Advantages of freeze drying of food freeze dryer:
There are various methods of drying, such as sun drying, boiling drying, drying, spray drying and vacuum drying, etc., but the common drying methods are usually carried out at temperatures above 0℃ or higher. The products obtained from drying generally have the problems of volume reduction and hardening, most of the volatile components will be lost, some heat-sensitive substances are denatured, deactivated, and some substances are even oxidised. Therefore, there is a great difference in the traits of the dried products compared with those before drying.
Freeze-drying method is basically carried out below 0℃, i.e. in the frozen state of the product, and the resolution of drying is generally not more than 60℃. Under vacuum conditions, when the water vapour sublimates out directly, the drug remains in the ice shelf at the time of freezing, forming a sponge-like loose and porous structure, so it is almost unchanged in volume size after drying. Before re-use, as long as the addition of water for injection, and will immediately dissolve.
Food freeze dryer can achieve some of the effects:
1、Many heat-sensitive substances will not be denatured or inactivated.
2、 in the low temperature drying, some volatile components in the material is very small.
3、in the freeze-drying process, the growth of microorganisms and the role of enzymes can not be carried out, so it can maintain the original characteristics.
4、After drying, the material is porous and spongy. When water is added, it rapidly* dissolves and recovers its original characteristics almost immediately.
5、Because of drying in the frozen state, the volume is almost unchanged, keeping the original structure, and no concentration will occur.
6、Because the water in the material exists in the form of ice crystals after pre-freezing, the inorganic salts dissolved in the water are evenly distributed in the material, and when sublimation occurs, the substances dissolved in the water will precipitate, thus avoiding the surface hardening caused by inorganic salts. The inorganic salts carried by water migrate from the inside of the material to the surface.
7、When vacuum drying there is little oxygen, so some oxidising substances can be protected.
8、Drying can remove 95%~99% of water, and the dried products can be kept for a long time without deterioration.
9、Since the material is in frozen state, the temperature is very low, so the temperature requirement of heating source is not high, using room temperature or low temperature heater can meet the requirement. There is no need for heat insulation, and there is not much heat loss, so the use of heat energy is very economical.