Snake venom is a gelatinous liquid, water cannot evaporate out. In order to obtain higher-quality snake venom, we need to dry snake venom as quickly as possible, and without losing its activity in the drying process. There are three kinds of drying methods, namely, vacuum drying at room temperature, freeze vacuum and low-temperature vacuum freeze-drying. The quality of the drying process has great impact on the quality of the venom. The following shall be a brief introduction of the drying process:
1, Drying method
1.1, Vacuum drying at room temperature.
Put the venom and desiccant such as silica gel or calcium chloride into the vacuum dryer, cover them with a layer of gauze, seal the vacuum dryer and exhaust it. In the process, if a large number of bubbles appear, we need to suspend extraction to prevent the bubble spill and continue it after a moment, repeat the process several times until completely drained. Snake venom is seen to be the crystallization of block sizes or particles by vacuum drying.
1.2, Freeze vacuum.
Place the entire vacuum dryer into a large ice bucket, fill small ices around the bucket bottom and the dryer, and exhaust the dryer like vacuum drying at room temperature. Venom can also be pre-placed in the refrigerator until the ice become into blocks, and then vacuum drying.
1.3. Low-temperature vacuum freeze-drying.
Its principle is similar with the vacuum freeze-drying, the difference is nothing absorbent to be used but equipment to dry venom. This method is fast drying speed, high output, easy operation and better ensure the quality of dried venom. But the equipment is expensive,which an ordinary company and a snake farm cannot afford.
2, Commonly used desiccants and their usage.
The commonly used desiccants for snake venom are coloured silica gel, anhydrous calcium chloride, phosphorus pentoxide.
2.1, Coloured silica gel: The color is green when it is dry, and will be lighter after absorbing water and finally becomes pink. After drying out for 1h at the temperature of 100～140 ℃, it can be reused safely and easily, but it is slower absorption.
2.2, Anhydrous calcium chloride: Its water absorption ability is outstanding and it can also be reused. At present, most farms are using this desiccant. Its price is cheaper and it is also easy to use.
2.3, Phosphorus pentoxide: It can be used together with the anhydrous calcium chloride, and it has strong suction. The disadvantage is not easy to re-use, more complex procedures.