Science It Up A Notch
Irradiated by LabRat
If you are a foodie or simply very interested in what’s in your food and how it tastes, you probably already know of the concept “umami”, the fifth basic taste along with salty, bitter, sour, and sweet. In Western countries the concept is usually expressed as “savoriness”. What fewer know is that umami has a single and very direct source; as sweetness as a sensation is triggered by simple sugars and their molecular imitators, umami is triggered by glutamates. Glutamic acid, a nonessential amino acid, is the natural source, and monosodium glutamate is the manufactured one. Glutamic acid is usually bound up in a protein in its natural form, but only free glutamates provoke the strong savory taste; foods with naturally high amounts of free glutamates are the ones that provoke the strongest sensation of savoriness. Many meats have a fair amount of free glutamates, as do tomatoes, mushrooms, breads and other yeast products, and especially many varieties of cheese- thus explaining the perennial popularity of a slice of pizza*.
Since humans seem to be strongly drawn to savoriness- soy sauce is another potent source of free glutamate, and it is one of the world’s most ubiqutous condiments, with tomato sauces being just as popular in other quarters of the globe- making sure a meal has sufficient glutamic acid content is one way to guarantee that otherwise boring ingredients will be delicious. Bearing that in mind, a markedly successful recipe we tried recently that doesn’t look like it would be all that tasty unless you know this particular fun fact:
Cheesy Eggplant Bake
1 medium eggplant, peeled
2 teaspoons salt
3/4 cup dry bread crumbs
1 tablespoon garlic salt
1/2 teaspoon pepper
1 egg + 2 egg whites
2 tablespoons olive oil, divided
1 large green pepper, chopped
1 medium onion, chopped
1/2 pound fresh mushrooms, sliced
2 (14.5 ounce) cans stewed tomatoes
6 ounces part skim mozzarella cheese, shredded1) Slice eggplant crosswise into 1/4-inch rounds. Arrange rounds in a colander in your sink and sprinkle salt all over them. Walk away for half an hour. When finished, “rinse under cold water and pat dry with paper towels.”
2) While eggplant is sitting, combine bread crumbs, garlic salt, and pepper in a shallow bowl or on a plate. In a separate shallow bowl, whisk eggs. When eggplant is done, douse each slice in the egg mixture. Then dip in the bread crumb mixture to coat. Shake off any excess and/or drippy-ness.
3) In a large skillet, heat 1/2 tablespoon oil over medium-high heat. Cook a few rounds until browned, about 2 minutes per side. When finished, arrange in 13×9-inch baking dish. Repeat for second batch.
4) Preheat oven to 350°F.
5) Heat last 1 tablespoon oil in same skillet over medium-high heat. Add green pepper, onion, and mushrooms. Cook until onion is softening and pepper is crisp/tender, about 5 minutes, stirring occasionally. Top eggplant with mixture. Add tomatoes on top of that, spreading evenly.
6) Cover with tin foil and bake 25 minutes. Remove from oven and take off tin foil. Sprinkle cheese on top and bake another 25 or 30 minutes, until cheese is melted and a little brown. Serve to applause.
We substituted zucchini for the peppers since I don’t care overmuch for peppers but I do like squash quite a lot.
High-scoring sources of glutamates in this dish: Mushrooms, tomatoes, mozzarella cheese, eggs, bread crumbs. Medium-scoring: eggplants and peppers, both nightshades and relatives of tomatoes, and zucchini as well if you use that. Delicious content: high to match. Meat necessary to create sufficient umami for deliciousness: none whatsoever. Much to our surprise, given that neither of us had ever had eggplant or an eggplant-containing dish before and were moved to rate it higher than “meh”, but there you go.
*If you think you are sensitive to MSG and a meal at a Chinese restaurant bothers you but pizza doesn’t… the MSG is not your problem.
August 10th, 2010 at 5:56 pm
Thanks for the MSG/pizza info. This explains why I can eat at one Chinese restaurant in town, but not the other, and that the stories I heard about the second restaurant are most likely true.
Ew.
August 11th, 2010 at 10:28 am
Looking at that recipe, I doubt that umami is the main thing that makes it taste good. You use two teaspoons of salt plus a tablespoon of garlic salt, which tends to be about half salt. And then you add cans of tomato sauce and lots of cheese, both of which have a very high salt content.
If you ate half of that dish, you’d be eating about three teaspoons of salt. Given that the recommended daily salt consumption is one teaspoon, that is probably enough to push the dish into ‘superstimulus’ territory, so of course it will taste good.
Actually, it does look like a good recipe. I imagine that it would still taste pretty good if you added no salt at all and just relied on what was in the cans of tomatoes and the cheese.
August 11th, 2010 at 10:42 am
Salt is like glutamates in that they both make things taste more like themselves; I’m sure the salt is doing its job in the same way the glutamates are, but most cooks already know about salt and that it works in more ways than just making things taste salty.
Given there’s no evidence whatsoever that extra salt does anything but leave via the kidneys unless you are already hypertensive- and neither of us are- I tend not to worry about keeping within the RDA.
August 11th, 2010 at 12:37 pm
Is the “umami” word Japanese in origin? Just out of curiosity…
August 11th, 2010 at 1:31 pm
Yep, the chemist who identified it was a Japanese scientist looking for the strong flavor in seaweed broth. Not terribly surprising, as the concept is a much more important in Asian cooking than Western.
August 11th, 2010 at 2:05 pm
Also worth noting that the 2tsp of straight salt does not go into the bread mixture or whatnot, but is instead used to pull moisture out of the eggplant. Some is absorbed, but the vast majority collects as salt water on the surface and is rinsed away.
August 11th, 2010 at 4:05 pm
Good post, but can we do something besides eggplant??? PLEASE?
August 11th, 2010 at 4:18 pm
Man up and make the recipe. Even Stingray loved it and made the leftovers disappear and he’s NOT a fan of eggplant.
August 11th, 2010 at 5:25 pm
I’m with you on the eggplant. They look so cool and interesting and taste so blah. I’ll give this one a try.
August 11th, 2010 at 5:29 pm
Yeah, I should have realized that some of the salt was going away.
If salt is not such a big deal, why do I keep reading so many articles with medical professionals and scientists talking about how much damage a high-salt diet does? I’ve even people saying that the current sodium recommendation is too high. Given that we evolved in an environment of salt scarcity, I always imagined that our bodies would not easily handle a constant surplus and would be harmed by it.
August 11th, 2010 at 6:53 pm
We are going to try it– have most of the vegs in the garden anyway. I do think I’ll use a “heavier” (more umami?) cheese, and maybe fresh tomatoes.
My Italian grandparents made simple sauteed eggplant in butter and a bit of olive oil as a veg– say, up to step 3. I still do.
I think I too will substitute squash. Low heat Capsicum doesn’t make it
BTW I CRAVE salt, eat tons, have low blood pressure– may be genetic.
August 11th, 2010 at 9:33 pm
Salt, along with saturated fat, has been a massive nutritional battleground for several years- and nutrition itself is a heavily political field because much of the funding comes from government grants. Government nutrition guidelines and the American Heart Association are finally starting to back away from the notion that saturated fat is inherently bad (as opposed to the forms of fats and what you eat them with plus dozens of question marks).
We didn’t evolve in an environment of high vitamin C either- though some ancestral groups lived closer to more fruit than others, as some lived with the sea and very salty seafood and sea vegetable diets- but both are normally excreted in excess, even massive excess, by the kidneys. I’ll add links tomorrow if I can find the time to the more recent “no difference unless you are already hypertensive” broad studies.
August 12th, 2010 at 8:08 am
Right: “no difference unless you are already hypertensive” . Libby, who is, is more careful.You just salt after instead of before.
August 13th, 2010 at 3:58 am
My wife has taught me that everything that I thought that I knew about eggplant is plum wrong. (Except for the color of the skin.)
August 13th, 2010 at 1:15 pm
LabRat — Having had this “debate” with irritating frequency, I’d be interested in those links as well.
Meanwhile, here’s a short paper which appears to support the notion that salt levels are pretty tightly self-regulated via excretion through the kidneys. (Too bad the authors didn’t include an abstract.) I suspect that the studies “showing” that salt is bad for you are mistaking correlation for causation, and in fact show that most unhealthy diets happen to be high in salt.
August 13th, 2010 at 1:37 pm
While time’s still at a premium, there’s a good primer on the whole history of the debate from Gary Taubes here. Taubes is not unbiased and is writing with a definite point of view, but he’s also detailing the history of the biggest and most influential studies, so the citations are there and anyone with a different point of view has a start to study/argue from in there.
What’s NOT in dispute is that approximately forty skillion factors influence blood pressure and heart disease, and designing a study that controls only for one of them with the rest neutral is probably impossible.
August 13th, 2010 at 3:10 pm
Thanks for the link!
August 15th, 2010 at 9:20 am
“You just salt after instead of before.”
This usually leads to using more salt than less to get the same taste according to most scientists and cooks. If I am cooking for my parents or someone I know has high BP I tend to use more spices and caramelization and or char to create flavors.
Listening to NPR the other month I heard the recommendations of a tsp and a half per day and find it easy to stay below that as long as I am cooking from scratch and not eating stuff from a box. Fortunately I really like scratch cooking.