Bio-purification of plant proteins
The replacement of animal derived proteins with plant proteins is an essential step to ensure a globally sustainable and healthy food supply. However, there are still numerous technological challenges to achieve similar product properties when using plant proteins in alternative products. One of the challenges when replacing animal proteins with plant proteins is the fact that plant protein concentrates/isolates/powders can contain undesired compounds that might:
i) either be perceived as an off-flavor or off-taste,
ii) have antinutritional effects or
iii) interfere with the human endocrine system.
This project aims to develop processes that allow purification of plant proteins by incubation with microbes that degrade these undesired compounds. The processes will be designed in a way that the metabolic activity of the microbe targets the degradation of specific molecules with very limited to no side activities, such as product acidification. Eventually the microorganism will be heat inactivated, leaving the purified product/protein ingredient for further applications. The project is aimed at identifying generic bio-purification strategies and it will explore the possibilities and limitations of such bio-purification processes. The obtained knowledge will be applicable for food producers and ingredient suppliers that are working on the protein transition.
Over the past years it has become clear that a (partial) transition from animal- to plant-based proteins will be of utmost importance to sustain global food supply for the fast-growing world population.
This project fits within MMIP D4 and A4. The objective of the MMIP’s is to change the ratio of animal/vegetable proteins in the human diet towards 40/60 by 2030 through the development and improvement of vegetable and new protein sources and developing sustainable, healthy and consumer-accepted vegetable products. The increased use of plant proteins comes, however, with several challenges, as plant protein flours, concentrates, and isolates often contain undesired molecules, such as off-flavors or off-taste, antinutritional factors, or phytoestrogens.
The aims of this project are to:
- develop new concepts to eliminate undesired compounds from plant proteins and plant protein ingredients in order to improve the usability of plant proteins in existing as well as in new food products.
- deliver bio-purification strategies (combination of selected microbes and incubation conditions), which are applicable for both plant protein ingredient producers (B2B) as well as for producers of consumer goods (B2C).
- broaden the usability of plant proteins in food by improving sensory and health aspects by using bio-purification strategy.
- contribute to the acceleration of the protein transition and to a more sustainable food supply.
Off-flavors are typically caused by volatile compounds, such as certain aldehydes or sulphur containing molecules, whereas off-tastes, such as bitter, astringent or metallic can be caused by proteins, peptides, phenolic compounds, (oxidized) free fatty acids or saponins. Antinutritional factors include phenolic compounds, phytic acid and enzyme inhibitors. Additionally, phytoestrogens occur in numerous legumes and they can either mimic or inhibit the effect of estrogen, however their effect on human health is currently not clear.
Complete elimination of these undesired compounds is generally difficult to achieve with classical processing approaches. To improve the usability of plant proteins in existing as well as in new food products microbial fermentation of plant proteins and plant protein ingredients will be used within the project. The knowledge and experience obtained from fermentative removal of bitter peptides from cheese, diacetyl from beer or aldehydes from soy bean protein in fermented and acidified products will be used. Analogous to the use of adjunct cultures in cheese, non-acidifying cultures will be screened and added to plant protein ingredients.
The results of this project will give insight into the limitations and possibilities of biopurification strategies for plant proteins. The generic parts of successful strategies will be applicable for different protein sources and impurities. This should allow the participating parties to set up their own product specific bio-purification processes. The availability of such a biopurification strategy will broaden the usability of plant proteins in food by improving sensory and health aspects. Together this should contribute to acceleration of the protein transition and ultimately to a more sustainable food supply.
- Selection of undesired components to be removed
- Selection of microbial strains to be used for bio-purification
- Selection of processes for the bio-purification
- Evaluation of opportunities and limitations of the selected approach
- Gaining generic knowledge on practical implementations, including the optimal position of the bio-purification step in the entire process of plant protein ingredient production
- Application of the generated knowledge to in-situ biopurification of plant-based fermented/acidified products
- Delivering of novel (scientific) insight into the metabolism of non-growing cells which is relevant to bio-purification and beyond that for any fermentation-based process in which non-growing cells are present.
- Yearly TKI reports
- Scientific publications are expected on metabolic microbial diversity and removal of antinutritional factors
- Desk study- communication in the form of presentation
Meetings and planning:
- Kick off meeting - Wednesday, 16 September 2020
- Expert meetings – 4 times per year
- Steering committee meetings – 2 times per year