Research from Wageningen University has shown that it is possible to extract protein concentrates from quinoa using a method that is much milder and more sustainable than traditional extraction.
The method better preserves the functional properties of the protein and uses less than half the water, so that less energy is needed to dry the final product, the researchers said. Wageningen University is now looking for industry partners to upscale and conduct pilot tests on the technology.
The traditional method for isolating quinoa proteins consists of grinding, degreasing the quinoa flour using hexane and caustic soda, concentrating the protein with hydrochloric acid, and finally washing, neutralising and freeze-drying. This results in a protein isolate with a protein content of over 90%. The disadvantage of this method though is that it uses a lot of chemicals, as well as large quantities of water, which then has to be removed through drying.
In contrast, the new method, which has already been successfully applied to peas, consists of a dry separation step followed by an aqueous fractionation step. In the dry separation step, the quinoa is carefully ground, following which the lighter high-protein fraction is separated using air. The aqueous fractionation step involves adding table salt and a small quantity of water to the isolate in order to dissolve the protein. Ultrafiltration is then used to remove the water and concentrate the protein.
“With this mild method, we obtain a protein fraction with nearly 60% protein content in the dry substance, and we only need to use 80ml of water for 40g of quinoa flour – approximately half of what is used in the traditional method,” said Geraldine Avila Ruiz from Wageningen University’s food and biobased research team.
“The protein fraction is less pure than a traditional protein concentrate, but it is more natural thanks to the mild processing. This meets the industry’s increasing demand for more natural ingredients,” added Maarten Schutyser, associate professor at the Wageningen Laboratory of Food Process Engineering.
The quinoa proteins obtained using this new technology are suitable for sports food, meat substitutes and other high-protein products. By varying the process conditions the properties can be fine-tuned to various applications, the researchers said.
“For sports food for example, it is important to have a higher protein content, but for meat substitutes you can use a protein fraction that contains a lot of fibre,” they added. With their expertise in the field of separation technology and proteins, they can develop customised quinoa proteins for various applications.
© FoodBev Media Ltd 2024