Short Wave - TASTE BUDDIES: The Origins Of Umami

Episode Date: April 7, 2022

A Japanese chemist identified umami in the early 1900s, but it took a century for his work to be translated into English. Short Wave host Emily Kwong talks with producer Chloee Weiner about why it took so long for umami to be recognized as the fifth taste.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. This story begins in Tokyo with a Japanese chemist named Dr. Kikunai Ikeda. The story goes that back in 1908, Dr. Ikeda was contemplating Dashi. This is Sarah Tracy, historian of food science. Dashi is the Japanese soup stock. Used as the flavor base of so many dishes, miso soup, ramen, Sukiyaki. Anyway, back in the early 20th century, Dr. Ikato was trying to figure out what made Dashi so delicious. He felt clear that he was tasting something that was not adequately described by the four accepted chemical tastes.

Those four tastes being sweet, salty, sour, and bitter. But in the dashi, Ikeda recognized something different, a distinct savory flavor. According to the story, he set out to isolate what this flavor was and he isolated it from kombu, which is a really common type of seaweed native to Japanese cuisine. I get to work on his dashi like a chemist would, distilling the flavor of this seaweed in a lab, removing compounds like manatol, potassium chloride, and the sodium chloride until a single substance began to crystallize, glutamate. Glutamate is just an amino acid, a building block of protein. And Ikeeda called the taste that comes from glutamate, umami. And in 1909, published a paper in Japanese in the Journal of the Tokyo Chemical Society. He wrote, It is the peculiar taste which we feel as umay, meaning brothy, meaty, or savory,

arising from fish, meat, and so forth. I propose to call this taste umami for convenience. Ikeeda had discovered a fifth taste, but it would take nearly 100 years for umami to be accepted by the broader scientific community. Why? Today on the show, as part of our taste buddies series, we'll talk to shortwave producer Chloe Weiner about this century-old delay between umami's identification in Japan and its recognition world. wide and ask why it took science so long to accept what's right under its nose. I'm Emily Kwong and you're listening to Shortwave, the Daily Science Podcast from NPR. Here on Team Shortwave, we've been looking into the science of taste. You may have heard our

episode on Sour. And today, Chloe Winer, shortwave producer, is going to bring us Umami. If you know, you know, but in case you don't, Chloe, what is it? Umami is often described. Umami is often described, as savouriness or sometimes just deliciousness. Yes, it is. Sarah Tracy says it has almost a physical quality to it. It's widely recognized by food scientists to have this particular quality of almost textural value. It isn't just taste receptors with an initial sensory impact.

Like, ooh, I get sweet. Ooh, I get better. Oh, I get salty. It also seems to have this kind of temporal play that other basic tastes. don't really demonstrate. And umami has been a big trend in American food culture over the last couple of decades, as I'm sure you know, Emily. David Chang, for example, the chef behind the mama fuco restaurants.

He talks about umami all the time. There's a chain called Umami Burger, an online grocer called Umami Cart where, uh, this is a special surprise. I made some kombu dashi for this taping. And I have a bowl of homemade miso soup right here in front of me. How does it taste, Emily? It tastes like it feels to have sunlight spread across your whole body. It's so warming and rich. Yeah, so given how popular and kind of buzzy umami is as a word,

I couldn't believe that Iqaeda pitched it as a fifth taste so long ago. Yeah, it was like over 100 years ago that he published that paper, right? Yeah, exactly. And that paper wasn't translated into English until 2002. So I was like, why? How is that possible? Yeah. So that's what I've been trying to figure out. The story that we heard earlier about him first, isolating glutamate from Dashi. It's kind of like a fable in the world of food and food journalism. It gets told a lot. But why the paper wasn't really recognized in the U.S. is complicated. It sounds like a science story. Yes. I mean, some of E. Kada's work was acknowledged in a really big way. After he isolated glutamate, he realized he had something.

delicious on his hands. And then naturally, he immediately commercialized it. He founded a company called Aginamoto and started mass producing a food additive called monosodium glutamate, or famously MSG. Hard eyes. MSG. I didn't realize this for years, but MSG and UMOMI are kind of the same thing. Emily, I didn't realize that until like a week ago. Chloe, we're such bad Asians. We're bad Asians. I know. Anyway, here's how Sarah Tracy explains the MSG-Umami relationship. Food scientists have talked for a long time about MSG as being kind of like the poster child, the purest, most chemically pure, that is specific, targeted way of stimulating what is now accepted as an umami taste response in the human body.

So MSG is to umami what sucrose table sugar would be to sweetness. Hmm. Straight shot of umamminess. Okay. And even though Icade his research didn't make waves in the U.S., his product, MSG definitely did. That was kicking around in the 20th century, right? Yeah. And there's this whole history of MSG's reception in the U.S. that could really be its own episode. But the very short version is that MSG became really popular. in Japan and the United States until this panic around MSG and so-called Chinese restaurant syndrome, which flared up in the 1960s and 70s. Yeah, I'm familiar with this. It's when, like, people dining at Chinese restaurants or eating foods high in MSG claim to feel ill afterward, even though modern food scientists haven't been able to prove that there's any kind of link.

Right. But back in the day, this idea was really widespread. And, you know, I think it was fueled in part by anti-Asian racism and xenophobia, but also this movement against pesticides and a general wariness of chemicals. That's MSG's reputation a century ago. What was going on with Ikeda's Umami research in all that time? Yeah, that's a good question. Knowing how popular and controversial MSG was in the U.S., it seemed really strange to me that Ikeda's work on Umami wasn't well known. Yeah. I mean, one reason I can think of is that the 20th century was a really tense time between the United States and Japan. There was World War II, Japanese internment, a lot going on. Yeah, so Iqaeda's research could have been just completely dismissed for that reason.

I think so, but there were other factors, too, dating back even further. Victoria Lee, a history professor at Ohio University, told me that after World War I, nutrition research was booming in Japan, and flavor was a big part of it. Fermented foods and seasonings like sake, soy sauce, miso were a large part of the diet in Japan and also a large part of the economy. And so research into the flavor components of those kinds of foods were an important part of rationalizing diet in Japan. By rationalizing the diet, Li means that the Japanese government was trying to make sure they could produce enough food domestically in case of shortages. There were a series of economic crises. There were concerns about self-sufficiency in the context of preparation for war.

So all in all, the prominence of flavor in Japanese nutrition research comes from those kinds of concerns. Okay, so research in Umami was bound up in like this broader need for nutrition research that was tied to the economy and what was needed politically at the time. Yeah, Victoria Lee writes about that in her book. It's called The Arts of the Microbial World. And speaking of Japanese nationalism, she brought up another possible theory about why Ikeda's work didn't translate, literally. Lee actually told me that it was strategic for some Japanese nutrition researchers to focus on areas that would be specific to or culturally resonant in Japan. What does that mean? Well, for example, Japanese nutrition scientist Suzuki Umetto.

He has a story about going to Germany to work with the famous chemist, Amil Fisher. and when he was about to return to Japan, apparently Emil Fisher told him, when you go back to Japan, work on something distinctive to the region like rice. Don't work on what everyone else is working on in Europe because labs in Japan wouldn't be able to compete with the labs in Europe that would be much better equipped.

And back in the day, it took a while for scientific papers and materials from Europe to make their way to Japan. So focusing on local resources was one way to get around that. Yeah. This historical backdrop, it makes sense why Umami would be unknown around the world. You have xenophobia during World War II and this nutrition research bubble surrounding Japan and World War I. But umami is present in a lot of foods. So why did it take American food scientists so long to realize or validate the existence of Umami?

Is it simply because Iqaeda was the only one who figured it out and his paper wasn't available in English? Not totally. It's not like no one had access to his findings. We know that Ikeda actually presented his Umami paper at the International Congress of Applied Chemistry, this conference in New York, in 1912. Oh, so he was promoting this work. Yeah, and we don't know exactly how the audience responded in that moment, but it's not like there was this massive body of research in the U.S. that emerged after his presentation. And then fast forward to the 40s and 50s, American chemical scientists like Ernest C. Crocker, working at pharmaceutical companies, had a theory about glutamate that actually challenged Decatur's. They thought that glutamate didn't have a distinct taste, but that it produced a sensation or maybe even an odor that could be duplicated through a combination of salty and sweet and sour ingredients. Okay, so word in the U.S. among these scientists is that Umami wasn't its own taste. It was some kind of high.

Right. And Sarah Tracy says at the time that scientists were still actively debating the criteria for what counted as a taste. And umami, at least for Crocker, didn't make the cut. Other reasons that I've come across for why English-speaking scientists weren't compelled by the idea of glutamate representing a fifth taste is one, just the weight of history, the enormous weight of millennia of tradition. The big four, you know, have had incredible resilience and cross-cultural kind of consensus around those four. So to break with that, I think anyone would have needed a lot of evidence to overturn that. But the evidence needed to overturn that did come about around the turn of the century. How did American researchers finally begin to embrace Umami?

Yeah. So a team at the University of Miami discovered that rats, and eventually humans too, have a specific glutamate receptor both in our brains and our tongues. And that hard biological evidence is what turned the tide. Yeah, I hear this and cool as it is, I can't help thinking, Chloe, that Iqaeda discovered this a long, long time ago. Yeah, and it took 100 years and a lot of corporate messaging and efforts from Agenamoto, Iqaeda's company, to work up enough research interests to get there. It's also important to point out that Aginamoto was very motivated to dissuade the anti-MSG fears in the U.S. because they were hurting the company's bottom line.

So shifting the focus to Umami, both scientifically and also culturally, was part of that. That makes sense to me. Like, we like to think of science as independent when actually some research is only possible when social forces change, when the historical planets align. and people are like ready or wanting an idea to be proven, even if it was proven a long time ago. Yeah. And it made me think more generally about what other ideas or research is out there that we aren't ready to hear yet. If you go back a decade or a generation, the thing that we take for granted as being normal and obvious wasn't normal and obvious. And so it's really valuable and fascinating for being able to empathize with other people's

perspectives or think cross-culturally because even our ideas, even the most fundamental cultural principles we live by, you know, they have a life and they were not always so. Sarah Tracy is the author of the forthcoming book, Delicious, A History of Monosodium Glutamate, Umami, and the Dysphoric Sublime. This episode was reported and produced by Chloe Weiner, edited by Giselle Grayson, our senior supervising editor, and backchecked by Catherine Seifer. The audio engineer for this episode was Natasha Branch. Andrea Kisick is the head of the science desk.

Edith Chapin and Terence Samuel are the executive editors and vice presidents of news. And Nancy Barnes is our senior vice president of news. Special thanks to Michael Gordon, Scott Montgomery, Kumiko Niomia at the Omami Information Center, and Masaki Uchida for their help with this episode. I'm Emily Kwong. And I'm Chloe Weiner. Thank you for listening to Shortwave, the Daily Science Podcast, from NPR.