Question

Why does the milk that comes in the packet not spoil?

Answer 1

Hint: Milk is a natural food source for mammals. Animals, like humans, produce milk to feed their child until they are prepared for solid food. As being such, milk provides necessary nutrients to help sustain the functioning of the body, especially calcium and protein. The milk that comes in packets is thoroughly processed before they are sent to the outlet.

Complete answer:
Packet milk does not get spoiled due to the practice of pasteurisation procedure that is generally used by the food industry and is the most specific method of heat processing for milk. Pasteurization enables milk to drink (by eliminating any microbes) and also tends to extend its storage life. The pasteurisation system involves boiling milk to 71.7 ° C and holds 15 seconds (but not more than 25 secs). Due to the nature of the heat treatment, it is frequently pointed to as the 'High-Temperature Short Time' (HTST) method. When the milk is being heated, it cools very rapidly to far less than 3 ° C. The device used to heat and cool the dairy is named a 'heat exchanger.' Whenever the milk has been pasteurised, it is bottled or packaged to be distributed to users. Pasteurization is routinely used throughout the milk as well as other food manufacturing plants to guarantee quality and safety of food.

Additional information: Other thermal and mechanical methodologies have been introduced to pasteurise food as a means of reducing the impact on the nutritional and perceptual properties of food and mitigating the deterioration of heat-labile nutrients. Pasteurisation or high-pressure processing (HPP) and pulsed electric field (PEF) are representations of such non-thermal pasteurisation techniques available commercially.

Note: Milk pasteurisation is the way of heating milk at a specified temperature for a specified time avoiding new-contamination throughout the whole operation. The fixed temperature generally depends on the thermal tolerance of the spoilage microbe that the pasteurisation procedure is aiming to destroy. Hence, milk does not spoil that quickly when bought in packets.