Since ancient times, yeast has proved beneficial in numerous domains, including human nutrition. “It is a natural food ingredient capable of giving flavor to dishes,” explains the R&D manager. “It presents both a biochemical complexity, a reflection of all organic molecules, and taste complexity”. Fresh yeast presents a “fermented taste, reminiscent of meat”. Dried yeast is sweeter and soft in the mouth; it evokes “the taste of chestnuts”. When the yeast has gone through lysis, it can emit a multitude of flavors, by releasing different metabolites: sugars, free amino acids or bonded amino acids (peptides). As with animals we consume, the meat from which tastes different according to the nature of their feed (grass, fodder or prepared feed), the substrate of the yeast, whether that is pure glucose syrup, beet molasses or sugar cane, will hugely influence the flavors that the yeast extracts will then emit.
“At Lesaffre, we have a collection of almost 10,000 yeasts in our strain bank,” specifies Rudy Menin. “This genetic diversity, along with the variety of substrates on which we cultivate these yeasts, the fermenting processes used to make them multiply, and to autolyze, as well as the post-treatments used such as filtration, enable us to generate more than 3,000 different types of peptides.” This extraordinary protein diversity enables us to obtain a diversity of tastes, such as white meat, red meat, vegetables and cheese, and also of cooking methods (barbecue, or a grilled taste).
Yeast extracts to heighten food flavors
Used in cooking, yeast extract improves the taste of dishes and heightens flavors in the same way as herbs or spices. It offers “a rounded, rich balance, that is complex to find,” so that consumers in search of authenticity will be satisfied. “Clients are increasingly moving away from foods with standardized tastes,” indicates the expert. “They wish to rediscover the pleasures of yesteryear, which are judged superior from a taste and quality point of view, and are in search of ‘homemade.’”
Although not all the mechanisms of action are known yet, the possibilities offered by yeast extracts in terms of flavors are countless. “When collected, yeast extracts already present really characteristic tastes, which can also lead to a final flavor when our clients incorporate them into the formulation of their products.” A real chemical reaction takes place, which can go from the flavor of beef bourguignon stew to the taste of grilled chicken, via fruity flavors like apple or banana in beers, and via more pronounced and spicy tastes, like the flavors of cloves or pepper in soups and sauces. “We can now intensify the taste of foods and accentuate the umami effect by heightening the perception of taste on receptors,” explains Rudy Menin. “We can also modulate taste by eliminating the aftertaste (the remaining taste that is negatively perceived), such as metallic or bitter notes,” he adds. “And we can reproduce the filmogenic aspect of fat with yeast extracts, in order to recreate richness in foods and to avoid the transience of their taste.”
Combining taste with healthier food
As such, by incorporating specific yeast extracts into the finished product, it is possible to reduce the fat content, without the consumer perceiving a reduction in the product’s taste quality. It is also possible to reduce the salt content in foods by 20% to 40% with other yeast extracts, while increasing the flavor of foods. “We can also maintain a sweet sensation, even though the sugar content is reduced, or mask after-taste notes typically associated with sweeteners made from Stevia,” underlines Rudy Menin. The aim is to create more balanced, healthier food that is just as appetizing and tasty, and which remains a source of pleasure.
Food innovation using yeast extracts
In order to meet the requirements of its clients more effectively, Lesaffre has set up Culinary Centers, in which innovative, experimental cuisine is carried out. These centers are dedicated to formulating new yeast products, optimizing recipes regionally and providing a concrete response to client needs. “Currently, we have strong demand for meaty tastes within vegetarian recipes, flavors that offer consumers psychological satisfaction and that reference our food since the dawn of time,” affirms Rudy Menin. “We are also working on the structuring of yeast proteins, and on their texturing, in order to reach a highly nutritional solution that will be close to plant steak. In addition, we want to be able to garnish the taste of chicken with aromatic notes.”
There are still numerous avenues to explore. The synergy between bacteria and yeasts is one, which should further increase the wealth of flavors created by Lesaffre.
What is taste?
Quite unlike the other senses, taste requires that you introduce an element of the world into yourself. The taste quality of food stems from its solubilization by saliva, and then the lubrication and ‘deposit’ of food molecules on the tongue. Specialized taste receptors situated in taste bud cells then detect the existing five flavors: sweetness, bitterness, acidity, saltiness and umami. “Umami comes from Japanese culture. It is an impression of fullness in the mouth that accentuates all other flavors,” describes Rudy Menin, R&D manager at Lesaffre. “It often plays an essential role in appetite preservation in elderly people.”
To these five flavors, a sixth is added, Kokumi. It gives a sensation of richness, improving the taste of foods with low fat content. “It is that characteristic foods acquire when cooked for a long time at low temperatures,” adds Rudy Menin, who concludes: “Taste is an association of all the flavors with an impression of fullness, good length in the mouth and complexity, which amplifies the perception of food texture.”