Use fermentation to incorporate flavor, health benefits, and shelf life into dairy and plant-based foods

In a previous article, I briefly touched on the benefits of fermentation. Food safety, Health benefitsand Protein migration.. Its important role in the dairy sector is undeniable, but its importance for developing plant-based products is growing rapidly. However, culture selection, strain mixing, and control of the fermentation process have never been easier. To find a way to do that, talk to Wim Engels, a senior project manager at NIZO and a food fermentation expert with over 30 years of experience in the fields of fermentation, chemistry, biochemistry and cheese aging. I heard.

René Floris: What is fermentation and what benefits does it bring to the food industry?

Wim Engels: In food fermentation, live microorganisms alter the chemical properties of food ingredients or products through enzymatic metabolic processes. For food manufacturers, fermentation can:

  • Extends food shelf life and safety
  • Helps add health benefits such as vitamins, (bioactive) peptides, probiotics to foods and lower sugar, fat and salt levels
  • Provides a very pleasant and deep taste and texture

It also does all this without adding any components or ingredients, supporting the goal of “clean labels”, for example.

RF: How is fermentation “designed” for food?

WE: When developing food, there is rarely a single bacterial strain that produces all the properties it needs. In general, we choose the “starter” culture that is responsible for the main fermentation, then add the “auxiliary” culture for specific flavors, textures, storage properties, etc. Creating this balance is very complicated. Bacteria are organisms that do not always behave as we want or expect. Different strains may be most effective under certain temperature or oxygen conditions, so it is necessary to combine strains that grow and metabolize in the same environment. Finally, strains interact with each other, sometimes in undesirable ways.

High-throughput screening of culture collections can provide insights such as these acidification curves of various bacterial strains in plant protein emulsions. Image Source: NIZO

You need to understand starter bacteria and their metabolism. A method of converting amino acids into compounds that contribute to flavor and texture. This allows you to indicate a combination of cultures, for example if you need a “Gouda flavor profile”.

Still, bacteria can act in unexpected ways. There is no decision tree to specify that “running A, B, C will definitely give result D”.

RF: So how do you test a combination of bacteria and strains?

WE: Initial screening of bacteria is usually done in laboratory medium, but behavior may differ when more complex substrates such as dairy products, plant protein-based emulsions, etc. are applied. A large screening culture collection of properties such as fast acidification using existing ones can provide insight into the appropriate strain.

Microscale testing of the function of microorganisms in “real” food substrates such as cheese is a time- and cost-effective step. You can then scale up to see how the process affects your results. Bacterial behavior and metabolism are highly environmentally sensitive, so even small changes in the process can significantly change the outcome.

RF: How did fermentation help food manufacturers solve real market needs?

WE: Fermentation has been widely used in the dairy industry for decades and the process is very sophisticated and tuned. For example, we at NIZO have developed strains with very specific properties, such as for flavor diacetyl and nisin.

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Plant-based cheese after storage at 6 ° C for 6 weeks. The upper cheese was acidified with lactic acid and showed widespread mold growth, while the lower fermented sample showed nothing. Image Source: NIZO

Storage, reduced bitterness, temperature or pH range tolerance, or performance on the surface of cheese. This gives product developers a huge toolbox to work with.

For example, if you are developing cheese with reduced fat and salt, you may have problems with taste, texture, contamination, and spoilage. To solve them by fermentation, the focus is on choosing a starter culture that creates suitable conditions that allow for a long shelf life (eg, by producing fast acidification or antibacterial compounds such as nisin) and cheese. It’s about adjusting the flavor and texture profile of. With the appropriate auxiliary strain. In this way, it is possible to develop cheese processing techniques that allow the development of full flavors with less salt or fat.

RF: How is this knowledge of dairy fermentation transformed into plant-based alternatives?

WE: For example, mold growth is always a concern in plant-based cheeses, but it can be addressed by rapid acidification. This can be done chemically, for example by adding lactic acid or by fermentation. Through our own research, we have shown that fermentation-acidified plant-based cream cheese is more resistant to mold than lactic acid at the same pH.

These results can be used to optimize your processing strategy. However, bacteria cannot simply “copy” the fermentation process and mixture from the dairy world because they react differently than plant-based substrates, which have different sugar, protein, fat, and water content.

RF: How can we use accelerated evolution to “design” bacteria that provide the required properties?

WE: Bacteria grow so fast that they can be adapted by repeated inoculation of the substrate of interest. It’s not absolutely certain, but you can maximize your potential by starting with the best stocks,

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The production of the desired flavor compounds (acetaldehyde, diacetyl, 3-methylbutanal) and the removal of off-flavour (hexanal) depend on both the strain and the substrate. Image source: NIZO

Know what you expect and what you want, and use genomic sequencing to control and monitor the new metabolic capacity of microorganisms.

For example, when making soy-based yogurt, there are two important hurdles. First, the complex sugars in soybeans are not ideal for fermentation of dairy products with lactic acid bacteria. Second, soy products tend to give consumers “off” flavors that they don’t like.

To address these challenges, use accelerated evolution to adapt dairy yogurt cultures and control them frequently to grow multiple times on soymilk substrates to see if they are evolving in the “right” way. Did. Within six months, we have created a whole new cultural combination that can produce drinkable yogurt with the desired smoothness and taste, with no or reduced “off” flavor.

RF: How does a fermentation knowledge-driven culture design improve the flavor of plant proteins?

WE: The wide range of fermentation possibilities for improving the quality of plant-based proteins is recognized by stakeholders at all levels who are initiating collaborative research to address the challenge. One example is the public-private “biopurification of plant proteins” TKI Agri & Food project chaired by NIZO. The aim is to develop a general fermentation process to improve the flavor and texture of vegetable proteins and isolates.

Next month, we’ll return to protein migration to explore ways to control pathogens in the chain, especially for plant-based products. Use fermentation to incorporate flavor, health benefits, and shelf life into dairy and plant-based foods

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