Data Logger for Thermal Validation

Thermal Validation of Sterilization Processes and Pasteurization

Do you want to validate critical processes such as sterilization or pasteurization?

With our encapsulated stainless steel data loggers, you can validate sterilization and manufacturing processes such as pasteurization and freeze-drying in the pharmaceutical or food industry with high precision and reliability.

Choose between our two series of validation loggers

Tecnosoft

Highly precise, cost-effective solutions for the validation of sterilization, pasteurization and freeze-drying processes.

DataTrace

High-performance process loggers for sterilization processes and quality assurance

What is meant by pasteurization and sterilization of food?

What distinguishes pasteurization from sterilization and how exactly do these methods work? When is which method used? 

Pasteurization and sterilization are processes in which certain foods are heated to break down their bacterial load. Sterilization almost completely eliminates bacterial colonization, while pasteurization merely reduces it.

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    Historical background: the secret of food preservation

  In the past, food preservation was a real adventure. Various tricks were invented to preserve meat, fruit, vegetables and other foods, but they were only empirical systems based on direct experience and did not always produce the desired results. Why food spoils was a mystery until the 19th century, when the secret was finally revealed.

  French chemist Louis Pasteur made 3 very important discoveries after years of research and experimentation:

  • Microorganisms are the main cause of food spoilage.
  • High temperatures kill microorganisms.
  • Microorganisms always develop from other microorganisms.

  
  These findings have been confirmed in practice:

  • Foods exposed to an intense heat source contain fewer microorganism.
  • The fewer microorganisms present, the longer the food will keep and the safer it will be.
  • Microorganisms can no longer form once they have been completely removed from a food product.

  
  Today's sterilization and pasteurization processes are derived from these discoveries.

  

  
   

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    Explanation: Sterilization processes

  Sterilization process

  This is the most effective process when aiming to completely kill bacteria in food.
  The food is exposed to a temperature of over 100 °C. This temperature, which is higher than the boiling point of water, is lethal to the vast majority of living organisms. It is therefore sufficient to eliminate almost the entire bacterial load of a product.

  After sterilization, food is almost completely free of bacteria, so it can be stored for years at the storage temperature and conditions specified by the manufacturer. The downside is that many of the flavors and nutrients contained in food are temperature sensitive. This means that they cannot tolerate this heat and therefore spoil. As a result, sterilized foods may change their flavor and be less nutritious than fresh produce.
  
  During sterilization, a certain value of F, F0, is defined, which indicates the duration of the sterilization process at 121.11 °C.

  Examples of sterilized food

  On the shelves of supermarkets you can find a whole range of shelf-stable (sterilized) food, including:
  
  

  • Jams
  • Canned food
  • Canned tuna
  • Tomato paste
  • Canned vegetables
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    Explanation: Pasteurization processes

  Pasteurization process

  In this process, food is exposed to a heat that is usually below 100 °C. The food is then dried. At these temperatures, the bacterial flora is partially destroyed but not completely killed. Furthermore, the food does not lose its flavor quality and retains its nutritional properties.

  The pasteurization process is divided in turn into:

  • Low pasteurization: Food is exposed to temperatures of 60-75 °C for a longer period of time (e.g. 30 minutes).
  • High pasteurization: food is exposed to temperatures of 75-100 °C for a shorter time.

   

  Since the bacterial flora is still present, the shelf life of pasteurized products is of course relatively limited. However, the storage time is still longer than that of the fresh product.
  Pasteurization is often used not only to improve preservation, but also to eliminate certain types of bacteria that are hazardous to health, thus making the product safer. This is the case with milk and eggs, which are pasteurized to eliminate heat-sensitive enzymes and pathogens.

  For sugary foods such as honey or beer, pasteurization aims to kill the bacteria responsible for fermentation. Unlike sterilized products, which can be stored at room-like temperatures, many pasteurized products keep best at low temperatures, such as in the refrigerator. In this way, excessive development of the bacterial flora still present is avoided.

  Pasteurization is calculated in PU (pasteurization units). One pasteurization unit is defined as 1 minute during which the product is exposed to a temperature of 60 °C.

  Examples of pasteurized products:

  The following foods are pasteurized:

  • Dairy
  • Cream cheese
  • Cream
  • Beer
  • Basic materials for ice cream
  • Eggs
  • Canned food
  • Honey
  • Fresh pasta

  So pasteurization is also applied to solid foods. In addition, not all of them should be stored in the refrigerator.