Yeast extract has replaced monosodium glutamate, or MSG, as a taste-booster in most processed foods because it appears to be a natural ingredient on food labels. However, yeast extract contains the same concentrated free glutamic acid as MSG. The increasing use of yeast extracts in foods ranging from soups and sauces to meats and canned fish is due to its distinctive taste, resulting from the peptides and amino acids formed by autolysis of yeast protein.
Canned and Frozen Soups
Yeast extract is a clear and water-soluble product formed after the enzymes in the yeast cells autolyze, or dissolve the proteins in the yeast. There are light versions of yeast extracts used in light-colored foods such as bouillon and chicken broth and darker versions for heavier soups. Canned and frozen soups contain yeast extracts to enhance their taste and highlight the flavor of meaty or cheesy ingredients. It is a practice widespread throughout the food industry, and yeast extracts can also be found on the ingredient labels of processed soups proclaimed natural and without MSG, including those sold in nature food stores.
Research by Vanderbilt University has found that although the Food and Drug Administration does not prohibit the use of yeast extract, even when the name is used to disguise the presence of MSG, the quantity of free glutamate it contains poses problems for MSG-sensitive individuals who experience its effects as toxic.
Because yeast extracts contain nitrogen and growth-stimulating compounds, they are used to cultivate microorganisms in foods, in particular dairy cultures. Cheese, including cottage cheese and yogurt, contains yeast extract. The European Association for Specialty Yeast Products reports that yeast extract is widely used both in Europe and the United States to highlight the cheesy notes of dairy products, and although it is an additive, the FDA considers it a natural flavor.
Yeast extract is compatible with all cereal-based products and bakery goods, and it is used widely in these foods. Because it is stable during the processing of foods, it can be frozen, used in a microwave or baked. In its powder form, it is used in the dough of cakes, doughnuts, muffins, rolls and croissants or dusted on the surface, to make the taste of the goods stronger and more appealing and the flavors more well-rounded.
Meats and Canned Fish
Processed meat and fish preparations contain yeast extract. Preformed frozen hamburgers, brand-name turkeys and chickens, lunch meats and even veggie burgers list yeast extract on their labels. Bacon, ham, canned tuna, canned salmon and other canned fish are processed containing the extract. Usually only meat, chicken, turkey, steaks and roasts that are fresh and cut in the store and sold without packaging are free of the extract.
Sauces and Savory Mixes
Sauces, gravies, salad dressings, spice and savory mixes are prime examples of foods containing yeast extract. In fact, yeast extract is sold pure under a variety of brand names to be used at home to flavor soups, stews and casseroles. If you are sensitive to food additives like MSG, read the labels of the foods you buy and avoid those that contain yeast extract. Fresh fruits and vegetables, especially when washed, are always free of the extract.
Most snack foods, including crackers and pretzels, depend on yeast extract for their enticing flavors.