Vacuum freeze-drying technology research and development in China is gradually on the right track

In recent years, vacuum freeze-drying technology has developed rapidly in China, but there is still a certain gap compared with foreign countries. This article starts with the development status of the technology at home and abroad and several aspects that should be improved, and analyzes this technology. .
The growth rate of production is increasing at a rate of 30% per year
Vacuum freezing technology is referred to as freeze-drying technology. The AQSIQ Boiler and Pressure Vessel Detection and Research Center is mainly engaged in the optimization research of the vacuum freeze-drying process. The principle of freeze-drying is to use the principle of sublimation in a vacuum state so that the moisture in the pre-frozen materials is not melted by ice directly. Ice sublimation is removed by steam to obtain a dry product. Practice has shown that vacuum freeze-drying dehydration technology is a high-tech processing technology that is suitable for color protection, preservation, shelf life preservation and nutrition maintenance of fruits and vegetables, meat, aquatic products, and pharmaceuticals.
According to statistics, the United States currently consumes 5 million tons of lyophilized food, 1.6 million tons in Japan, and 1.5 million tons in France. The consumption of other countries is also rising year by year. Today, freeze-dried foods are growing at an annual rate of 30% in the international market.
Research on freeze-drying in China started late. In recent years, some scientific research units have conducted technological research on certain products. Northeastern University has successfully studied the ginseng lyophilization process; Sichuan University studied the lyophilization process of yak meat. In addition, Shanghai Huazuo Development Co., Ltd. has applied some famous dishes, such as “Kung Pao Chicken”, with freeze-drying technology, and has applied for a patent in China. Nowadays, as the demand for freeze-dried products from consumers in China increases year by year, freeze-dried equipment also has a great development.
According to experts, since vacuum freeze-drying is carried out at low temperature and high vacuum, the moisture in the material is directly sublimated from the solid state to the gaseous state, so that the cellular activity of the dried material and the color, fragrance and taste of the dried material can be maintained to the maximum. , shape and nutritional ingredients, and rehydration performance. Freeze-dried foods are high-quality green foods that combine convenience, health care, and naturalness, using modern dehydration technology and processes. This avoids the disadvantages of discoloration, malodor, loss of components, and failure to restore due to the traditional dehydration method.
The overall design and control of the domestic situation have improved
The quality of freeze-dried foods depends not only on the process but also on the food freeze-drying equipment. Food lyophilizers mainly consist of frozen warehouses for freezing materials and drying warehouses for sublimation and dehydration, and ancillary equipment such as vacuum, refrigeration and heating. According to experts, the world's most advanced lyophilizers mainly include: RAY type intermittent type and CON-RAD type continuous type lyophilizers from Atlas Denmark, and Japan No. 0 refrigerated air-freezing process from Republic Vacuum Co., Ltd. Deicing regeneration technology and TL liquid food closed system tube lyophilizer.
In addition, the research institute of cryogenic biology and freeze-drying technology, which was established in Bulgaria more than a decade ago and whose main direction is research on aerospace foods, health foods, and nutritious foods, is also extremely strong.
In recent years, domestic food lyophilizers have developed rapidly and there are many manufacturers, and the quality, performance, and specifications and models vary. In the early 1950s, Wuhan, Beijing, and other biological products research institutes imported freeze dryers; in the 1960s, Beijing, Tianjin, Nanjing, Shanghai, Dalian, and other places successively established experimental freeze-dried food manufacturers. And has imitated a number of lyophilizers. Its characteristics are monolithic, shelf temperature is not uniform, manual operation, can automatically record; in the 1970s in Hubei Hubei designed a freeze dryer, using a single-stage two-stage compressor, can be covered in the bottle stopper; Shanghai A medium-sized freeze-drying plant with an annual output of 300 tons was established.