Yeast extract consists of the contents of yeast cells without cell walls; use them as a food additive or condiment, or as a nutrient in bacterial culture media. They are commonly used to create salty and umami flavors and can be found in a wide variety of packaged foods, including frozen meals, cookies, snack foods, gravies, stocks, and more. They are rich in B vitamins (but not B12), so are particularly important for vegans and vegetarians. Yeast extracts and fermented foods contain glutamic acid (free glutamate), an amino acid that adds umami flavor. Glutamic acid is found in meats, cheeses, fungi (mushrooms), and vegetables (such as broccoli and tomatoes).
Production of yeast extract
Yeast extract is made from natural baker's or brewer's yeast. In early advanced civilizations, fresh yeast was already an important part of dietary culture. It is not only used for baking bread but also for brewing beer and wine.
Yeast extract is obtained from fresh yeast in 5 steps. Enzymes break down proteins present in yeast cells into smaller components and dissolve the surrounding cell wall, allowing the contents to leave the cell. Removal of cell wall residues by dissociation. Yeast extract therefore consists of proteins, amino acids, carbohydrates, vitamins and minerals derived from yeast cells without the surrounding cell wall.
Fermentation
Baker's yeast and Brewer's yeast are living organisms that belong to the fungi family. We use their properties, for example in baking, when we add sugar to the dough and let it rise in a warm place.
The first step in yeast extract production, fermentation, follows the same principle: sugar is added to nourish the yeast. In addition, a temperature of 30 degrees Celsius and sufficient oxygen are supplied to large vessels, so-called fermenters, so that the yeast grows optimally. After this, the yeast is concentrated and washed in a centrifuge to remove residual sugar. The result is a thick, creamy yeast mass.
Damaged
The yeast is then placed in a large jar at a temperature of 45-55 degrees Celsius. Yeast stops growing at about 40 degrees Celsius, and enzymes break down proteins and other large molecules in the yeast into smaller molecules. The cell walls of yeast cells are also partially broken down. This means that smaller molecules can now leave the yeast cells and mix with the water solution in the tank.
A variety of factors can be used to control this process. For example, the time the yeast stays in the tank as well as the temperature play an important role and have a significant impact on the future taste of the corresponding yeast extract. The product produced by this process is a liquid that tastes like broth and, in fact, has an amino acid profile very similar to that of cooked broth.
Final product
To produce the final yeast extract, the liquid must now be centrifuged to remove the yeast cell walls. Valuable proteins, amino acids, vitamins and minerals from the yeast cells are retained in the yeast extract. Simply put, yeast extract contains all the natural components of yeast cells without the surrounding cell wall.
Finally, the yeast extract is concentrated to a paste or liquid in a gentle evaporation process at around 60 degrees Celsius, or by a spray drying process that evaporates all water. The final product is then ready to be shipped to food manufacturers who use the ingredient to flavor their products.
