NYU chemist Kent Kirshenbaum is an advisor for a environmentally minded company trying to make vegetarian steaks and burgers that cook up like the real thing.
The problem: For the sake of the planet, we’re all going to need to eat a lot less meat. A 2006 report by the U.N. Food and Agriculture Organization found that the meat industry contributes to 18 percent of global greenhouse-gas emissions, and that 26 percent of the world’s land is used for livestock grazing. A whopping 70% of grains grown in the U.S. are fed not to humans but to livestock, poultry, and fish. Japanese scientists have estimated that producing just one kilogram of beef generates more greenhouse gas than driving 155 miles. A single hamburger patty requires more water than two weeks of showers. And with rapidly rising meat consumption in the developing world, the World Health Organization predicts that the amount of meat produced annually worldwide will increase from 218 million tons in 1997-1999 to 376 tons by 2030.
The solution? Well, that’s complicated. As NYU chemistry professor Kent Kirshenbaum sees it, we have a few different options. One is simply to encourage people to, well, eat more grains and vegetables. (The average American consumes close to half a pound of meat per day.) There are also the tried-and-true plant-based meat substitutes, from seitan to tofurkey, which have long been embraced by vegetarians but traditionally haven’t had much success in winning over those who love sinking their teeth into a big juicy steak. “There are great burgers made out of mushrooms and black beans, which have some of the characteristics of a meat-based food choice,” Kirshenbaum says, “but they’re not tricking anyone.” Then, in 2013 came the first lab grown beef burger, cultured from stem cells in a Dutch lab and unveiled with great fanfare—and a $300,000 price tag. Since then, the cost of growing meat from animal cells has plummeted, and scientists say such a product could be available to consumers within 5 years. But there are still some kinks to work out—including refinements in taste—and Kirshenbaum and others have pointed out that, given the large amounts of industrial energy needed to fuel this method, it’s not clear that it will carry major environmental advantages over traditional meat production.
But what if there were yet another strategy? A way to make a product that really looks, tastes, smells, feels—even sizzles and chars—like meat entirely out of plants? That’s the technical problem Kirshenbaum’s been working on as a member of the scientific advisory board for Beyond Meat, a company that fashions everything from chicken tenders to Swedish meatballs out of pea and soy proteins. He’s also a co-founder, with Steinhardt food studies professor Amy Bentley, of the Experimental Cuisine Collective, a working group that brings together chefs and scholars to talk about food in a rigorously scientific way—with an eye toward educating cooks and eaters about the molecular basis of a nutritious diet.
NYU Stories talked with Kirshenbaum about the technical challenges, environmental considerations, and moral implications of using chemistry to cook up vegetarian delights aimed to fool even devoted carnivores.
As a chemist, can you explain what makes meat meat?
A lot of it is the way the proteins have been organized in bundles, the way the cells are associated with one another to make the tissue that creates a particular texture.
And the individual proteins provide a particular taste response as well. The amino acids that exist in animal tissue satisfy one of our very basic taste responses, which is umami—that’s what gives us a feeling of satisfaction when we eat a slice of steak. So it's a very complex set of components—which makes trying to create something to resemble it all the more daunting.
What are some of the main challenges? It seems like it would be tough to mimic the transition from raw to cooked, for example.
That's a lot of what we’re working on right now. It's got to undergo the proper color and texture transitions so that you’re thinking, “okay, it’s not cooked,” and then, “now it’s cooked and safe and I can feed it to my family.” Even if it doesn't necessarily correspond to the same types of transitions that are going on when we cook a real burger, it still will be a lot easier for everybody if it does a good job of resembling that process. When you obtain plant protein like soy isolates or something like that, you can hydrate it and cook it up, and it just doesn't have the texture that a slice of meat or ground meat will have. So we've been working on ways to improve the texture aspects of these plant proteins so that as they're being processed, they will have the same types of texture attributes as ground sirloin steak. And that has been a huge breakthrough. Of course there are a lot of other things that need to happen as well: The color must be appealing or nobody's going to buy it, and it needs to smell right when you cook it. And fundamentally it has to taste good. That's also really challenging because if your eyes and your nose are telling you "this ought to be a burger," then what your taste buds are telling you better correspond as well.
How much will that experience cost the consumer? Could these plant-based meat products have an impact in the developing world?
There are all different ways to look at it. I can tell you that the products from the company that I work with, Beyond Meat, are not hypothetical—they're in stores right now and the prices are competitive with what you'd be paying for a turkey burger or a beef burger. And presumably, as the processes get better and the market expands, the prices will continue to go down. How will it affect people in other countries? I think it will affect them in two main ways: first of all, the middle class population in a whole bunch of countries around the world is really increasing, and their food choices include more and more animal protein in their diets. If we can avert that, that'd be terrific. So as these people come into the middle class, let's get them to continue to have a primarily plant-based diet, but then give them something that would maybe be a little bit more satisfying or robust than they've had in the past. The other is, as we have a diminished burden on our food system and on our agricultural system, we may be able to free up resources so that we can do a better job of providing good food for a larger population locally. So it could help everybody, even those people who aren't shelling out the big bucks at Whole Foods to get this product.
Will these alternative options become more appealing as meat becomes more scarce—and, thus, expensive?
Boy, I sure hope so. I think a big problem with meat right now is that it's too cheap. I think the prices of meat should more accurately reflect its impact, and I think if we treated animals better, the prices would probably go up. Right now, major corporations are moving toward providing better environments for their animals—whether it's the chickens that lay the eggs for McDonald's or whether it's the pork that's used for the meat at Chipotle—and prices are going up. I also think people more and more will feel ethically that they want to avoid animal-based food. And for those people, I think we can provide a better product.
Beyond taste and texture, there’s a lot of suspicion around what people perceive as “science food” or “Frankenfood.” How do you counter the popular idea that anything that comes from a lab could be unsafe—or just not taste good?
My mother-in-law hates the fact that I'm working on developing new foods because she says that she doesn't want her food to have any chemicals in it at all. The thinking is that chemists don't belong in the process because chemicals don't belong in food—which drives me crazy because I teach biochemistry and all of our food is chemicals. That's all it is! There's no way to get rid of chemicals in our food. So we need to overcome that initial suspicion about chemicals being something to avoid. But going beyond that, I think you're right that there's a huge segment of the population who thinks that our foods should not be processed, engineered, or treated, and that any time you get technical experts involved in our food system, that's a problem. I think about this a lot when I think about feeding my own wife and kids. I love going to the farmers market and obtaining food directly from the grower. But I also recognize that many of the things that my kids enjoy and we think are "good" are intrinsically processed. Chocolate, for example, is a highly processed food but at this point we consider it traditional and in some contexts healthy. Much of the produce that we buy has already been subject to incredible manipulation. Bananas, for example, don’t have seeds anymore, after a massive transition from what these fruits were originally. I don't have any hesitation about giving my kids bananas.
How has the vegetarian community reacted to efforts to make plants mimic meat ever more convincingly?
I've been very curious about what the response would be in the vegan community especially. I could see vegans saying, “This is horrible, Why can't people really focus just on eating vegetables and fruits the way they're meant to be eaten?” But I've seen a lot of discussion on social media where vegans are really embracing these products, which I find really gratifying. I'm not a vegan myself, but if I can find ways to solve their cooking challenges, I think that's great. One of the things that I've been working on with students here at NYU is creating a substitute for egg whites, which is really, really tough. If you don't have egg whites, how do you make a meringue? The products on the market for cruelty-free meringues were horrible and full of nasty chemicals. But we found this ingredient used in traditional Middle Eastern cooking that’s been used to create frothy whipped-cream-like topping on pastries. It comes from a root called the soapwort plant, which was a brought to my attention by a Turkish graduate student working in my lab. We began looking at this stuff and realized that we could bake this whipped foam and turn it into meringue. And it turns out that we didn't have to go into a laboratory and synthesize something that didn't exist before—it's just a matter of being creative about the use of very traditional ingredients. How do we take pea plants and make them look like red meat? Well, that's a technical problem. Is the solution working with cherry juice or something? There's got to be a good way to solve that problem. And if we can find something that doesn't come out of a laboratory, that would be even better. We can do a much better job of using the ingredients that we have to create more healthful and more sustainable ways of serving food.
Can you imagine a future where farm-to-table type chefs would embrace plant-based meat made in a lab?
Oh, absolutely, yeah. I think that chefs are eager to take advantage of new tools that are being provided to them. If new farms open up in an area, chefs will jump in and say “Oh okay, now I can put something on the table that was only picked yesterday afternoon.” And that's great. But there's other chefs who are more than eager to take advantage of revolutions on the technical side as well. In fact we’ve been working, for example, with chefs who needed to borrow a high-speed centrifuge to separate oils out from ground nuts they’d been fermenting in ways that had never been done before. I think restaurants will take the whole plant movement forward and find ways to create dishes that didn't exist.