This release is available in German.
Probiotic bacteria are rapidly gaining ground as healthy food supplements. However, the production of this "functional food" has its pitfalls: only few probiotic bacterial strains are robust enough to survive conventional production processes. Researchers from Technische Universitaet Muenchen have now developed a particularly gentle method that allows the use of thus far unutilized probiotics. The outcome is beneficial for both manufacturers and consumers: it's energy and cost efficient -- and it makes probiotics less perishable.
Probiotics, as functional supplements, are good for both the immune system and for intestinal health. But how do they get into the yoghurt jar? So far, probiotic bacteria are mostly freeze-dried, before they are used in high concentrations in foods. However, the freeze-drying process is problematic for some probiotics it means certain death, and it is also quite energy consuming. The probiotics must first be frozen and in a second step heat is inserted in the sample to transform the ice directly into steam. Thus water is removed from the bacterial culture. The TUM researchers from the Chair of Food Process Engineering and Dairy Technology decided to save themselves this "detour" and tried to find a drying process that is both gentler and more environmentally friendly.
That is how the TUM researchers came across low temperature vacuum drying (LTVD) a process that runs under mild conditions. The product remains in a liquid state, since in a vacuum the evaporation takes place at low temperatures: For instance, water boils at 8C in an atmosphere of 10 mbar air pressure. Compared to freeze-drying, this method requires 40% less energy. Dr. Petra Frst's team at the Chair of Food Process Engineering and Dairy Technology conducted experiments on this process using three probiotic bacte
|Contact: Jana Bodicky|
Technische Universitaet Muenchen