Industry insights from NIZO - From biomass to high-value food product: fermented non-meat proteins

René Floris: Where do single cell, microbial proteins fit into the non-animal protein landscape?​​

Fred van de Velde: While many alternative proteins are being created from ‘traditional’ and familiar plant sources such as nuts, oats, peas, etc., companies continue to develop novel ways to create proteins from various non-animal sources. Technologies such as precision fermentation open up the possibility of ‘animal proteins without an animal’, by using microorganisms to produce specific milk proteins, for example. Others involve turning single cell organisms into a protein-rich biomass through fermentation.

In the latter, a microorganism – such as algae, fungi, bacteria or yeast – is used to ferment a feedstock, to grow a protein-containing biomass. The process requires carbon, nitrogen and energy, but this leaves plenty of variables to work with. For example, a sugar-based feedstock already provides both the carbon and the energy. On the other hand, if you use an alternative feedstock such as natural gas, you must then add energy, such as electricity, and nitrogen, which can be found in the air. 

The feedstock is often made of residue from other industries, such as food processing or alcohol manufacturing. You can even use recycled CO₂​. These possibilities can support very powerful green messaging around turning ‘waste’ into healthy food, for example.

RF: What are the challenges involved in developing a fermented protein-rich biomass and then turning it into a usable food ingredient?​​

FvdV: Often it is smaller, knowledge-based companies taking on these innovative developments, perhaps spin-offs from universities, etc. This means their levels of technology readiness can vary. Some are at a very early point, where they have identified a promising microorganism but haven’t yet grown biomass or produced the specific proteins they are aiming for. Others may already be commercialising their protein-rich biomass as an animal- or aquafeed.

But taking a promising microorganism and basic biomass, and turning them into a usable ingredient for the food industry, is a very complex journey. For example, you need to purify the protein, identify its suitability for different food products, refine the extraction, and possibly even create food prototypes. Each of these steps requires specific skills, equipment and expertise that the company fermenting the protein may not have internally, so outsourcing could offer an efficient way to advance the fermented biomass from extraction to final product.

RF: How do you determine what types of food products a fermented non-animal protein is suitable for?​​

FvdV: Companies producing and selling animal feed biomass often don’t need to purify the protein: they just dry the biomass and add it to the feed. So, the first step is to extract some protein, and do a ‘rough’ purification. This allows you to begin identifying the protein and determining the protein content.

Functionality screening then provides insight into the basic characteristics of the protein that are important for food production: solubility, emulsification, foaming and gelation. This first screening can already provide some ideas for areas of application: a protein that emulsifies well might be suitable as an egg alternative, for a ‘mayonnaise’ product for example, while a protein with good gelation characteristics could work as a meat substitute. On the other hand, this same gelling ability might make the protein unsuitable for a ready-to-drink beverage. ‘Negative’ characteristics that might pop up include colour or an off taste or smell, which could potentially limit the protein’s usability.

This is why it is important to take a holistic look from the very start: simply knowing the protein content, or even quality, is not enough. It requires a broad knowledge of fermentation, proteins, food processing, etc.

RF: Can you increase the usability or value of the protein? ​​

FvdV: The optimal fermentation and extraction methods will depend on the properties of the protein, but also on how you want to use it. Do you need to isolate the protein, or just break the microbial cells open? Do you need to separate broken cells, or can you leave them together? For example, if the protein already has some structure and you want to use it for a meat alternative, perhaps you don’t need to purify it down to a powder – in fact, you might lose functionality that way. It may also be possible to finetune the fermentation to enhance good characteristics and minimise ‘bad’ ones.

Furthermore, non-animal proteins exist in a very competitive market, so you have to find the most cost-effective way to create, extract and purify the protein. This may be quite different from the best method for maximising biomass for animal feed. The more insight you have into the protein and the food products you are aiming at, the more you can target cost efficiency in processing.

RF: What is then needed to bring the protein to the food manufacturers and demonstrate its value?​​

FvdV: Once you have the refined, optimised protein, you want to benchmark it against other proteins in the market, in terms of performance and cost. If your protein can only be used in bread, for example, then you have to position and price it compared to flour. If it could work as a meat substitute, the price points are higher – but so are the performance requirements. This benchmark provides key information to position your protein for the food manufacturers. 

You also need to provide potential customers with the actual protein. This may be in the form of a purified powder or a real food prototype. On a practical level, if your prototype product, such as a non-dairy ice cream, has a good shelf-life, you could have a big batch made up and stored until needed. But if your prototype, perhaps a non-dairy yoghurt, has a shorter shelf-life, you will need to find a pilot plant that can do small batches, quite quickly.

RF: What overall advice would you give to a company that wants to ​turn its microbial protein into a food ingredient?​​

FvdV: This is a highly competitive market, exploding with new, alternative proteins. It is critical to connect functionality with opportunity in terms of real products and markets. There are many aspects to consider: protein content, quality and characteristics, as well as cost, time, etc. Each of the steps along the journey is interconnected with the other. A holistic and multidisciplinary approach will ensure that feedback from each new insight is integrated into the overall development. 

In our next column, we will discuss sustainable fractionation for future-proof food production.​​