Monday, March 18, 2013

Umami, Oh so savory

I admit, that, up to this point, my blog has been somewhat less-than-scientific. Truly, I try to view food and the preparation of food from a holistic perspective, but I find it most fascinating to ask and explain why. Recently I have become fascinated with the five basics tastes: sweet, salty, sour, bitter, and umami, or savory. As it is with most people, the umami taste was the most unfamiliar to me, so I decided to start researching it first. Here is what I have discovered:


Taste has been recognized throughouot literature as primarily a chemical interaction. Kikunae Ikeda, who introduced the world to the concept of umami, observed that, "there must be a close relationship between the chemical structure of a substance and its smell and taste." Four of the five tastes mentioned above have been recognized for quite some time. Ikeda conjectured that a fifth taste existed that was "brothy, meaty, or savory," and could not really be described as a combination of the other basic flavors.

Here is where food science departs slightly from the traditional notion of science: Taste is highly subjective. I have a theory that this is related to the fact that every one has different amounts of the basic chemical receptors we all have in common (I will be researching this in the near future and will let you know what I discover). Thus, an individual is likely to perceive the "flavor chords" of a particular food quite differently from anyone else. For example, I suspect that is why some people are sensitive to trimethylamine in foods, otherwise known as "fishy" taste. I mention all of this because each of us will have a different appreciation of savoriness. Most of us have tasted salt, sugar, highly acidic fruit (sour), and onions or beets (bitter), so those flavors are easily recognizable. However, savoriness is not so easily distinguishable.

The chemical which has been attributed to umami was first identified by Ikeda in an experiment involving macroscopic marine algae, also known as sea weed. Glutamic acid was discovered to be the savory culprit.

Ionic glutamic acid

Okay, for those who are not brushed up on their chemistry/biology, lets refresh our memories: Glutamic acid is an amino acid, and amino acids are key components in proteins (is it starting to make sense why meat is called "savory"?). When a purified acid is in solution, or liquid form, it breaks apart into pieces called ions. Ions have electric charges on them, and can combine with other oppositely-charged ions. One ion that glutamic acid ions readily bond with is sodium; its chemical formula is NaGlu, but most of us know it as monosodium glutamate, or MSG.

As it turns out, the ionic form of glutamic acid is what gives the savory sensation on the tongue. Salts of glutamic acid, such as MSG and MPG (monopotassium glutamate), are simply a convenient glutamic acid delivery system used to enhance savory flavors. A lot has been said of the dangers of MSG, but research has proven that, in general, MSG is as safe for human consumption as salt or sugar. Interesting fact: the lethal dosage of MSG is five times higher than that for salt. If you have concerns about MSG, check out the Wikipedia site. It has some great references and presents some compelling data.

I hope this has been as enlightening for you as it was for me. If I have presented anything you believe to be inaccurate, I would love to hear your comments!

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