
History of freezing technology
Historically, the size of the frozen food market has grown significantly in recent years and has doubled in the last 20 years.
The most contributor to this is the advancement of freezing technology, and the latest freezing technology is called ” quick freezing ” .
Especially in Japan, the history of freezing technology is the oldest and most developed in the world, and quick freezing is indispensable as the freezing technology that supports food these days.
Freezing means keeping the temperature below -18 degrees Celsius, but as the name suggests, quick freezing means quick freezing, and “ice crystals break the cell membrane” that makes frozen foods unpleasant. In order to prevent this, it quickly passes through -1 to -5 degrees, which is called the maximum ice crystal formation temperature zone .
In normal freezing (slow freezing), the ice crystals slowly pass through this temperature range, causing the ice crystals to grow and break the cell membrane.

Why do you need freezing?
The main benefit of using freezing is that freezing prevents food spoilage.
In Daijirin, freezing is defined as “freezing to prevent spoilage of food and the like.”
So why does freezing prevent food spoilage and allow it to be stored for long periods of time?

Suppress the growth of microorganisms
It is the action of microorganisms (bacteria) that causes food spoilage.
Bacteria in food are actively activated and proliferated to decompose and ferment the ingredients of food.
Freezing prevents food spoilage by suppressing the activity and growth of this bacterium.
Many of the bacteria that cause food poisoning are difficult to grow below 10 ° C, and become almost inactive at 0 ° C.
Bacteria that are resistant to low temperatures also hardly act at temperatures below -10 ° C.
On the contrary, the temperature range around 10 ° C to 60 ° C is the temperature range where bacteria are actively active.
(Note: The temperature range in which the activity is active differs depending on the type of bacteria.)
In addition, freezing the water in the freezing reduces the water available to the bacteria, thus reducing its activity .
This is the same principle as drying food to suppress bacterial activity and prevent spoilage.

Prevents food deterioration
Freezing also prevents food spoilage as well as food deterioration.
Causes of food deterioration include “oxidation of food,” “drying of food,” and “action of enzymes in food.”
All of them change the quality of food and deprive the food of its taste, freshness and texture.
The lower the temperature, the slower the progress of “oxidation” and “drying” of food, and the action of enzymes can be suppressed, so freezing helps prevent deterioration of food .
