Comments about “Deactivated Yeast”

You should never eat raw active yeast, since it will continue to grow in your intestine and rob your body of valuable nutrients. However, once deactivated through pasteurization, yeast is a good source of nutrients. Deactivated yeast is stripped of all its fermenting power. Brewer’s yeast and nutritional yeast, for example, are sold as nutritional supplements, and Australians are fond of yeast extracts—like Vegemite, Marmite, and Promite—which they spread like peanut butter on bread. Autolyzed yeast extract would also fall into this category, although it is taken a step further by the actual breaking down of the cells.

http://www.foodsubs.com/LeavenYeast.html
http://www.cofalec.com/fabr2e.htm

Comments about “Autolyzed Yeast Extract”

Autolyzed yeast and autolyzed yeast extract are products made from yeast cells which are allowed to die and break up, a process called autolysis. The remains of the cells contain small amounts of protein, fats, vitamins and minerals, but most importantly for the prepared food industry, autolyzed yeast and its extract (a more highly concentrated form of the yeast) contain monosodium glutamate, also known as MSG.

Glutamate is an amino acid which is a normal component of the proteins in all animals and plants. Usually in yeast (and in other animals and plants) glutamate is found inside cells, and much of it tightly bound to the proteins of which it is a part. When the yeast proteins are broken down by autolysis to form autolyzed yeast, these release “free” glutamate, so that the autolyzed yeast products have high concentrations of “free” glutamate.

“Free” glutamate is a flavor enhancer. It is added to manufactured foods in the form of autolyzed yeast to increase the tastiness of foods. By itself this glutamate has relatively little taste. However when added to foods it enhances flavors, and particularly the savory flavors found in food items such as prepared meats and potato chips (to name just a couple of the hundreds of foods containing glutamate as an additive). This is why manufacturers like to add autolyzed yeast or yeast extract, or other sources of free glutamate, to their products.

Source: Cornell University, Division of Nutritional Science
http://www.nutrition.cornell.edu/nutriquest/yeast.html