Pasteurization | Pasteurization types | Dairy microbiology (6) | milk | Dairy farming

Summary

This video explains the importance of pasteurization in milk processing, focusing on three main methods: Low Temperature Holding (LTH), High Temperature Short Time (HTST), and Ultra High Temperature (UHT). The speaker highlights the scientific principles behind pasteurization, developed by Louis Pasteur, and elaborates on the techniques used to eliminate harmful pathogens like *Mycobacterium tuberculosis* and *Coxiella burnetii*. Each method is described in detail, with emphasis on the equipment used, the process flow, and the advantages and disadvantages of each technique. The video offers a comprehensive understanding of milk pasteurization and its crucial role in food safety.

Takeaways

• 😀 Pasteurization is a process that applies heat to destroy pathogens in food, especially milk, named after scientist Louis Pasteur.
• 😀 The primary goal of pasteurization is to eliminate harmful bacteria and pathogens like Mycobacterium tuberculosis and Coxiella burnetii.
• 😀 There are three main types of pasteurization methods: Low-Temperature Holding (LTH), High-Temperature Short-Time (HTST), and Ultra-High Temperature (UHT).
• 😀 LTH involves heating milk at 62.8°C for 30 minutes to destroy pathogens, and the milk is cooled rapidly after heating.
• 😀 HTST pasteurization heats milk to 71.7°C for 15 seconds, reducing microbial load by 99%, and is commonly used in the dairy industry.
• 😀 The HTST method is continuous, with pasteurization happening in either an internal or external tubular heater or a plate heat exchanger.
• 😀 In an internal tubular heater, hot water circulates around milk inside inner tubes, while in an external tubular heater, the roles of the hot water and milk are reversed.
• 😀 Plate heat exchangers use thin metal plates to exchange heat between milk and hot water, ensuring efficient pasteurization while saving space.
• 😀 UHT pasteurization heats milk to 130-150°C, killing pathogens, and extending the shelf life of milk significantly, without requiring refrigeration.
• 😀 UHT can be achieved through direct heating (injecting steam into milk) or indirect heating (using surface heat exchangers), with both methods affecting the milk's taste and nutritional value.

Q & A

What is pasteurization and who invented it?

Pasteurization is a heat treatment process designed to destroy pathogens in food, especially milk. It was invented by scientist Louis Pasteur.

Why is pasteurization important for milk?

Pasteurization is important because it kills harmful pathogens, such as bacteria, viruses, and parasites, that could be transmitted through raw milk, ensuring the milk is safe for consumption.

What is the main goal of pasteurization in the dairy industry?

The main goal of pasteurization in the dairy industry is to heat milk or milk products to a specific temperature for a set period to destroy harmful microorganisms without compromising the quality of the milk.

What is Low Temperature Holding (LTH) pasteurization?

Low Temperature Holding (LTH) pasteurization, also known as batch process pasteurization, involves heating milk to a temperature of 62.8°C for 30 minutes to destroy harmful pathogens, including Mycobacterium tuberculosis and Coxiella burnetii.

What are the different types of pasteurization methods discussed?

The three main types of pasteurization methods discussed are Low Temperature Holding (LTH), High Temperature Short Time (HTST), and Ultra High Temperature (UHT) pasteurization.

What is High Temperature Short Time (HTST) pasteurization?

HTST pasteurization involves heating milk to a temperature of 71.7°C for 15 seconds, effectively reducing microbial load by up to 99%. This method is continuous and widely used in the dairy industry.

How does HTST pasteurization work with an internal tubular heater?

In HTST pasteurization using an internal tubular heater, milk flows through inner tubes, while hot water flows through outer tubes in opposite directions. This setup facilitates efficient heat exchange, ensuring the milk reaches the desired temperature.

What are the advantages and disadvantages of HTST pasteurization?

Advantages of HTST include lower initial cost, reduced floor space, and reduced microbial contamination. Disadvantages include challenges in handling small quantities, potential gasket damage, and limited sanitization margins.

What is Ultra High Temperature (UHT) pasteurization?

UHT pasteurization involves heating milk to temperatures between 130°C and 150°C, typically around 137.84°C, to achieve a longer shelf life. This method can use either direct or indirect heating to process the milk.

What are the advantages and disadvantages of UHT pasteurization?

Advantages of UHT pasteurization include prolonged shelf life, the ability to store milk at room temperature, and easier transportation to remote areas. However, it may alter the flavor and nutritive value of the milk due to the high temperatures used.