By Kevin Ward
Probiotic bacteria have long been used in probiotic yogurt drinks or provided in tablet form. People have often taken these ‘friendly’ bacteria to help boost their own systems internal flora and fauna; friendly bacteria can help protect our immune system and aid digestion. Bacteria have been known to survive a variety of conditions; however storage in yogurt drinks or tablet form is often not enough.
The bacteria need to survive in large enough numbers to give the end customer a product that has enough active bacteria that they are able to do good. One way in which manufacturers approach this is to supply a much higher load of bacteria at source when the product is made, knowing that a large number of the bacteria will die during storage. However the survival of bacterial at the point of consumption is often not known and there may be little left to give any health benefits.
Biopharma Technology, a UK based freeze drying consultancy company, has been involved in a Technology Strategy Board (TSB) funded project to develop a product that will ensure survival of sufficient friendly bacteria to the gut. This project was conducted in partnership with Microbial Developments and the University of Cambridge. In the first stage we developed a freeze dried product that demonstrated long term storage stability; this project also developed a process incorporating protective agents; to ensure the bacteria was protected during the rehydration stage. Protection during digestion and re-hydration of dried bacteria is an important stage, as the harsh conditions in the gut can kill bacteria.
In the next stage we needed to develop a process to allow the material to be kept dry, survive digestion, re-hydration and survive wet environments prior to consumption. This involved the development of an encapsulation technology to enable material to be dried with protective agents as well as incorporate a protective coating to resist moisture ingress and acidic environments.
The material produced combined the liquid bacterial product, a material to provide structural support, bile adsorbing resin and enteric coating. The key was to try and dry this within one step and form a microcapsule, where the enteric coating is forced to the outside. Spray drying was investigated and after extensive research at Biopharma; it was found that this could provide a dried microcapsule within a single drying process step. This offers a significant advantage in terms of processing costs, simplification of manufacture, as well as economic advantages.
The progress made during this research project could enable supply of controlled doses of friendly bacteria, therefore giving the customer a product where there is a known amount of live bacteria at the point of consumption. In addition to this the technology will extend the range of products in which this technology could be used, whether this is in snack bars, drinks, other food products or nutraceuticals.