MILK PROCESSING

STEPS OF PROCESSING

1. Acceptance of milk for processing :

Firstly determine the amount of milk and then determine of quality of the milk
Tests for Raw Milk
- Temperature
- Ph
- Taste and odor
- Density
- Alcohol test
- Protein content
- Fat content
- Total count

2. Filtration section

Removing the organic or inorganic materials that may cause contamination.
This can be achieved by ;
Simple filters
Pipe type filters

3. Cooling section

- Raw milk is transferred to coolling
tanks.
- Temperature of milk is reduced from 20 to 5 C.
- If milk is added to cooled milk, last
temperature must be around 10 C.

Centrifugation

- Materials that are not removed by
filtration is seperated from milk.

- At normal conditions, 1 kg material
removed from 10 000 liter milk.

4. Heating section

- Milk is heated to 35-40 C.
- Cold milk decrease the yield of
cream seperation.
- 35-40 C is the optimum milk
temperature for cream seperation.

Cream seperation

- Its purpose is to seperate milk fat.
- To obtain low fat milk or skim milk.
- To obtain cream
- To standardize milk fat content

Homogenization

– Reduction of fat globules from 3-20µm to <2µm.
– Fat globules are dispersed homogeneously in the milk.
– Prevent the cream formation top of the milk.
– Colour of the milk appears whieter.
– Milk fat is digested easily.
– Milk becomes more delicious.

Deaeration

- Raw milk contain about 6% air.
- Air cause problems during volume measurement of milk,
- Cause heat loss at heating process,
- Reduce the yield of cream seperation,
- Degrease the stability of fermented milk products.

Pasteurization

- Pathogen microorganisms are killed,
- Microorganisms that cause spoilage in milk products are killed,
- Enzymes that are present in milk and produced by microorganisms are inactivated.
- After pasteurization milk is cooled to about 5
C before packaging
- Fillin is done (glass bottle, plastic bag),
- Storage.

Tests for quality of products

- Ash content
- Total solid in milk
- Protein content
- Fat content
- Specific gravity
- Total acidity in milk