Although certain yeasts are possibly more resistant to the harsh conditions of pelleting (heat, moisture & shear) it is believed that most are partially or fully inactivated during this process. Encapsulation in a protective matrix is the common approach to reduce or eliminate such inactivation.
Freeze drying is a process of removing water via sublimation of icy water: this means that one needs to first freeze the sample and then place the sample in the freeze dryer set at a very low pressure and low temperature so to remove the water by subliming (“evaporating”) the ice. This process takes usually 3 days to get a dried powder. Moreover, it is not easy to scale up. Spray drying is a process of drying the sample by spraying it through a nozzle into an air-heated chamber. The dried powder is immediately collected by means of a cyclone. Temperature may range between 85-120 degree Celsius depending on the nature and volume of solvent (water or alcohol) to be removed. It is a very rapid process and easy to scale up.
Release of an active from a protective matrix can be triggered by various mechanisms. One example is pH-triggered release – where the matrix swells/disintegrates in a specific pH-range. If the target pH is known a system can be designed to release the active in the hind gut.
The nano-containers used for encapsulation is a natural aluminosilicate clay mineral, belonging to the subclass of phyllosilicates, known and often used as a mycotoxin-adsorbing or sequestering agent.
We have a patented probiotic encapsulation technology for which we sold a commercial licence for human health. We have done some initial work on a similar technology for animal health, which will be available for licensing to the private sector. However, we prefer to develop such technologies in collaboration with the private sector.