Freeze-drying Protectant For Lyophilizers In Different Fields Application

In the lyophilizer, the function of the lyoprotectant is simply to enable certain formulations to be successfully subjected to vacuum freeze-drying, to improve the solubility and stability of the lyophilized product, to make the lyophilized product aesthetically pleasing, and the like. It is necessary to add some additional substances to the liquid preparation, which are protective agents which must be chemically inert to the lyophilized product.

The following summarizes the application of the lyophilized protective agent in different fields:

1. Microorganisms such as bacteria and viruses need to grow and multiply in specific culture media, but these culture media are often difficult to separate from microorganisms, and they can be successfully lyophilized in these culture media. For example, broth, skim milk and protein.

2. Some lyophilized preparations have a very low concentration and very little dry matter. The dried parts during lyophilization are carried away by the sublimation gas stream. In order to increase the concentration and increase the content of dry matter, the lyophilized product can form a better agglomerate, so it is necessary to add a filling material so that the concentration of the solid matter is between 4% and 25%. These fillers or excipients are sucrose, lactose, inositol, skim milk, hydrolyzed protein, dextran, sorbitol, polyvinylpyrrolidone (PVP) and the like.

3. Some bioactive substances are particularly vulnerable and may be damaged by physical or chemical reasons during freezing and drying. Therefore, some protective agents need to be added to reduce damage during freezing and drying. For example, dimethyl sulfoxide, glycerin, dextran, sugars, and PVP.

4. Adding certain substances can increase the disintegration temperature of the product and make the product easy to freeze. They are mannitol, glycine, dextran, xylitol, and PVP.

5. In order to change the pH of the lyophilized preparation, thereby increasing the eutectic point to facilitate lyophilization. These are sodium hydrogencarbonate, sodium hydroxide and the like.

6, in order to improve the stability of product storage, increase storage temperature, extend storage time. they

It is some antioxidants such as vitamin C, vitamin E, amino acids, sodium thiosulfate, thiourea, lecithin and hydrolyzed protein.

7. Adding certain substances can eliminate free radicals and increase the stability of freeze-dried products. They are amino acids, vitamin K, vitamin C, thiourea, sulfite compounds, sodium aspartate, and the like.

Are there any chemicals involved in the freeze drying process of food?

The general answer is that if it looks like food when it’s dry, then probably not much. It might make sense to spray some antioxidant (like ascorbic acid) onto the outside to protect it, but the product is likely pretty much pristine.