In order to make the best possible use of the thaumatin plant in the context of the OCAP idea and to achieve a high value added in the country in question, the plan is not only to intensively cultivate and harvest the fruits, but also to process the plant material and purify the protein in the country of origin. This requires a processing and purification method with scale-up capability, which can also be carried out under the conditions prevailing in the producer country.
Using frozen plant material, a laboratory-scale method was developed in an initial project phase at Fraunhofer IGB, with which thaumatin can be extracted from the seed shells of the fruits and purified.
The method includes the mechanical dissolution of the fiber parts containing thaumatin and, since the protein is very easy to dissolve in water, the aqueous extraction. Modern membrane technologies are used to separate other attendant materials extracted at the same time. In the final process step, the protein is dried to make it suitable for storage and transport. The cleaning steps result in a product that fully conforms to the quality requirements listed in the Foodstuffs Approval Ordinance.