Difference Between Tyndallization and Pasteurization

The key difference between tyndallization and pasteurization is that tyndallization is a sterilization method that involves heating the material at 100 °C for 20 minutes on 3 consecutive days intermittent with incubation at 37 °C while pasteurization is a physical method that involves heating of milk either at 63°C for 30 minutes or at 72°C for 15-20 seconds followed by cooling quickly to 13°C.

Sterilization is the destruction of all live forms of microbial life from materials and areas. The purpose of doing this is to prevent transmission of certain microorganisms with objects, hands or skin and prevent spreading of infections. There are physical and chemical sterilization methods. The use of heat is important in many physical sterilization methods such as incineration, tyndallization, autoclaving, hot air oven, pasteurization, direct flaming, etc. This article highlights the difference between tyndallization and pasteurization.

CONTENTS

1. Overview and Key Difference
2. What is Tyndallization  
3. What is Pasteurization
4. Similarities Between Tyndallization and Pasteurization
5. Side by Side Comparison – Tyndallization vs Pasteurization in Tabular Form
6. Summary

What is Tyndallization?

Tyndallization or fractional sterilization is a physical sterilization method. This involves heating the material at 100 °C for 20 minutes on three consecutive days, intermittent with incubation at 37°C. On subsequent exposure to heat, vegetative cells will be destroyed, and any spores that remain without destruction will germinate during the incubation period. Then, during the second heating, the germinated spores will be destroyed again. Repeating the procedure for three days ensures germination of all spores and the destruction of all vegetative cells.

Tyndallization is often used to sterilize culture media and chemical solutions which can’t be heated above 100 °C. However, tyndallization is not a suitable method to kill anaerobic spores and thermophiles.

What is Pasteurization?

Pasteurization is a method of moist heat that eliminates pathogenic microbes in milk and beverages. French scientist Louis Pasteur developed this method. Fresh beverages such as milk, fruit juices, beer vine are easily contaminated during collection and processing. For pasteurization of milk, the temperature used is either 63°C for 30 minutes or 72°C for 15-20 seconds, followed by cooling quickly to 13°C.

The main aim of pasteurization is to prevent the transmission of milk-borne disease agents. Pasteurization also has the advantage of extending milk storage time. However, since pasteurization is not able to kill all spores, it is not a powerful sterilization method.

What are the Similarities Between Tyndallization and Pasteurization?

• Tyndallization and pasteurization are two physical methods involving in eliminating microbial forms from things.
• Both utilize heat to remove microorganisms.

What is the Difference Between Tyndallization and Pasteurization?

Tyndallization is heating of things at 100 0C for three consecutive days with incubation period in between while pasteurization is heating of especially milk either at 63 oC for 30 minutes or 72 oC for 15-20 seconds followed by cooling quickly and sealing. So, this is the key difference between tyndallization and pasteurization. Most importantly, tyndallization destructs all spores and vegetative cells, while pasteurization does not kill spores and all vegetative cells. It kills only pathogenic forms of microorganisms. Therefore, this is also a difference between tyndallization and pasteurization.

The below infographic summarizes the difference between tyndallization and pasteurization.

Summary – Tyndallization vs Pasteurization

Tyndallization is a sterilization method that kills all forms of microbial life, including the spores. On the other hand, pasteurization is a method of eliminating pathogenic microorganisms mainly from milk and some other beverages. But, pasteurization does not kill spores. Hence, it is not a sterilization method. Tyndallization, on the other hand, involves heating the material at 100 °C for 20 minutes on three consecutive days intermittent with incubation at 37 °C. On the other hand, pasteurization involves heating of milk either at 63°C for 30 minutes or at 72°C for 15-20 seconds, followed by cooling quickly to 13°C. Thus, this summarizes the difference between tyndallization and pasteurization.

Reference:

1. “Pasteurization.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 13 Jan. 2016, Available here.
2. “Tyndallization Sterilization: Definition, Process & History.” Study.com. Available here.

Image Courtesy:

1. “Simple Pasteurization” By Emma – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Tyndalls setup for measuring radiant heat absorption by gases annotated” By John Tyndall – The illustration appears in John Tyndall’s 1872 book “Contributions to Molecular Physics in the Domain of Radiant Heat” (downloadable at Archive.org) (Public Domain) via Commons Wikimedia