Specific methods for frozen fruits and vegetables

With the continuous development of technology, frozen fruits and vegetables are gradually becoming popular. In addition to being able to preserve freshness, frozen fruits and vegetables also have an advantage that their nutritional content will not be destroyed. What are the specific methods for freezing fruits and vegetables?
1. Quick freezing of fruits and vegetables using air blowing freezing method
Generally, a tunnel type blower freezer is used, and the product is carried through the tunnel with a mesh belt. It generally flows against the cold air, and this freezing method usually uses a cold air temperature of -18 to -34 ℃, with a wind speed of 30-1066 meters per minute.
In addition, there is also the Rotational Freezing method, which can be used for small granular products such as green peas, sweet corn, and various vegetables that are cut into small pieces. The granular products are placed on a perforated mesh belt or a perforated plate, with a thickness of 2.5-12.5 centimeters. When freezing, the cold air is strongly blown up from the bottom direction of the mesh belt at a sufficient speed, blowing the products up but not taking them away. This method increases the contact area between the cold air and the material, and the freezing speed is fast.
2. Low temperature freezing method
This method is a rapid freezing of products under the condition of phase change (liquid to gas) in a refrigerant with a very low boiling point. This is achieved by absorbing a large amount of heat during the boiling phase transition process of the refrigerant, which is absorbed by the product to cool it down. The typical refrigerant is liquid nitrogen with a boiling point of -195.81 ℃, followed by carbon dioxide with a boiling point of -78.5 ℃. This method is faster and more effective than the previous refrigeration methods.