Yeast extract is the broad term for a variety of processed yeast products used as food flavorings and additives; in a more scientific sense, yeast extract can be used as nutrients for a bacterial growth media. Yeast extracts are made by extracting the cell contents, or removing the cell walls. Yeast extract, when used in foods for flavoring purposes, lends savory flavors and umami taste sensations. Umami? It sounds like a strange word, but it simply refers to a meaty taste given from different amino acids in the product. In this way, it is very similar to MSG, or monosodium glutamate; they both create an umami flavor, and they both have free glutamic acid. Glutamic acid is a non-essential amino acid (meaning it is produced naturally in the body and doesn’t have to be taken in through the diet) important for many biological functions. Learn everything you need to know about the components of yeast extract and about the extract itself right here in this article.
Importance of Glutamic Acid
Glutamic acid is important for the following things occurring in the human body: cellular metabolism; disposal of excess nitrogen; it acts as an excitatory neurotransmitter, one of the most active, in the nervous system; it may play a role in the endocrine system; it is the precursor for a neuron dealing with muscle tone; lastly, it is present in many foods, primarily in the form of monosodium glutamate (MSG) and is responsible for the basic taste that many people experience. The downside to this last thing is that yeast extract is often used interchangeably on an ingredient list with good, however unjust, cause. Many people have serious reactions and are very sensitive to MSG. MSG is commonly used in many products, from cheese to soy sauce, but since manufacturers know the hesitancy of consumers in buying this product because of the possible reactions, they disguise it as yeast extract. Good for them; bad for us. It is important to be aware of this and to read ingredient labels, looking for either one of these, if you do have reactions to MSG.
Different Types of Yeast Extracts and How They are Produced
Yeast itself is a type of fungus (one-celled) and it is capable of converting sugar and starch to carbon dioxide bubbles and alcohol. There are two different types of commercial yeast extracts, the first one being the most popular.
Autolyzed yeas extract uses different concentrations of yeast cells that are free to die and break up; during this process, the yeast’s endogenous enzymes break down the proteins into their simpler components—amino acids and peptides. In the manufacturing industry, sodium chloride is often added to a suspension of yeast, making a hypertonic solution (too much salt on the outside of the cell membranes), causing the water to leave the cells and the cells to eventually shrivel up. This is called autolysis; the yeast basically self-destructs. To complete the breakdown, the dying yeast cells are heated and the walls eventually become separated. When the cell wall is removed, there is a more precise and identifiable flavor and the texture is slightly different.
Hydrolyzed yeast extract involves the exogenous, rather than the endogenous, enzymes; and it works in a way in which hydrolysis breaks down the proteins.
Popular Brands and Uses
Yeast extract is quite popular in New Zealand, Australia, and Great Britain; however, those places are not the limitations of this product. The most popular brands include Vegemite, Marmite, and Promite (all registered ® names). Marmite and Promite are the sweetest but Promite is harder to find. Yeast extract can be spread with butter on bread or it can be mixed with water to make an interesting drink.
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