The Vegetarian Resource Group Blog

MSG, Hydrolyzed Proteins, and Autolyzed Yeast Extracts: Classified as Flavor Enhancers, not Natural Flavors

Posted on January 20, 2011 by The VRG Blog Editor

by Jeanne Yacoubou, MS
VRG Research Director

A reader wrote to us in December 2010 asking us whether “natural flavor” on a label could indicate monosodium glutamate (MSG) may be present. MSG gives a meaty flavor to foods and is common in many fast food and packaged food products. It is of concern to some people who believe it causes MSG Syndrome in which, upon consuming it, they say they suffer a variety of symptoms including headaches, dizziness, and burning sensations in several parts of the body.

Recall the definition of “natural flavor” found in Title 21, Section 101, Part 22 of the Code of Federal Regulations:

"The term natural flavor or natural flavoring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional."

According to this definition and other information provided by the Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA), ginger or black pepper, (examples given by FSIS on one of its FAQ pages), are natural flavors that need to be declared on a label only as "natural flavors" because they "…do not make a nutritional contribution, are not derived from an animal species, and there are no health concerns linked to them." (This statement seems to imply that natural flavors derived from animals need to be so declared, but we know that this is not the case.)

According to FSIS, MSG is not a natural flavor. It is classified as a flavor enhancer by Federal regulation. It appears from the literature about it and from conversations with employees of companies that manufacture it that MSG, as a flavor enhancer, is used “chiefly for flavor” in an ancillary way, and has no nutritional use in foods.

MSG is chemically related to hydrolyzed protein, another common flavor enhancer designated as such by Federal regulation. MSG is the sodium salt of one amino acid, glutamic acid. (Amino acids are components of protein.) During a chemical breakdown of proteins known as hydrolysis, resulting in hydrolyzed proteins, free (i.e., unbound) amino acids are formed. If free glutamate is formed, (as it will in most cases because glutamic acid is common in almost all foods, especially high-protein foods), it will form MSG when it combines with any salt present in food. According to FSIS, in this case, “the presence of MSG does not need to be disclosed on labeling.”

FSIS states that "…substances such as dried beef stock, autolyzed yeast, and hydrolyzed proteins must be listed on the label by their common or usual names because their purpose is not just for flavor. They are flavor enhancers, emulsifiers, stabilizers, and binders." It is unclear what function other than one related to flavor MSG, as a flavor enhancer, provides in foods. According to the technical definitions of "emulsifiers, stabilizers, and binders," and in the MSG literature, MSG is not properly identified as an "emulsifier, stabilizer, or binder." Neither is MSG classified as a hydrolyzed protein per se despite the fact that hydrolyzed protein is easily transformed in the presence of salt into MSG. FSIS states only that when MSG itself is added directly to a product, must it be identified as "monosodium glutamate" on the label.

Hydrolyzed proteins may be derived from animal or vegetable sources. In neither case may they be labeled simply as "hydrolyzed protein." The source must be disclosed. For example, a label may read "hydrolyzed whey protein" (a dairy derivative) but never just "hydrolyzed protein." Nor can a hydrolyzed protein, of whatever type, be labeled as "natural flavor" (voluntarily further specified by some companies in some cases as animal- or plant-derived).

Readers may also note that autolyzed yeast and autolyzed yeast extracts, also considered flavor enhancers which impart a meaty (or savory) taste to foods just like MSG does, can form MSG if they combine with any salt present in food. In this case, MSG would not be labeled on a package since it has not been directly added to the food.

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3 to “MSG, Hydrolyzed Proteins, and Autolyzed Yeast Extracts: Classified as Flavor Enhancers, not Natural Flavors”

  1. Amy says:

    Excellent post. More people need to be aware of MSG in their food. If you’d like to read more about MSG and all of the other bad nasties in processed food, I wrote a three-part series on it my blog called MSG by Any Other Name. Please check it out here: (Parts II and III are also there as well).

  2. Nicole says:

    What yeasts on the markets are autolyzed? That’s a term I am just now hearing. I heard torola yeast has unbound glutamate but then there’s nutritional yeast and the classic real brewyer’s yeast. I have heard amazing testimonials from people who include yeast in their diets but I don’t want to buy a yeast that has unbound glutamate. How do you know if yeast is autolyzed?

  3. George says:

    This is very important important literature to know in regards to one of the many ways dangerous ” flavor enhancers ” are disguized as other things.

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