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Vacuum Lyophilizer With Stainless Steel
Jan 05, 2019


Introduction of freeze dryer when freeze-dried food


The pre-treated items are quickly frozen, and the faster the freezing, the smaller the crystals in the articles, and the less damage to the structure of the articles. The freezing time is short, and the protein does not undergo a qualitative change under the action of aggregation and concentration.


The food after quick freezing must be vacuum sublimated and dried quickly, and the vacuum is required to quickly reach the sublimation pressure, and the sublimation heat energy is supplied in time to maintain the sublimation temperature, and radiant heating is generally used.


The lyophilized food is porous, and the surface of the tissue is enlarged by 100 to 150 times. Therefore, the chance of contact with oxygen is increased. When returning to normal pressure from low temperature and low pressure, it should be carried out in a nitrogen atmosphere. The pulverization and packaging should be carried out at a relative humidity of 30 to 40% and a temperature of 25 ° C or less.


In order to keep the dry food below 5% water, desiccant should be placed in the package and a small amount of moisture should be adsorbed. Packaging materials should be selected for poor gas permeability, high strength, and good color. Freeze-drying technology can process a variety of vegetables, fruits, fish, beans, condiments, as well as coffee, tea, Chinese medicine and so on.

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