4. Pasteurisation of Milk
Pasteurisation is a heat treatment in which we heat the food above
65°C and below 100°C depending upon the nature of food, to kill the
pathogenic microorganisms.
Types
1. LTLT pasteurisation
LTLT pasteurisation is a process in which milk was
heated to 63°C in and held at that temperature
for 30 minutes.
2. HTST Pasteurisation
HTST Pasteurisation is a process in which milk is heated to 72°C and held
at that temperature for 15-20 seconds.
5. The Benefits of Pasteurised Milk
Kill the pathogens
Improve taste
No Risk of foodborne illness
The phosphatase enzyme is destroyed by this time/temperature
combination. The phosphatase test is therefore used to check that
milk has been properly pasteurised.
6. Processing of Pasteurised Milk
Reception of Raw
Milk
Balance Tank
Regeneration 1
35-40 °C
Separator
3000-5000 rpm
Homogenization
200-250 Bar
Regeneration 2
55-60 °C
Holding Tubes
15 seconds
Flow Diversion
Valve
Pasteurisation
completed
Heating Section
72 °C
Regeneration 2
55-60 °C
Regeneration 1
35-40 °C
Filling Machine
Cooling Section
4-10 °C
9. Manufacturing of Flavoured Milk
Flavoured milk is a sweetened dairy drink made with milk, sugar, colours
and artificial or natural flavours. Flavoured milk is often
pasteurized using (UHT) treatment, which gives it a longer shelf-life than
plain milk.
Sr No. Ingredient Quantity
1 Milk fat 2 - 3 %
2 MSNF 15 – 20 %
3 Sugar 6 – 7 %
4 Stabilizer 0.05 – 0.1%
5 Cocoa Powder 1 - 2%
6 Chocolate Flavour 0.1%
10. Manufacturing of Flavoured Milk
Reception of
Raw Milk
Mixing of
Ingredients
Pre Heating
45-50 0C
Homogenization
2000 psi
Filling in Bottles
Ua.H.T
140 0C for 2 Sec
Sealing
Cooling
Labelling & Storage
Weighing of
Ingredients
13. Ice cream is a frozen dairy product made by suitable blending and
processing of milk cream and other products, together with sugar &
flavor, stabilizer, color, emulsifier and with the incorporation of air
during the freezing process
Manufacturing of Ice cream
Sr No. Ingredient Quantity
1 Milk fat 10 – 12 %
2 MSNF 10 – 11 %
3 Sugar 13 – 15 %
4 Stabilizer 0.25 – 0.50%
5 Emulsifier 0.25 – 0.50%
14. Manufacturing of Ice cream
Reception of
Raw Material
Mixing of
Ingredients
Pasteurisation
90 0C for 1 minute
Cooling of Mix
< 5 0C
Homogenization
2500 psi
Freezing
-6 0C
Aging of Mix
< 5 0C for 3-4 hrs
Overrun
70 – 100%
Packaging
Hardening
-30 -40 0C
15. Manufacturing of Ice cream
A. Raw Material
B. Mixing Section
C. Pre-Treatment
D. Production Section
7. Aging Tanks
8. Continuous Freezer
9. Bar Freezer
12. Cup cone Filler
16. Extruder Tunnel
21. Blast Freezer
16. The increase in volume caused by whipping air into the mix during
freezing process is known as overrun
Acid flavor
Acid flavor is imparted by dairy ingredients made from sour milk or cream
Staleness
Staleness is due to the use of old ingredients
Oxidized flavor
Copper, iron & ultraviolet rays cause oxidized flavor in ice cream
Salty flavor
Over use of MSNF, dried whey
Sandiness
More MSNF & slow freezing
Overrun
Ice cream Flavour Defects
18. Milk powder is the product obtained by the removal of water from milk by heat to
produce a solid containing less than 5 % moisture.
Classification of Milk Powder
Based on the raw material
1. Whey powder
2. Butter milk powder
Based on fat content
1. Whole milk powder > 26 % fat
2. Skim milk powder < 0.5 % fat
Based on Solubility
1. Instant Milk Powder
2. Non Instant Milk Powder
19. Manufacturing of Milk Powder
Selection of Milk
Pre-treatment
Concentration
40 – 50 %
Homogenization
Spray Drying
180 C
Filling
Fluidized Bed
100 C
Clarification
Standardization
Heat Treatment
90 C 1 minute
Storage
15 C
22. References
Hand Book of Dairy Processing
Publisher: Tetra Pak Processing Systems AB, S-221, Swedan
Editor: Teknotext AB
Illustrations: Origrit AB
Cover: Torkel Döhmers
Printer: LP Grafiska AB
Printed in 1995
