Fermentation: An Ancient Process with a Modern Mission in VALORISH

If you have ever baked bread, enjoyed a glass of wine, or eaten yoghurt, you have already experienced fermentation. This ancient process uses microorganisms, such as bacteria, yeast, or fungi, to transform food in ways that make it tastier, healthier, or longer-lasting. Humans have been doing it for thousands of years, long before we understood the science. The word fermentation comes from the Latin “fervere”, meaning “to boil,” a reference to the bubbles seen during early alcoholic beverage production. These bubbles, caused by the activity of yeast on sugars, were the first clue to the invisible work of microorganisms. Over time, fermentation has evolved from a simple preservation method into a process that underpins a wide range of industries.

Today, fermentation is also a powerful industrial tool that can create medicines, sustainable fuels, and innovative ingredients from resources that might otherwise go to waste. And that is exactly what the VALORISH project is doing.

Different Flavours of Fermentation

Fermentation is not a single, one-size-fits-all process. It comes in many varieties, each with its own distinct purpose and end products. In alcoholic fermentation, for example, yeast converts sugars into alcohol and carbon dioxide, giving us everything from wine and beer to certain biofuels. Lactic acid fermentation, on the other hand, is the work of lactic acid bacteria, which preserve and transform foods like yoghurt, kimchi, and fermented cereals. Acetic acid fermentation takes alcohol and, in the presence of oxygen, transforms it into vinegar.

In some cultures, there is also alkali fermentation, where protein-rich ingredients such as fish, seeds, or eggs are fermented to produce distinctive condiments with deep flavours and long shelf lives. And then there is proteolytic fermentation, a process designed to break down proteins into smaller peptides and amino acids, enhancing their nutritional value and functionality. This last type includes traditional solid-state fermentations with fungi, such as the production of tempeh or natto, which hydrolyse the proteins of legumes—typically soybeans—into more digestible forms. Proteolytic fermentation is particularly important for VALORISH, which applies a sustainable twist to the concept.

Microbial Proteolytic Fermentation: The VALORISH Approach

In most industrial proteolytic processes, companies add purified commercial enzymes to break down proteins. VALORISH takes a different path, using microbial proteolytic fermentation, allowing the microorganisms themselves to produce the necessary enzymes during fermentation. This approach can be cost-effective and sustainable: there is no need to purchase and add expensive purified enzymes, and the microbes can be selected or optimised to produce the ideal mix of enzymes for the specific feedstock.

How VALORISH Creates Value from Waste

At its core, VALORISH turns what would otherwise be low-value or discarded biomass, fish by-products, into valuable, functional ingredients for the fish industry. This is achieved through a two-step fermentation strategy that first unlocks the nutritional potential of the biomass and then uses it as a foundation to create entirely new high-value products.

Step 1 – Protein Unlocking

The journey begins with the careful selection of safe, enzyme-producing bacteria from trusted microbial collections. Using computational tools, the project team pinpoints strains best suited to break down the proteins in the chosen biomass.

In the laboratory, scientists at ANFACO test these strains in small-scale fermentation trials. They adjust variables such as the bacterial species, the ratio of raw materials to water, the temperature and pH, or for how long the process runs. The aim is to reach the maximum degree of protein hydrolysis.

Once the desired breakdown is achieved, the resulting mixture, called Fish Protein Hydrolysate (FPH), is processed to concentrate and stabilise it. Large particles are removed through centrifugation and microfiltration, the protein-rich fraction is concentrated using ultrafiltration and nanofiltration, and finally, the product is turned into a fine, shelf-stable powder through spray or freeze drying. This nutrient-dense powder is rich in soluble proteins and suitable for human and animal nutrition, as well as cosmetic applications. In VALORISH, the FPH also serves as feedstock for the subsequent processing step.

Step 2 – New Products

The second stage of VALORISH’s process is where the real value happens. The FPH produced is used to replace expensive commercial peptones — the nutrient base that many industrial microorganisms need to grow. By using FPH, VALORISH not only reduces reliance on costly inputs but also creates a direct link between waste reduction and high-value product generation.

With this protein-rich base, selected microbes are cultivated to produce three high-value products:

• Bacteriocins, which are natural antimicrobials that can help keep food safe by preventing the growth of harmful bacteria.
• Astaxanthin, a powerful antioxidant and red pigment used in dietary supplements, aquaculture feed, and functional foods.
• Vitamin B12, an essential nutrient, is particularly valuable in plant-based diets where it is often lacking.

At SINTEF, these production strains are first tested in microbioreactors under precise control of pH and oxygen levels. The most promising candidates are scaled up to larger bioreactors and eventually to fermenters ranging from 1 to 50 litres, depending on the quantity needed for testing and application. Every parameter is optimised to maximise yield and product quality.

The ambition is straightforward: prove that at least one of these products can be made efficiently enough for real-world food applications. In doing so, VALORISH is not only developing sustainable production methods but also showing that fermentation can transform what we once considered waste into valuable, nutritious, and market-ready solutions.