Milk Pasteurization

Milk Pasteurization

Definition

This can be described as heating milk to a high temperature and then rapidly chilling it with little alteration to its structure, flavor, or nutritional content. -(WHO 1970) (WHO 1970)

It is also possible to define milk pasteurization as a process that involves heating milk to a temperature, allowing it to cool, and then repeating the process as many times as necessary to kill any pathogens while very slightly altering the composition, flavor, and nutritional value of the milk.

A crucial precaution for the public's health is pasteurization. Nearly 90% of the bacteria in milk, including tubercle bacillus, are eliminated by pasteurization, but spores, cream, and protein are not destroyed.

Objectives of Milk Pasteurization

• Primary Objective
  • To completely eradicate the pathogenic microorganisms found in milk. (Make milk free of pathogen-causing microorganisms).
• Secondary Objective
  • To eliminate or destroy as many spoilage enzymes and microorganisms as possible.

Method of Milk Pasteurization

There are various pasteurization techniques, however three are most popular:

• Holder (VAT) Method
  • Milk is quickly cooled to 5°C after being kept at 63-66°C for at least 30 minutes in this process. Small and rural communities can benefit from this approach.
• High Temperature and Short Time Method (HTST method)/Flash Method
  • With this technique, milk is quickly heated to a temperature of almost 72°C, maintained there for at least 15 seconds, and then quickly cooled to 4°C. This approach is currently the most popular one. With this technique, a lot of milk can be pasteurized quickly.
• Ultra High Temperature Method (UHI Method)
  • Milk is typically heated quickly twice. The second stage is typically heated to 125 degrees Celsius under pressure for a brief period of time before being quickly cooled and bottled.

Because heat-resistant bacteria and their spores are not destroyed by pasteurization, the germs may rise and multiply at a later temperature. Pasteurized milk should be quickly chilled to 4 9 C and kept cold until it reaches the consumer in order to avoid this situation. If kept below 18°C, pasteurized milk should be utilized within 8–12 hours to ensure hygiene.

Tests for Pasteurized Milk

• Phosphatase Test
  • This test is frequently used to evaluate how effective pasteurization is. The test is based on the discovery that raw milk contains phosphatase, an enzyme that is destroyed when heated at a degree that nearly resembles the normal time and temperature needed for pasteurization. The enzyme phosphatase is totally eliminated after 30 minutes at 60°C. The test is used to determine whether pasteurization was done properly or whether raw milk was added.
• Standard Plate Count
  • The typical plate count determines the bacteriological quality of pasteurized milk. The majority of Western nations enforce a limit of 30000 bacteria per liter of pasteurized milk. ml of per ml counts
• Coliform Count
  • Since coliform bacteria are often totally destroyed by pasteurization, their presence in pasteurized milk is a sign that either the pasteurization was done incorrectly or there was contamination after the pasteurization process. Most nations require that there be no coliforms in 1 milliliter of milk.

Although drinking cow and buffalo milk is healthy for your health, it can also harm your body and organism. There aren't enough factories to pasteurize milk. Therefore, they must be taught to independently pasteurize in a home environment: Given this:

• Boiling milk takes at least 15 seconds.
• When immersing, exercise caution because milk may become contaminated by water.
• After boiling, the milk container should be quickly cooled by submerging it in ice water.