Dairy processing techniques

 Dairy processing techniques are methods used to transform raw milk into various dairy products, such as cheese, yogurt, butter, ice cream, etc. Dairy processing involves several steps, such as pasteurization, homogenization, separation, filtration, drying, etc. Each technique has a specific purpose and effect on the quality, safety and characteristics of the final product. In this blog, we will briefly describe some of the common dairy processing techniques and their applications.

Pasteurization

Pasteurization is the process of heating milk to a high temperature for a short time to kill harmful bacteria and extend the shelf life of milk. Pasteurization can be done by different methods, such as high-temperature short-time (HTST), ultra-high-temperature (UHT), or low-temperature long-time (LTLT). Pasteurization does not affect the nutritional value of milk significantly, but it may alter some of its sensory properties, such as flavor and color.

Homogenization

Homogenization is the process of reducing the size of fat globules in milk to create a uniform and smooth texture. Homogenization prevents the separation of cream from milk and improves the stability and viscosity of milk. Homogenization can be done by mechanical or ultrasonic methods. Homogenization also affects the flavor, color and digestibility of milk.

Centrifugal separation

Centrifugal separation is the process of using centrifugal force to separate different components of milk based on their density. Centrifugal separation can be used to remove impurities, such as dirt and bacteria, from raw milk. It can also be used to separate cream from skim milk or to adjust the fat content of milk for different products. Centrifugal separation can improve the quality and safety of milk.

Ultrafiltration

Ultrafiltration is the process of using a membrane with small pores to filter out large molecules from milk, such as proteins, fats and lactose. Ultrafiltration can be used to concentrate milk solids, such as casein and whey proteins, for cheese making or other applications. It can also be used to remove water from milk to reduce transportation costs or to produce low-lactose products. Ultrafiltration can enhance the functionality and nutritional value of milk proteins.

Reverse osmosis

Reverse osmosis is the process of using a membrane with very small pores to filter out water from milk, leaving behind a concentrated solution of milk solids. Reverse osmosis can be used to further reduce the water content of milk after ultrafiltration or to produce concentrated milk products, such as condensed milk or evaporated milk. Reverse osmosis can increase the shelf life and stability of milk products.

Ultra osmosis

Ultra osmosis is the process of using a membrane with intermediate pores to filter out water and some small molecules from milk, such as lactose and minerals. Ultra osmosis can be used to produce low-lactose or low-mineral products, such as whey protein isolate or demineralized whey powder. Ultra osmosis can modify the composition and functionality of milk components.

Spray drying

Spray drying is the process of converting liquid milk into a fine powder by spraying it into a hot air stream. Spray drying can be used to produce various types of milk powder, such as whole milk powder, skim milk powder or instantized milk powder. Spray drying can preserve the nutritional value and flavor of milk for a long time and make it easy to store and transport.

Permeate

Permeate is the liquid fraction that passes through a membrane during ultrafiltration or reverse osmosis. Permeate contains water and some dissolved solids, such as lactose, minerals and vitamins. Permeate can be used as an ingredient in dairy products, such as yogurt or cheese, or in other food products, such as beverages or baked goods. Permeate can improve the texture, flavor and nutritional value of food products.

These are some of the common dairy processing techniques that are used in the industry today. Each technique has its own advantages and disadvantages depending on the type and quality of raw milk and the desired characteristics of the final product. Dairy processing is a complex and dynamic field that requires constant innovation and adaptation to meet consumer demands and preferences.

Novel dairy processing techniques are methods that aim to improve the quality, safety, functionality and energy efficiency of dairy products. Some examples of novel techniques are:

1.  high pressure processing

High pressure processing (HPP) is a non-thermal method of preservation and sterilization of dairy products, in which a product is subjected to very high pressure, leading to the inactivation of certain microorganisms and enzymes in the food. HPP can improve the shelf life, texture, flavor and nutritional value of dairy products, such as milk, cheese, yogurt and ice cream.

2. pulsed electric field

Pulsed electric field (PEF) is a non-thermal method of preservation and modification of dairy products, in which a product is subjected to short pulses of high voltage electric field, causing electroporation of cell membranes and inactivation of microorganisms. PEF can also affect the structure, functionality and interactions of dairy proteins, such as caseins and whey proteins, leading to changes in gelling, foaming, emulsifying and nutritional properties

References:

1. Dairy production and products: Processing - Food and Agriculture Organization (FAO)
2. Basic Facts About Dairy Processing and Technologies
3. https://www.mdpi.com/2304-8158/11/11/1556
4. https://mdpi-res.com/d_attachment/foods/foods-11-01556/article_deploy/foods-11-01556-v2.pdf?version=1653547064
5. https://europepmc.org/article/MED/35681305