Molecule of the Day

99 years ago, a Japanese researcher was looking into some puzzling stuff. A broth of kelp, when boiled down, yielded some brown crystals that tasted like, well, essence of savoriness. “Savory” is one of those flavors that is hard to pinpoint - for salty, sweet, sour, bitter, we have archetypes - sugar, sodium chloride, lemon juice, and alkaloids, which you don’t taste on their own very often. As Barry Sharpless noted, he won’t taste a compound with a nitrogen atom in it - these are the bulk of our alkaloids, many of which are psychotropic (not nearly all, though). The best everyday example of a bitter compound I can think of is tonic water, which is bitter due to the alkaloid quinine.

Anyway, savoriness, or “umami,” as he put it, is hard to pinpoint. Those crystals he found came close, which were those of the much-maligned monosodium glutamate, or MSG:

This is a naturally occuring amino acid (vital, in fact, to the transaminase system in your body). Your intake is on the order of grams per day. The difference, some say, is in the mode and timing of ingestion. Eating a quarter pounder will give you ca. 3,000mg of glutamate, but the vast majority is not free glutamate. That is, it’s tied up in the proteins in the meat. That, and you’re taking it in with nineteen (possibly trace amounts of a twentieth) other amino acids, which don’t seem to cause the same spike in blood levels.

Many people have criticized MSG for being a potential allergen, excitotoxin (neurotoxin), and just generally bad because it’s a source of elevated sodium intake. It’s up for debate. We lean towards saying it’s safe. The famously conservative FDA, for example, still lets us sell it. Countless chemicals aren’t approved here that are approved even in Europe (no stranger to paranoia about food additives itself, as the GMO food controversy will indicate). Even the often-slandered sodium cyclamate is available in much of the rest of the world.

However, it merits looking into. Additionally, glutamate intake is being investigated as a possible marker (or etiological agent, you can’t really say yet) for obesity.

Whatever the dangers of glutamate are (and don’t get me wrong, they may be very real for some), they have been exaggerated. Very, very few people will break out in hives after eating glutamate in food. The closest anyone ever came to a “chinese restaurant syndrome” was in about one percent of a study population who took in three grams (dissolved in water, no food). This is an enormous dose, and most foods you eat (your Peking Chicken, for example), will come with ample other proteins to minimize the blood spike of glutamate. Jeffrey Steingarten, the lawyer-turned-food critic for Vogue, tackles this brilliantly in his essay, “Why Doesn’t Everyone in China Have a Headache.” It is available in his anthology, It Must Have Been Something I Ate (p. 91-99), which I recommend highly.

Enough about the dangers, let’s talk about how it tastes! You can get MSG over-the-counter at your grocery store! It is sold as “Accent” and is pure sodium glutamate. A few tens of crystals on the tongue tastes a bit salty at first, then transitions into something I swear tastes exactly like flavorless salty brothiness. You get that sort of ineffable bite right at the sides of your tongue and in your jowls that good Parmigiano-Reggiano or tomato with salt gives (both rich in free glutamate, not coincidentally). The sensation (I hesitate to use the word flavor; it is absolutely odorless and does not involve your nose; this is purely on your tongue) is astonishingly complex for such a simple, one-molecule “dish”. I think part of the reason we have trouble accepting “umami” as a taste is because it is not a one-note wonder like sweet, sour, salty, bitter. To misappropriate a choice phrase from another of Steingarten’s articles, savoriness wears a thousand faces. I have tried this tens of times with no ill effect. I still haven’t actually put it in my own food. All the rumor-debunking aside, it feels weird to add MSG to my own food. Eating it neat is apparently OK by my gastro-experimental calculus.

One last aside - perhaps because of the bad rap MSG gets (or, more likely, because it’s cheaper), some foods have taken to including “protein hydrosylates” or “autolyzed yeast.” These are just proteins broken down to their constituent amino acids. I don’t think they do anything to isolate or enrich it in glutamate, they just make it the free amino acid to do its mouth magic.

Have a good Memorial Day, see you Monday or Tuesday, depending on motivation levels. Bye!