What is the Pasteurization Process?
Pasteurization is named after the French scientist Louis Pasteur, who found that the process of heating wine in the 1880s would inactivate bacteria / pathogens that caused spoilage.
The pasteurization process was primarily associated with milk, but is now used to extend the shelf life of most beverages, including fruit juice and beer and also some foods, such as canned foods and eggs.
“It is intended to sterilize
foods by destroying or inactivating organisms that contribute to spoilage
, including vegetative bacteria
but not bacterial spores.” (Source: Wikipedia
Different Pasteurization Methods:
There are now a few different ways to pasteurize a product, based on variations in time and temperature.
- Low-Temperature-Long-Time-Treatment (HTLT) / Batch / Vat Pasteurization – used for heating a product to whilst stirring.
Eg. the oldest method, this is used often in small scale milk operations
- High-Temperature-Short-Time-Treatment (HTST) / Flash Pasteurization – products are heated to about 72°C for 3 to 15 seconds and then rapidly cooled,
Eg the most common method used today, eg fruit juice packs
- Ultra-High-Temperature (UHT) Pasteurization – heating a product to about 145°C for 1 – 2 seconds
Eg UHT milk and custard
- Steam Pasteurization– food is exposed to temperatures of about 90°C in a chamber of pressurised steam for 6-8 seconds and then cooled
Eg meat carcasses
- Irradiation Pasteurization – a “cold / electronic” technique, food is subjected to ionising radiation from gamma rays or x-rays in order to reduce micro-organisms and sterilise foods
eg meat, herbs and spices
- High Pressure Pasteurization (HPP) – a newer cold pasteurisation technique that processes already sealed foods at extremely high water pressure (up to 87,000 psi)
Eg pre-packaged cold meats
- Microwave Volumetric Heating (MVH) is a new technology that uses microwaves to heat substances in a continuous flow and allows for very controlled, gentler and shorter heating that helps preserve most of the heat-sensitive substances in milk
How to Monitor Beverage Pasteurization:
In order to ensure safe products, quality assurance checks need to be done throughout the pasteurization process.
A Pasteurisation Data Logger
can be used throughout the pasteurisation process to record temperature and / or pressure values, which can then be downloaded onto a computer.
Modern technology has led to the development of miniature electronic data loggers, such as the DST Milli-PU
, which can conveniently fit inside a can or a bottle on the production line.