To achieve that, the researchers are first producing a type of plant-based milk with a composition similar to that of cow’s milk. The starting ingredients are proteins and oils derived from legumes, nuts, rapeseed, or sunflower seeds. The team is also experimenting with adding vari- ous microorganisms, such as lactic acid bacteria and fungi, to the plant-based milk. These organisms break down the carbohydrates and cause the mixture to acidify and curdle. At the same time, they also influence the flavor. “For example, we have found that some microorganisms not only neutralize the ‘beany’ flavor found in legumes, but can even turn it into cheese-like attributes.” Like in traditional cheese making, the fermented plant milk is pressed through a sieve, and the mass is then stored for a time under controlled conditions to allow the flavor and texture to mature. “One key advantage of our method is that we use equipment already present in cheese-mak- ing operations today,” Muranyi notes. There is no need for costly investments, as the production process remains the same. And that has sparked great interest from the industry. A consor- tium of dairies, cheese makers, agri- culture industry players, and produc- ers of microorganisms, enzymes, and other ingredients is supporting and assisting in the research work. The Fraunhofer IVV team’s first focus is on crafting substitutes for Gouda and the Emmentaler variety of Swiss cheese, both of which are highly popular in Germany. In general, it is easier to achieve strong, sharp flavors than the milky, buttery ones found in cheeses like mozzarella or young Gouda. But the scientists have already devised solutions: “Various microor- ganisms convert precursor substances made from plant proteins and oils into substances with active effects on flavor, such as diacetyl, which provides a buttery taste,” Muranyi explains. Shortening the fermentation time could also help create a milder flavor. On the whole, the matu- ration process is much faster with plant-based milk than in cheese made from cow’s milk. “Parmesan is especially easy to imitate,” Muranyi says. Even with over-fermen- tation — such as if the vegan cheese mass is stored at high temperatures for too long or too many microorganisms are used — the texture and flavor are close to those of the popular Italian cheese, which is often grated. The Fraunhofer IVV team is experimenting with various nuts, which are especially suitable for producing cheese-like flavors. Which ones exactly is a secret for now, as competition in the cheese substitute segment is fierce. the flavors naturally, through fermentation.” Dr. Isabel Muranyi, Fraunhofer IVV i l e r u t c i p n a p y b L O P E E D / n o s r e h P c a M m T : i o t o h P 3 | 24 Fraunhofer magazine “We use both the protein and the oil from the nuts in our experiments. The microorganisms break them down into amino acids and fatty acids with an active effect on flavor, which makes them relevant to our cheese taste,” Muranyi explains. The researchers are also experimenting with sunflower seed and rapeseed oil. “With sunflower, though, we’ve found we have to be careful, since it doesn’t take much to turn the cheese green,” Muranyi notes. That is due to the polyphenols that are often present in sunflower proteins, which discolor at certain pH values. “Just like with dairy cheese, we plan to create The second project, Pulse2Cheese, focuses not on the plant-based cheese’s taste, but rather how it melts. Inexpensive cheese substitutes melt well on pizza or in casseroles or baked goods, but they are low in nutrients and typically contain a long list of additives. “With our fermentation processes, we can produce cheese alterna- tives with much greater nutritional value. Our ingredient list is short: proteins and oil from a plant-based raw mate- rial, lactic acid bacteria, and that’s it,” Muranyi says. At the same time, the unsaturated fatty acids derived from plants are healthier than the saturated ones dominant in cheese made from cow’s milk. Healthy ingredients are the third most important factor, after taste and price, that consumers of dairy substitutes — who are generally nutrition-conscious — cite as reasons to buy a certain product. The problem is that the protein-rich plant-based cheese does not melt well when exposed to heat. Instead, it forms a solid lump. The researchers are now looking at ways to add starch to make the protein more flexible, so it bonds to the starch and melts when heated. Legumes are an especially promising starting material. “We’ve already observed under a microscope that the legume proteins form networks like those found in melting cow’s milk cheese,” Muranyi says. Legumes can be grown sustainably, plus they are high in protein, which makes extraction efficient as well. Starch can be produced from the residue. The team of researchers is currently working on the optimal ratio of starch to protein and on perfecting the environmental conditions. “The pH value is one factor, and so is salt content. We have to get those right before the starch and protein interact and the whole system starts to flow,” Muranyi explains. Once they strike the right balance, it won’t be long before a high-quality, sustainable alternative to conventional cheeses is available for pizza and other dishes. 63