The Chemical Distinction: Free Glutamate vs. Added MSG
Monosodium glutamate (MSG) is the sodium salt of glutamic acid, an amino acid found in virtually all protein-containing foods. In natural foods, glutamic acid can be bound in proteins or exist as 'free' glutamate, which provides the savory 'umami' flavor. Added MSG, produced through fermentation, is chemically identical to this free glutamate, and the human body processes both forms the same way.
The Umami Connection
Free glutamate is responsible for the 'umami' or savory taste, first identified by Japanese chemist Kikunae Ikeda. This discovery led to the production of MSG as a flavor enhancer. The umami taste in foods like ripe tomatoes or aged cheese is due to the presence of free glutamate.
Natural Foods Rich in Free Glutamate
Many common foods are naturally high in free glutamate, contributing to their flavor profile. These include:
- Aged cheeses such as Parmesan.
- Ripe tomatoes and tomato products like paste.
- Mushrooms, particularly shiitake.
- Fermented items like soy sauce and miso.
- Cured meats and certain seafood, like seaweed.
The Difference Between Naturally Occurring vs. Added Glutamates
The key difference lies in labeling rather than chemistry. Food laws require added MSG to be listed as an ingredient. However, naturally occurring glutamates in ingredients like yeast extract do not need to be labeled as MSG. This means a product can say 'No Added MSG' while still containing natural glutamates. The body does not differentiate between the sources.
Comparison Table: Free Glutamate in Foods
| Food Item | Free Glutamate (mg/100g) | Notes on Glutamate Source |
|---|---|---|
| Parmesan Cheese | ~1200-1600 | Aging process concentrates glutamate. |
| Ripe Tomatoes | ~140-250 | Ripening process increases free glutamate. |
| Soy Sauce | ~1200 | Fermentation of soybeans creates free glutamate. |
| Mushrooms (Shiitake) | ~70-150 | Contains high levels of free glutamate. |
| Dried Kombu Seaweed | ~2240 | The original source from which MSG was first identified. |
| Cured Ham | ~337 | Curing process breaks down proteins into free glutamate. |
| Human Breast Milk | ~22 | Present to aid in infant development. |
A Note on Sensitivities and Health Concerns
MSG is classified as "generally recognized as safe" (GRAS) by the FDA, and scientific reviews have found no convincing evidence of adverse effects from normal consumption. While some people report sensitivity, often termed 'MSG symptom complex,' studies have not conclusively linked these symptoms to MSG. It is the total amount of free glutamate consumed that may potentially cause mild, temporary symptoms in a small number of individuals, not whether it is added or natural.
Conclusion
Natural foods do contain free glutamate, the key component of MSG. This molecule is fundamental to the savory flavors in many foods. The human body processes glutamate the same way regardless of its source. Understanding this helps demystify MSG and allows for informed food choices, recognizing that natural, glutamate-rich ingredients can enhance flavor.
Harnessing Natural Umami at Home
- Use ingredients naturally high in umami like tomato paste, mushrooms, or soy sauce in cooking.
- Incorporate fermented products such as miso.
- Cook with dried kombu seaweed for a strong umami base.
Optional Outbound Link
For further details on glutamate and MSG, refer to the International Food Information Council (IFIC) article: https://ific.org/resources/articles/everything-you-need-to-know-about-glutamate-and-monosodium-glutamate/.
Key Takeaway: What is the main difference between natural and added MSG?
Difference: There is no chemical difference; the primary distinction is the source and how it's listed on labels.
