The food vacuum cooling technology is applied in food freezing and preservation, and has the characteristics of fast cooling speed, uniform cooling, clean and sanitary, prolonged shelf life and storage period of products, improved quality, less loss, and convenient operation. At the first Northeast Northeast Refrigeration and Preservation Food Exchange Conference, participating experts and business representatives discussed the application of vacuum cooling technology in food.
Post-harvest pre-cooling of agricultural products used in agricultural product processing is the main application aspect of vacuum cooling technology, and it is also the most mature aspect of application. It can be widely used in the pre-cooling of leafy vegetables and mushrooms, such as spinach, mustard, lettuce, cabbage, sweet corn, lettuce, etc., with good cooling effect. Most European and American countries have already applied the vacuum cooling technology as one of the standardized operations that must be carried out before certain fruits and vegetables enter the market.
Application studies in meat processing showed that the ham of 6.8 to 7.3 kg was reduced from 74°C to 10°C. The ventilation and cooling required 624 minutes and vacuum cooling took only 30 minutes. Vacuum cooling technology can also more effectively control the amount of microbes. In recent years, European and American countries have used vacuum cooling technology in the meat processing industry. For example, Europe has established strict production standards for barbecue products, in which the weight of the barbecued meat pieces does not exceed 2.5 kg and the thickness is less than 100 mm. The center temperature must be reduced from 70° C. to below 10° C. within 2.5 hours. With traditional cooling methods, it is difficult to meet the requirements. Vacuum cooling technology can be used to meet this standard. Domestic Shanghai Fisheries University has studied the vacuum cooling and preservation process of fresh meat. The result is that the meat can be cooled to 1°C within 1 hour and the shelf life of the product can reach 12 days.
Application in processing of soup and seasonings In European and American countries, the use of vacuum cooling in soups and seasonings is common. Vacuum cooling can quickly reduce the temperature of the slurry liquid food material and cool it evenly. It should be noted that when the slurry liquid food is vacuum cooled, the equipment cleaning needs to be solved.
It should be noted that vacuum cooling technology is not a technology that adapts to all foods. Its application requirements are that the specific surface area of ​​the food per unit mass is large, the surface water vapor permeability and the internal effective wet diffusion coefficient are large, and the moisture content is relatively high.