Dairy Processing

Milk processing transforms raw milk into safe, shelf-stable dairy products through a sequence of steps including filtration, separation, standardization, homogenization, and pasteurization. Key processes include heating to kill pathogens (pasteurization) and breaking down fat globules (homogenization). The process ensures quality control, consistency in fat content, and extended shelf life. 

Key Stages of Milk Processing

Receipt and Filtration: Raw milk is received, weighed, and filtered to remove impurities.

Separation and Clarification: Centrifugal forces separate milk into cream and skim milk. A clarifier removes somatic cells and other debris.

Standardization: Fat content is adjusted to specific standards (e.g., whole, skim, or low-fat) by mixing cream and skim milk.

Homogenization: Milk is passed through high-pressure pumps to break down fat globules, preventing cream separation.

Pasteurization: Heat treatment (e.g., HTST: for 15 seconds) destroys harmful bacteria.

Fortification: Vitamins (such as A and D) may be added to enhance nutritional value.

Packaging and Cooling: Milk is cooled to below and packed for distribution. 

Common Heat Treatment Techniques·        Pasteurization: Typically 72–74°C for 15–20 seconds (HTST) to ensure safety while preserving taste.

Ultra-High Temperature (UHT): 135–140°C for 2-4 seconds, allowing milk to be stored at room temperature for months.

Batch Pasteurization (LTLT): 63°C for 30 minutes commonly used for smaller batches. 

Common Dairy Products Processed

Liquid Milk: Pasteurized, homogenized, or UHT milk.

Fermented Products: Yogurt, curd, buttermilk, and lassi.

Fat-Based Products: Cream, butter, and ghee.

Concentrated Products: Evaporated and condensed milk.