A man’s father died, and they were at the funeral. People were coming up and giving their eulogies, and the pastor asked if he could come up and say a word.

So the guy said, yeah, please, Father.

And so the pastor got up and said, “plethora.”

And the man said, “thank you, Father. That means a lot.”

So for those of you that don’t know, Michael Silver, Michael is what I like to call the most interesting man in the world.

He’s not actually the Dos Equis man.

He is a certified executive chef, a certified research chef, is a CCS, CEPC, CCE – like, he has done it all in the culinary world.

And beyond that, he’s worked for NASA, he’s worked for Apple, he’s taught Porsche race car drivers how to drive their race cars properly. He’s done acoustical engineering, he’s been a conductor, a composer, an author…. I mean, I could talk for an hour just about him.

But he’s got some things that he wants to teach you guys. So it is my honor and my pleasure to introduce Michael Silver.

Thank you. So welcome, and thank you all for coming. It’s really a great honor for me to get to talk to all of you guys. And today I’m going to talk to you all about taste and umami.

I’ve tried to balance this talk between the practical and the technical so that there’s something for everyone.

To begin, I just want to take a minute and talk about umami, savoriness, and meatiness. These terms are often confused with one another.

Umami is a basic taste on the tongue, and it signals the presence of protein. Savoriness is a flavor, not a basic taste perception; and it may or may not include umami taste. And meatiness is a complex flavor that’s driven by aroma, and it includes umami taste. And it also includes other organoleptic properties of foods like texture, color, temperature, and spiciness.

A meaty aroma has a lot of important volatiles, including trace amounts of animalistic compounds like skatole and indole, which smell really horrible on their own. But they’re essential for the complex flavor of meat. Umami provides a really important foundation, but it’s the volatiles in the fat that provide the identity and the complex depth of flavor.

This is like the difference between eating white sugar and a freshly baked chocolate chip cookie. There’s a lot more going on in the cookie than just sweetness, although sweetness is an important component. The same cookie without sugar wouldn’t taste right, and steak without umami would be similarly disappointing.

Now, I don’t know if you caught that, but I said it wouldn’t taste right. And what I meant is that the flavor wouldn’t be right. In the field of sensory science, taste is a specific set of sensory inputs from receptors on the tongue.

And today’s talk centers around our sense of taste.

In addition to our five basic tastes, a number of additional tastes have been proposed, including calcium, kokumi, water taste, and metallic taste. But only fat taste, called oleogustus, has achieved any widespread acceptance as a likely sixth taste.

To be considered a basic taste, a sensation must meet strict criteria: It must have a unique chemical stimulus, a dedicated receptor mechanism, a neural pathway to the gustatory cortex of the brain, and it must evoke a physiological response.

Fats are made from three fatty acids connected to a glycerol backbone. And what’s so interesting about fat taste is that our fat receptors don’t actually taste fat. What these receptors taste are fatty acids.

Luckily, we have an enzyme called lipase in our saliva that breaks down some of the fats while they’re in our mouths so that we can taste them.

And this is very similar to umami taste, because we also can’t taste proteins, but we can taste the building blocks of proteins, which are amino acids.

However, there’s a critical difference in that we’ve got enzymes in our saliva that break down some of the fats into fatty acids, but we don’t have enzymes in our saliva to break down proteins.

So that means that some of the proteins have to be broken down in the food before we put it into our mouths in order for us to taste umami.

Now, people tend to think of protein as muscle, like a steak, but proteins run everything in our biology, and this is true for all animals, plants, bacteria, and fungi.

Proteins are these long linear chains of amino acids that many people describe as beads on a string.

How many of you came to the Tuesday talk? A lot of you. Okay, so you’ve already heard me say that I prefer to think of them as candies on a string, because when they’re released from the amino acids, they come in different flavors.

Most amino acids taste sweet or bitter, but two of them, glutamate and aspartate, are umami flavored. And glutamate has a much stronger umami sense than aspartate. It’s also a lot more common in foods.

So, when we put something into our mouths, we subconsciously process information about how it might affect us, called the post-ingestive effects, and we make a decision about whether or not to swallow it.

Each basic sense sends this important, powerful message to our brain: Sweet sense signals that there’s quick energy in the food; Salty signals electrolytes; Sour indicates that there might be spoilage; Bitter indicates that there might be poisons in the food; Fat indicates that there is dense nutritional value in the food; And umami signals that the food has amino acids, and notably that it contains nitrogen, which is an essential building block of protein that’s not found in other food macronutrients.

Each of these tastes is triggered by a unique receptor on the tongue. Salty and sour receptors are ion channels, like this sodium channel. And bitter, sweet, fat, and umami are G-protein coupled receptors, GPCRs, which bind ligands. Ligands are small molecules or ions like glutamate that fit precisely into the receptor and cause it to transmit a signal into the cell.

Bitter receptors can detect thousands of different molecules, including alkaloids, many of which are poisonous.

Sweet receptors can detect hundreds of different molecules, including natural sugars like sucrose and glucose and fructose, as well as synthetic sweeteners and natural molecules that are not sugars but taste sweet.

How many different compounds do you suppose activate our sour receptors? One. All acids like vinegar, acetic acid, citric acid work by releasing a proton, a hydrogen ion, and that instantly reacts with water to create hydronium, and it’s that hydronium that actually activates our sour receptors.

Our fat receptors can detect dozens of different fatty acids.

Salt is a little complicated, but it’s worth a short detour here. We taste salt in two different ways. Our ENaC ion channels are what give us our clean salty taste, and they are very highly specific: they only respond to sodium and lithium. But they give us that clean taste, which is what we want in saltiness.

We also have a dirty salty pathway, which is much more complicated, and that mechanism responds to many different types of salts in foods, including potassium chloride and calcium chloride and magnesium sulfate. But these salts also activate our bitter and sour receptors, and they also have a trigeminal irritation that you may detect as a metallic taste.

High levels of sodium also activate this dirty pathway. That’s why if you have something with too much table salt, it will also taste bitter and unpleasant.

So the next time you guys are at home — gently cradling your salt cellar, take a few granules of salt and let them dissolve on your tongue, and just really think about what that taste perception is like, and then take a whole pinch of salt and put it in your mouth and see how that perception is very different.

And our last taste is umami. Now I’ve already told you that glutamate and aspartate trigger this receptor. Are there others? And the answer is no. These are the only substances that taste umami, and about 99% of our umami taste is driven by glutamate.

But our umami receptors also have a secret weapon. Do you want to know what it is? Well, before we get there, we’re going to play a little game, and I need a volunteer.

Please come on up! What is your name?

Linda: “Linda.”

Linda. All right. So, you now know that free glutamate is what drives our umami taste. I have a number of different foods here, and your job is to try to put them in order from what you think has the most free glutamates to the least.

Linda: “Oh my gosh.”

Any help from the audience?

“Kombu”

Okay, kombu is a good guess, but the answer is Parmigiano-Reggiano. Because this cheese is aged for so long, the enzymes in it have a long time to break down the proteins into free glutamate, and so it comes in an impressive 1,440 milligrams per 100 grams of food.

All right, so what’s number two?

Linda: “I’m gonna go dried shiitake, maybe.”

Okay, that’s also a very good guess. However, number two is dried tomatoes. Tomatoes naturally have a surprising amount of glutamate in them, and again, during the drying process, a lot more additional free glutamate is released.

Number three?

Linda, “I hear the audience is going anchovies.”

Anchovies, okay. All right, very good. So, anchovies, as you guys all know, are a staple umami ingredient. They also have an interesting multi-sensory side effect. Because we associate anchovies with saltiness, if foods contain anchovies, or even just the aroma of anchovies, we’ll think that it’s saltier than it is. So that’s a way that you can reduce sodium in certain foods without the person thinking that….

It’s kind of similar to how vanillin or vanilla aroma indicates sweetness, so we can reduce sugar in foods.

All right, what’s number four?

Audience: “Kombu”

[asking Linda] Do you agree?

Okay, so now we’ve got our dry shiitakes. Anytime that plants and fungi are dried or fermented, all sorts of chemical processes take place that change and amplify a lot of the taste and volatile components of the foods. Many mushrooms have a lot of free glutamate in them, some even more than shiitake mushrooms. But shiitake mushrooms also have a high level of enzymes in them, proteases that break down the proteins during the drying process, releasing a lot more additional glutamates. Especially if they’re dried at, like, 100 to 120 degrees slowly, then you get a lot of free glutamates.

All right, what’s number five?

Tomatoes have an impressive amount of free glutamates in them, more than most other foods. There are two interesting exceptions to this. One is grape juice, which has a very surprising amount of glutamates in it. Grapes have a lot of glutamates in them, and when they’re processed into juice, a lot more free glutamates are released. And the other one is the durian, which has about twice the amount of glutamate as tomatoes.

Okay, so number six?

Linda: “Well, I think, I mean, I’m kind of torn. I think some of these have come in a little bit lower than I thought they would actually. I’m torn between green tomatoes and kombu.”

Linda asks the audience: “What do you all think? You want to go beef? Who said beef? Shiitake.”

Okay…. Scallops. A lot of seafoods have a surprisingly high amount of glutamates, and scallops have two other interesting attributes, which we’ll discuss later in this talk.

They also contain a fair amount of succinate, which I talked about in the Tuesday talk, which adds a lot of additional interesting flavor attributes to it.

Number seven?

Linda: “Kombu.”

Fresh peas. So… you probably do not associate glutamate with peas, but close your eyes and try to imagine what peas would taste like if they had no umami in them. Interesting.

Number eight?

Linda: “Our beef, and what else? Kombu.”

Okay; so we already talked about mushrooms, and we know that they have a lot of free glutamates in them.

Number nine?

Linda and audience: “Chicken. Kombu. Kombu? Gotta be somewhere.”

Chicken. All right, so finally we have our first meat, and it’s relatively low compared to some of these other foods, but chicken also has another secret weapon. Do you want to know what it is? Okay, but before we get to that, what’s number 10?

Linda: “I’ve been, I’ve been wrong a lot. I don’t know, what do y’all think? The, the kombu.”

KOMBU! So, kombu is known for its high amounts of glutamate. This is kombu that is extracted into water, which is how we normally eat it. If we were looking at the number of just dried kombu by weight, then it would be the highest thing on the chart, but I made these all as we eat them, so that it would be a little bit more fair.

Okay, and then what do you think for the last two?

Linda: “I’d say, I think it’s actually in order, because I feel like beef actually is going to be the lowest.”

Okay, and you are correct. So, thank you for playing, and as your gift, I have this lovely bag of drinking chocolate. Chocolate actually has umami taste in it, and it was a lot easier to bring on the plane than a steak. Thank you.

All right. So, as I hinted earlier, glutamate is just part of the story. So, to fully understand it, I want to pause and just take a minute to talk about the G-protein couple receptor. So, GPCRs are not just for taste. They’re the largest class of membrane receptors for all eukaryotes, which includes all animals and plants and fungi.

Humans have around a thousand different known types of GPCRs, and each one is specific to a particular function. And because they’re used so heavily in our physiology, they’re the target of about a third of all medicinal drugs.

GPCRs allow us to smell and taste and see. They regulate our heart rate and our blood pressure, our metabolism. They are also integral to our immune system and our growth and our mood.

They are these specialized proteins that have a receptor on the outside of the cell that can bind to a ligand, like glutamate, and then they wind back and forth through the cell membrane seven times, and they can bind to G-protein on the inside of the cell.

The “G” in “G-protein” stands for guanine nucleotides, which acts kind of like an on-off switch inside the cell.

Umami receptors are made from two GPCRs that pair together and function as one unit.

So, when a glutamate molecule comes along, it binds to the receptor, and this causes the receptor to clamp down on it like a Venus flytrap. And funnily enough, it’s called a Venus flytrap receptor. This clamping down transmits a signal inside the cell, which creates a small umami taste.

Now, let’s look at a different GPCR.

Glutamate is not just a taste molecule. It’s the main neurotransmitter that’s used in the human body, and over 90% of the brain’s synaptic connections are triggered by glutamate.

The mGlu4 receptor that’s in the brain is extremely sensitive to even very microscopic amounts of glutamates. It’s much too sensitive to be used as a taste receptor. It would be firing constantly because we actually have small amounts of glutamate naturally present in our saliva.

But a modified version of this same receptor is found in the mouth, and it’s used as a backup umami receptor. So, biology is all about efficiency, and so rather than create a whole new receptor from scratch, the body simply truncates the mGlu4 receptor so that it can’t clamp down on the glutamate molecules. And this makes it about a thousand times less sensitive and perfect for detecting umami in foods.

So, we have finally come to perhaps the most important part of the whole talk. This little red pill is the secret to umami. Do you want to know what it is?

Video: “Do you want to know what it is? Umami is everywhere. It is all around us, even now in this very room. Unfortunately, no one can be told what umami is. You have to taste for yourself.”

So, this little red pill is a nucleotide, and just as amino acids make up proteins, nucleotides make up our DNA and RNA, and they’re also used for many other things in biology. The nucleotide ATP, for example, is the energy currency for all life on earth.

Now, there are two binding sites on our main umami receptor. The primary binding site which triggers the umami taste is called the orthosteric site, and “orthosteric” means “correct site.” There’s another binding site, however, called the allosteric site, and “allosteric” means “other site.”

Allosteric binding sites are found in many protein receptors, so they can allow binding at a site, they can enhance the binding, or they can prevent the binding. In this case, it greatly increases the affinity of the receptor to glutamate.

So, when nucleotides bind at the allosteric site, that causes glutamate to bind much more strongly at the primary site. This does two things.

First, it makes our taste receptors about a hundred times more sensitive to the presence of glutamate in foods. And second, it boosts the umami taste up to 18 times over glutamate alone.

So, these nucleotides are the key to enhancing umami, and knowing which food contains them, and being able to take advantage of that, will greatly help you improve the taste and flavor of the foods that you make.

So, if you’ll forgive me, I want to take just a couple minutes and go down the rabbit hole just a little bit to explain some important things about these molecules.

Guanylate, which is also called GMP, is one of these umami nucleotides.

Now, nucleotides all have three parts.

They have the nucleoside, guanosine in this case, and this part is kind of like the fingerprint, and it’s what determines how the molecule functions.

The next part is a sugar, ribose, in this case. Ribose, for example, is included in the nucleotides that make ribonucleic acid, RNA, and is very similar to the molecule deoxyribose, which is exactly the same, but it’s missing one oxygen. So, that’s deoxyribose, as in deoxyribonucleic acid or DNA.

And then the third part is a phosphate group, which is the acidic part of the molecule. Now, nucleotides may have one, two, or three phosphate groups attached to them. In this case, there’s just one, so it’s a monophosphate.

So, GMP, that stands for guanosine monophosphate.

Let’s take a closer look at the sugar, and you can see that it has five carbon atoms; so, it’s a pentose… “pent” meaning “five”, and “ose” meaning “sugar.” Glucose and fructose, by comparison, have six carbon atoms, so they are hexoses.

And note that the phosphate group is attached at carbon number five. So, that’s why it’s called a five prime guanylate, and you’ll see that on ingredient labels.

The phosphate group, however, could also be connected to carbons number two or three, but if it is connected there, then it will not be recognized by our taste receptors, and it won’t boost umami.

And this is important because most enzymes create five prime nucleotides, but in some commercial food production, like in some inexpensive soy sauces, for example, strong acids are used to break the nucleotides down from larger molecules, and this creates a random mix of two, three, and five nucleotides.

The effect of this is the soy sauce will have much less umami boosting power than one that’s made naturally with enzymes.

Inosinate, also called IMP, is another nucleotide that is very similar to guanylate, and it also boosts umami taste. IMP is found naturally in animal sources, like chicken and fish, and GMP is found in plants and fungi, like tomatoes and mushrooms.

So this small difference between them is very important because GMP boosts umami more than twice as much as IMP does.

Commercially, these two nucleotides are sold together as I plus G.

All right, so now I’m going to take a minute and talk about Laevus and Dexter, the glucose brothers.

Laevus means left, and dexter means right.

So when you say that someone is dexterous, you mean that they’re good with their hands, but what you’re really saying is that they’re right-handed.

Now many molecules can be right-handed or left-handed, and handedness makes a huge difference in biology. Most sugars in biology are right-handed. So when we say glucose, we mean dexter-glucose or right-handed glucose.

When you eat D-glucose, your body can metabolize it for energy, but an almost identical version is left-handed brother L-glucose, passes right through you. And so if you eat enough of it, you’ll get diarrhea because sugar is very hygroscopic and it will suck water into your colon.

So, I don’t know, maybe that’s why he’s called “Lefty Loosey.”

But even though we can’t metabolize L-glucose, our sweet receptors are very forgiving, and so both D and L-glucose will taste sweet. That means that a manufacturer could make a calorie-free candy or something with L-glucose, and it would still taste sweet, but we just have to be careful how much we eat.

Now hopefully you guys have all had your morning coffee, because there’s one more way that we talk about right and left with molecules, and that’s related to how they rotate polarized light.

If you make a solution of sugar and water and pass polarized light through it, the light will rotate either to the right or to the left, depending on the sugar. And the rotation direction isn’t necessarily the same as the handedness of the sugar. So while one right-handed sugar might cause a rotation to the right, a different right-handed sugar might cause an optical rotation to the left.

For example: D-glucose, which is the main sugar in all of biology, rotates light to the right. So another name that you’ll hear for it is dextrose, which means right sugar. So, it’s both a right-handed molecule, and it also happens to rotate light to the right.

On the other hand — see what I did there — its left-handed brother, L-glucose, rotates light to the left. So, even though L-glucose is glucose, it’s not dextrose.

And fructose is the opposite…. so, the right-handed version, D-fructose, rotates light to the left. And so another name for D-fructose is levulose, which means left sugar.

And as a last example of optical rotation, you’ve all heard of invert sugar. Invert sugar is just an equal mix of fructose and glucose. And you can make invert sugar by heating sugar in water with a little bit of acid. And this breaks the sucrose down into fructose and glucose.

Invert sugar has an opposite optical rotation from sucrose. And so that’s why it’s called invert sugar. And the invert sugar also will taste sweeter than the sucrose, even though it has the same amount of calories. And that’s because fructose is so much sweeter than sucrose is. And even though glucose is a little less sweet, the average is still a lot higher.

All right. So while our biology uses right-handed sugars, it uses left-handed amino acids. But our umami receptors are not forgiving like our sweet receptors are. So a right-handed or D-glutamate will not taste umami.

So you can think of this like single-use kitchen gloves versus a baseball glove. Sweet receptors are like kitchen gloves. So either hand will fit into them easily. But our umami receptor are like baseball gloves. So your right hand won’t fit into a left-handed glove.

Now, the reason that I’ve explained all these fascinating things about molecules is because when taste molecules are generated naturally, they will be in their correct version. So sugars will be right-handed and amino acids will be left-handed. Nucleotides will be five prime.

But some industrial processes like acid hydrolysis create mixes of correct and incorrect versions of these molecules. And the result of this is that the umami taste is significantly reduced from what it could be.

For example, in acid hydrolyzed vegetable protein, which is used in like instant noodles and bouillon cubes and some snack seasonings, soy, corn, or wheat are boiled in hydrochloric acid and then neutralized with sodium hydroxide.

And this is fast and inexpensive to do, but it lacks the depth of flavor that natural processes create. So if your package of soy sauce says hydrolyzed vegetable protein, then taste it against naturally brewed soy sauce. There’s a huge difference.

Now, I know what you may be thinking. “Why not just use more of it?” But the reason is because the acid hydrolysis process also leaves behind harsh and bitter byproducts and massive amounts of salt. And the salt is produced because, you know, when you combine hydrochloric acid with sodium hydroxide, they react together and form salt and water.

And I wouldn’t “lye” to you about that.

So if you use enough of this to make up for the weak umami, then the food will be inedible. And to make matters worse, these industrial processes also lead to a loss of kokumi.

So, the best way to understand kokumi, which is Japanese for “rich taste,” is to think of it like a thickness or a richness, smoothness, mouthfulness, even though these effects are actually metabolic hallucinations.

The most potent kokumi substances are small peptides, which are chains of two or three amino acids, which usually contain a glutamate molecule as part of it. And these peptides activate our calcium-sensing receptors, CaSR. And unlike taste receptors, which have a direct taste pathway, this receptor is actually a taste modulator… so, it amplifies sweet, salty, and umami tastes, and it also diminishes our bitter taste a little bit.

When the CSR receptor is triggered, the brain interprets this intensified signal density as a physical substance. So it creates a sensation of thickness or coating or body that isn’t actually physically there.

Kokumi also extends the temporal sensation. So, that’s why it creates this sense of smoothness or a lingering aftertaste in the foods.

Now glutathione was the first peptide that was identified to trigger the kokumi sensation. And because glutathione acts as a master antioxidant in all cells, it’s the most common kokumi peptide that we have. In sensory science, we use glutathione as sort of the baseline to measure all other kokumi compounds against.

Now the second example, which I call the scallop peptide, is 13 times more powerful than glutathione.

If you saw my talk on Tuesday, I said that amino acids link together by holding hands. This little gamma on here is there because in the case of these peptides, it’s like… rather than holding hands, one of the amino acids is grabbing the leg of the next amino acid.

Using enzymatic hydrolysis through aging or fermentation creates a lot of these kokumi peptides. But acid hydrolysis creates very low kokumi. And that’s why hydrolyzed vegetable protein tastes thin or watery compared to real stock.

Now there are a lot of ways that we can maximize kokumi in our foods:

Long simmering of broths breaks down proteins into small kokumi peptides and also free amino acids like glutamate.

During the aging of cheese, the endogenous enzymes break down casein proteins and again create a lot of kokumi peptides and free glutamates.

The mouthfeel of aged Comte, that creaminess of it, comes in part from these kokumi peptides.

Incidentally, you know those little crystals in aged cheese, those little hard crystals? So those are tyrosine, which is another amino acid. And tyrosine is actually bitter and it’s the least water soluble amino acid. So as cheese ages and loses water, they precipitate out and crystallize. And so that’s why you get those little hard crystals in there. While tyrosine itself doesn’t add to kokumi or umami, it does indicate that there’s been a high degree of breakdown of the protein. So you can expect that there will also be a lot of umami and kokumi in the food.

Fermented fish sauces, yeast extract, dry scallops, koji, soy sauce, alliums, and pureed legumes are all great ways to add kokumi to your foods.

Alrighty, so you’re now all experts in nucleotides and allosteric modulation. So let’s take a look at umami synergy in foods. On the left, we have some foods with varying amounts of glutamate. And on the right, you can see in some of the foods the amount of GMP or IMP.

So let’s start with the plants. As tomatoes ripen, the glutamate in content increases about tenfold, which is a lot. And then when they’re dried, a lot more free glutamate is released. Now tomatoes are also one of the few plants that contain a significant amount of GMP. And so this is what makes tomatoes such a powerhouse of umami.

Fungi are great sources of both glutamates and GMP, especially shiitake mushrooms.

Meat, as you saw earlier, has relatively low amounts of free glutamate, but some of them also are amplified by the amount of IMP that they have in them. So even though there’s not so much glutamate, they will still have a stronger umami taste.

This next section is things from the sea. Scallops have a strong umami taste, both from glutamates as well as from IMP. And as we discussed, kombu has a very large amount of glutamate.

Speaking of kombu, kombu was where glutamate was first identified in 1907 by Kikuni Ikeda. And second, how many of you have had kombucha? So, kombucha may not be what you think. It is not a fermented Chinese tea like they sell in the supermarket or that maybe you guys brew at home. It’s actually an unfermented Japanese tea, cha, which is made from kombu. So: kombu cha. And somewhere along the line, someone got it mixed up, and so we now call it kombucha (the Chinese tea which has a completely different name, which I’m not going to try to butcher).

So if you combine kombu with katsuobushi fish flakes, which have a lot of IMP in them, that greatly amplifies that umami taste, then you get the original umami bomb, which is why that combination has been in Japanese cuisine for centuries.

And last, let’s take a look at the cheeses. So the amount of glutamate in raw milk is about a tenth of what it is in an aged cheese like cheddar. Long-aged cheeses like Parmigiano Reggiano greatly increases glutamates and umami, but notice that they have no amplification from IMP or GMP.

The reason that we find IMP in animal products and GMP in plants and fungi is because IMP comes from the ATP that’s stored in the animal, and it’s very high in animals because we need it for energy for movement. After the animal dies, then the ATP is broken down into IMP.

GMP is found primarily in fungi, and it’s the result of the breakdown of RNA. Fungi are very fast-growing organisms, and they’re packed with RNA, and so when they’re dried, enzymes degrade that RNA into GMP.

Tomatoes are interesting. Most fruits and vegetables contain little or no GMP. Tomatoes, like most fruits, as part of their ripening process have a programmed cell death which is called senescence. And because of the way that this occurs in tomatoes, a lot of GMP accumulates.

Most of the glutamates in tomatoes are actually found in the jelly, and so the jelly of tomatoes has about 15 times the amount of umami in it as what you’ll find in the pericarp. So if you make a concassée, for example, it will be very low in umami. So if you really want to boost the umami flavor, then use the jelly in it.

And so now that we’ve seen all this raw data, I want to take a look at these ingredients again, showing you how they’re amplified by the nucleotides. So as you can see, the synergy between glutamates and nucleotides puts tomatoes and shiitake way off the charts.

So I’m going to pull everything back so that you can see it all in perspective. Interesting, right? And even though aged parmesan cheese has no nucleotides to amplify its umami, just the sheer amount of glutamates in it alone makes it the third highest thing on this chart.

So now let’s make it a little more interesting and look at umami synergy in some prepared foods.

So, hamburgers have a fair amount of umami in them naturally. If we add cheese and ketchup to that, then that increases the umami taste by about four and a half times.

Dashi has a lot of umami in it from the kombu and katsuobushi. If we add miso, you know, fermented soy to that, then that greatly amplifies the umami taste of it.

Plain chicken breast has a fair amount of umami from the glutamates and from the IMP that’s naturally in chicken. If we add a mushroom soy glaze to that, it’s almost three times the amount of umami taste.

And last, sugo finto, which is like a vegan bolognese, has a lot of umami because of the tomatoes in it. If we add dried shiitake to that, then it’s now the highest thing on this whole chart.

So by combining these foods together, we can really greatly amplify the umami taste that’s in them.

Who liked brussels sprouts as a kid? Okay, I was one of those weird kids too… I always liked brussels sprouts, even though my parents cooked them horribly, but… you know.

So the reason a lot of people don’t like brussels sprouts is: one, they’re bitter, and two, especially if they’re cooked badly, you know, that the thiols disassociate and create this sulfurous smell.

If we add MSG to them, then the bitterness is greatly decreased and the umami taste is greatly increased. So just a little MSG sprinkled on top with your salt really greatly improves the flavor.

If we add bacon to them, then the bitterness is a lot smaller and the umami is a lot greater. So that’s why this combination is so popular.

Because nucleotides like IMP and GMP are so powerful, you really don’t need to use very much. And this is a recipe that I got from Ajinomoto to boost the umami taste of mayonnaise. So, for 22 pounds of mayonnaise with 10 kilograms, you need 16 grams of MSG, but only one gram of I plus G. So just one gram in 22 pounds of mayonnaise.

This is a study that was done. On the left is pure MSG and on the right is pure IMP. The umami taste is pretty low with just MSG relatively, and then as you start adding IMP in, it greatly is boosted. And this study was with IMP, so this was with GMP, it would be maybe 2.3 times higher than this even. And then when you get down to the right side where it’s mostly IMP, then it starts to fall off again, because again, it’s the glutamates that actually create the umami taste. So if it’s 100% IMP, it’ll have very little umami taste to it.

Because of the way that this works and tastes, most manufacturers like Ajinomoto recommend that you use maybe 5 to 8% of I plus G (which is how they’re sold together), with MSG to boost the taste. And that is largely because I plus G is just so much more expensive than MSG is.

How many of you guys came in on an airplane? Okay. How many of you had a tomato drink when you’re on the plane? Only one person? Okay. Tomato is surprisingly popular on airplanes. In fact, a few years ago, Lufthansa reported that they sold 53,000 gallons of it in a year, almost as much as beer.

And the reason that is so popular is because the white noise on an airplane in an airplane cabin, which is about 85 decibels, suppresses our perception of sweet and salty tastes, but it amplifies our umami taste. So, while other foods and drinks may taste sort of bland and flat in the air, the tomato juice is very umami rich, and so it’s savory and delicious.

Who here adds MSG to their desserts? Okay. So, that’s pretty good. Add it to your vegetables? A few people. Your bread? Okay.

Now, who puts salt on their meat? Does it enhance the flavor?

“Yeah.”

Yeah. Do you add salt to anything else?

“Yeah.”

So, right, you add it to vegetables, bread, even desserts. What about acid? Do you add acid to your vegetables? Desserts?

Who here seasons with bitterness? Bitterness is a great way of enhancing depth of flavor in foods, and it doesn’t need to taste bitter. The same thing with spiciness. If you bring the level just barely to the perception level so it won’t taste spicy, it will really increase the depth of flavor of the foods. So, try that with bitterness sometimes.

So why do… and again, you’re a unique audience here… but why do most people limit their use of umami to things like meats and broths and sauces? The umami taste did not evolve to signal animal flesh. It evolved to signal protein, the protein that’s in all whole foods.

And the word umami means deliciousness because it is delicious.

In my Tuesday’s talk, I suggested for doing sensory training that you take two bowls of lightly seasoned broth and put a little MSG in one and taste them side by side. You can do the same type of experiment with Brussels sprouts or other vegetables. Add some MSG just to plain water and taste that, and then put a little bit of I plus G in it and see how that boosts the umami taste. And then try adding umami to desserts or breads or any other foods.

There are so many ways that you can experiment with umami and really develop your sensory skills. And having that deep, profound understanding of umami really is an invaluable skill in cooking and baking and recipe development.

So the next time you’re asking yourself, does this need salt or does this need acid? Also ask yourself, does this need more umami or better yet, does this need more deliciousness?

Now I’ll open the floor to questions. I saw someone in the back had a question earlier.

You’ll get more umami when you hydrolyze vegetable protein because this is breaking it down, but not as much as you would get if you used enzymes to, you know, like fermentation to create it.

So there’s, you know, if you have a chance to try some side by side, do. I mean, it’s like, you know, using vanillin versus using real vanilla, right? There’s a huge difference between them. And it’s not just the umami taste, right? There’s all kinds of compounds that get created in fermentation that are not going to be there if you use acid hydrolysis.

Wine is interesting. I’ve mentioned that grape juice has a lot of umami in it and wine actually has less. The chemical processes during fermentation, it does have umami for sure, but not as much as in grape juice.

Question: “If you’re going to explain to someone in one sentence the difference between umami and kokumi.”

Well, umami is a basic taste. So it’s, you know, it’s one of our five basic tastes. Again, there’s a direct pathway to the gastrointestinal cortex of the brain. And so it’s a very simple, you know, we have a receptor for it. It activates the G-protein inside the cell. It’s a very complicated process that happens, but basically that creates a direct signal to the brain that says umami.

Kikumi, even though it goes to the calcium sensing receptor, it’s not this direct message. It’s kind of like the way, you know, when I talked about the dirty pathway for salt.

In that case, it’s actually a little more complicated because there’s multiple receptors involved, but it’s creating this sort of dense signal with all this kind of noise. And so the brain is interpreting all that going on at the same time as the thickness in the food. So it’s that, you know, sensory hallucination of thickness and, you know, the temporal extension of it that’s not really there in the food.

And it’s not also, you know, with umami, it’s there to signal that there’s protein in food. That’s why we have that taste. And, you know, all animals have different tastes and smells and stuff that they have. Cats can’t smell sweetness or taste sweetness, for example. And vampire bats only have electrolyte taste. And so depending on the animal, they’re going to have very different perceptions of foods than we would.

But, you know, in the case of kokumi, it’s a little complicated, but it’s not signaling anything directly like umami is.

Anytime you’re breaking down proteins, you’re going to break down to free, you know, and again, like I said, every amino acid has its own taste. But, you know, and most of them are sweet or bitter. So you might wonder why we don’t taste so much bitterness in foods.

So even though the amino acids taste bitter, it’s not a very strong signal. It’s not like umami. Umami is a very powerful signal, especially if it’s amplified by an allosteric modulator like GMP. So anytime you do any process fermentation, slow cooking, you know, slow cooking, you know, with collagen that gets broken down, you know, collagen is primarily three amino acids.

We’ll talk about collagen another time.

But yeah, anything that’s breaking them down will create more umami and other taste molecules and kokumi as well.

Are we out of time? All right. I’m here. Come ping me if you have any other questions or email me or whatever. Thank you guys so much. I really appreciate it.