Why Freeze-Dried Probiotics Require Protective Packaging Freeze-drying, or lyophilization, removes water from a probiotic preparation under controlled conditions. The process can produce a relatively dry and stable material that is easier to store than a highly hydrated microbial preparation. But the resulting product is not completely protected from its environment. Once exposed to atmospheric humidity, freeze-dried probiotics can absorb moisture. Depending on the strain and formulation, moisture uptake can influence the physical properties of the powder and may accelerate loss of microbial viability. Oxygen can also become an important concern. Different probiotic microorganisms have different levels of oxygen tolerance. Therefore, the packaging strategy should be designed according to the characteristics of the individual strain or combination of strains. This is particularly relevant when a formulation contains organisms such as Lactobacillus , Bifidobacterium , Bacillus Coagulans ...