is cheese removed from mould
Sprayed with hot water to make a protective skin then removed
How long is cheese stored for
3-15 months
Why is cheese stored
To develop flavour
The longer the storage the stronger flavour
What is on dairy packaging
Type Ingredients Storage instructions Allergy advice Nutritional information
Types of yoghurt
Set (fermented in individual pots)
Natural (no added flavours or sugar)
Bio yogurt (probiotics add aid digestion and strengthen immune system)
Production of yogurt
Homogenised Pasteurised Cooled to 37°c Starter culture of lactic acid added Fermented for 6-8 hours (lactose to lactic acid) Cooled to 5°c (too cold for any more fermentation) Addition of other ingredients Packaged and labelled
