Science Friday - A Horn Of Potato Plenty | Adding Marbling To Fake Meat For An Extra-Realistic Bite

Episode Date: November 28, 2024

Just in time for Thanksgiving, a potato researcher explains potato varieties, potato nutrition, and some tubular tuber facts. And, irregular, fatty marbling gives meat a unique texture. Recreating that in plant-based products isn’t easy.A Horn Of Potato PlentyThe potato is a versatile vegetable—baked, roasted, fried, mashed—it can bring something to just about any menu. But, how exactly do these tasty tubers end up on our tables? We’ll give you a crash course in potato science, including how potatoes are grown (hint: not from seeds!) and what scientists look for when they develop new potato varieties.SciFri producer Kathleen Davis talks with Dr. Rhett Spear, assistant professor in the Plant Sciences Department at the University of Idaho. Adding Marbling To Fake Meat For That Extra-Realistic BitePlant-based meat products have evolved over the past few decades. You can find them in many forms, like sausages, deli meats, and faux chicken nuggets. During the holiday season, no plant-based meat is more famous than the Tofurky Roast, a round imitation turkey.Despite improvements in flavor for plant-based meat products, there are still lots of challenges to getting fake meats to mimic their real counterparts. One tough one is textural: instilling a marbling effect. This is the effect of irregular fat deposits, which occur naturally in animal meat.Plant-based meat has a uniform texture by design. Because each product is processed to be a certain way, the randomness and irregularity of fat pockets is taken out of the equation. But some food scientists are working on adding more of this meaty texture to plant-based meat.Joining guest host Kathleen Davis to discuss the challenges and possibilities for the next stage of plant-based meat is Dr. David Julian McClements, distinguished professor in food science at the University of Massachusetts Amherst.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Meat and potatoes are the stars of Thanksgiving, even if plant-based meat is on your table this year. We'll use the 3D printer to print like the fat-rich regions and the protein-rich regions. So it looks something like real meat. It's Thursday, November 28th. Happy Thanksgiving. You're listening to Science Friday. I'm SciFri producer Shoshana Bucksbaum. To improve plant-based meat products, food scientists are getting creative with how to add a more realistic texture.

to the eating experience. One big challenge is marbling, how to get irregular fatty bits into a product that's made to be uniform. We'll get to that story in just a bit, but first, the humble potato and how it gets from the farm to your dinner plate. Here's guest host Kathleen Davis. We're talking about meat and potatoes. First, the humble potato, a versatile vegetable, baked, roasted, fried, mashed, what can't they do? But how exactly do these tasty tubers end up on our tables? Joining me now to give us a crash course in the Science of Potatoes is my guest, Dr. Rett Speer, assistant professor in the plant sciences department at the University of Idaho, based in Aberdeen, Idaho. Dr. Speer, welcome to Science Friday.

Hi, Kathleen. Thanks for having me. Well, thank you so much for being here. I want to start with a little bit of potato. One-1. Can you tell us a little bit about how they grow? Absolutely. So unlike a lot of plants that grow from an actual little seed that you plant in the ground, most potatoes are what they call vegetatively propagated. So what that means is if you take a potato and you cut it into pieces and throw it in the ground, that it will grow another plant. And that new plant will be genetically identical to the parent plant. Okay, so let's back up here.

So if I have like a pile of potato peels and other bits, is it possible that a potato would grow from that pile? It depends on how big those bits are. If you have a decent sized piece, and as long as, you know, you look at the potato and you see those little divvets on the outside of it that we call eyes, those eyes are actually where the stems grow from. So if you have a piece that's big enough and it has at least one eye on it, you can plant that

piece. And as long as the conditions are right, you know, it's not too cold, it's not too wet, not too dry, that little piece will grow into a new potato plant. Okay. So I think most people are familiar with maybe two distinctly different potatoes that they might come across in the grocery store. We've got the white potatoes and we've got sweet potatoes. What is the difference between the two? So if you go back far enough into their family tree, so to speak, they are very, very distantly related, but more importantly, sweet potatoes are more part of the morning glory family and potatoes are in the solanacium family. So their potatoes are in the same family as like tomatoes and tobacco and eggplants.

Okay, so let's go back to our good old white. white potatoes, how did we arrive at the common potato varieties that we see in the grocery store? So I'm thinking russets, Yukon Golds, red skin potatoes, how did we kind of come to this conclusion of these are the ones that we're going to find at basically every grocery store? So a lot of that comes down to, you know, there's been something in their development that has been beneficial to the farmer or to the consumer. So a lot of these white potatoes, a lot of these white potatoes, lot of them will store fairly well and for a long time. Potatoes like Yukon Gold, you know, they have a really good taste and they're visually appealing. But most of these potatoes, while they do

have lots of good things that have got them into the grocery store, oftentimes they'll have, I don't know if you want to call them speed bumps in their growth that could be a bigger hindrance, but the farmers know how to grow them. They've been grown them for long enough that they know how much fertilizer they need, how much water they need, when to plant and harvest them, and what they need in the season. You have, I think, one of the coolest jobs out there. You help to develop new potato varieties. So as an expert in this, what makes for a good new potato? So we're always looking for things like efficiency and sustainability. We want to see potato varieties that will turn a better profit for growers.

So an example of this would be, we're looking for maybe potato varieties that use less fertilizer or are less impacted by stresses like heat or water. Things that will, you know, make that variety easier to grow or better to grow or something that will help the industry to be better.

Mm-hmm. And I suspect that you also want those potatoes to taste good. right? Oh, of course. So what are the factors that actually contribute to the flavor of a potato? So there's a lot of things that will actually contribute to the flavor, anything from the soil that it's grown in to the different chemicals and volatiles and things that are actually in the potato that vary by variety. So if you eat a russet potato, it's probably going to taste different than if you eat a Yukon gold or a red or a purple potato. So we talked a little bit about the people who are actually growing these potatoes. How does weather affect the growing process for potatoes? So weather is a huge

factor when it comes to growing potatoes. The plant, based on the weather, can kind of start growing and stop growing. I don't know if that makes sense, but if it gets too cold, the plant kind of just, it doesn't grow as fast. And if you have potato tubers that are already growing at that point, you know, they stop receiving nutrients also. So when the potato starts growing again, and especially if it starts growing really fast, you could have one end of the tuber that's a lot smaller than the rest of the tuber. And if you have tubers that maybe receive some kind of stress in the middle of the growing season, like it got too hot or the farmer didn't get the water on or something like that, you might have that plant stop growing or grow very

slowly. And once it can start growing at its full rate again, you might have a tuber that looks like a dumbbell. Okay. I don't know if I've ever seen a dumbbell-shaped potato, I have to say. Well, quite often, they'll coal those out. They'll pull them before they get to the store because they're not visually appealing. Nobody wants to buy that kind of potato. We talk about climate change a lot on this show because it tends to affect everything. Does climate change play a factor into how you are thinking about developing new varieties of potatoes into how these potatoes might grow. Absolutely. So we really want to find varieties that are less susceptible to like heat stress or water stress, that they kind of like they can handle it a little bit better than some of the varieties

that we currently use. So we do trials at the university where we'll stress these varieties on purpose. like we won't give them enough water or we'll give them not enough fertilizer. And we'll see at the end of the season how that affects the yield and the quality of those potatoes. So let's shift gears here back to nutrition for a minute. Potatoes get a bad wrap, I would say, for being unhealthy. But can you set the record straight for us? Are potatoes nutritious? Absolutely, they're nutritious.

potatoes actually have quite a bit of a lot of the nutrients we need like potassium and vitamin C and protein. So, you know, I used to know some guys that did long distance bike rides and they would actually cook potatoes, little potatoes, and just put them in a bag on their back. And as they were riding these long distance rides, they would eat potatoes because it gave them a lot of the nutrients they needed for those big expenditures of energy. What an amazing idea. I've never thought about that. I think a lot of the bad rap comes from how the potatoes are prepared. Because, I mean, you don't go to Thanksgiving dinner with just a potato and no butter or no sour cream or no bacon or you don't eat

French fries that are not cooked in oil. I have seen blue potatoes in the store, kind of a shocking site. Are blue potatoes different nutritionally from white potatoes? Yes. So there's been some research done that's looked at the nutrition of colorful potatoes like that compared to a white potato. And they do have higher concentrations of nutrients, of carotenoids and other things that our bodies need. And so colored potatoes really do have a little bit more nutrients in them than just a regular white potato. Okay. So as the potato expert, I have to ask you, do you have a favorite type of potato? You know, I really do like specialty potatoes or these colorful potatoes.

Our program released one called Huckleberry Gold, and it actually has a purple skin and a yellow flesh, and it is just excellent for making mashed potatoes. That sounds beautiful. Do you have a least favorite type of potato that we should be avoiding? Well, given my employment, I don't know if I should be badmouthed in the potato that I don't like so much. But there are some that I wish that we could replace. because they're not efficient to grow.

They take a lot of nutrients and water, and any little tiny hiccup will give you a bad yield or bad quality in the end of the season. Okay, so one little safety question to end us off here. Let's just say that I forgot about a potato in my pantry and it has turned green. Is it safe for me to eat that green potato? You know, that green usually doesn't go very deep into the potato.

So if you peeled it past the green, you'd probably be just fine. The potato plant does produce a toxic chemical called solanine that's usually pretty much concentrated in the leaves and the stems or the parts that we don't eat. But potatoes that have been left in the light can develop higher concentrations of that chemical. So I wouldn't recommend eating a green potato. I would probably peel that off first. But you'd probably have to eat a lot of them to get sick. Good to know. And thank you so much for being here, Dr. Spear.

Yeah, thank you very much. Dr. Rhett Spear, assistant professor in the plant sciences department at the University of Idaho based in Aberdeen, Idaho. After the break, the food science being done to make plant-based meats taste like the real thing. We'll be right back. If you've been or been with a vegan or a vegetarian at a Thanksgiving meal, It's possible that you've run into the famous Tofurky roast, a round plant-based imitation meat. You can find plant-based meats in a lot of different forms these days, like sausages,

deli meats and faux chicken nuggets. But there are still a lot of challenges to getting plant-based meat to mimic their real counterparts. A big challenge for food scientists is marbling, which helps give real meat. It's, well, meaty texture. My guest today is working on this very question. David Julian McClements, Distinguished Professor in Food Science at the University of Massachusetts Amherst. Welcome to Science Friday. Thanks for being here. Yeah, great. Thanks for having me. So what is marbling in meat scientifically? Yeah, so marbling is when you look at meat, you see these

white regions and red regions. And the whitish regions, so the regions full of fat, which is called adipose tissues, you have these fat cells that have a whitish appearance because they've stutter light quite strongly and they're surrounded by these red regions, which are the sort of fibrous, protein-rich regions. So for anybody who has had plant-based meat, they'll know that it can be a monotextural experience. You don't have those pockets of fat and those other irregularities because the fake meat is processed to be that way. So how are you and your team looking at adding marbling to plant-based meat? Yeah, we have a few different ways that we're trying to do it. One way it means 3D printing. we'd like create these edible inks.

So we have like an edible ink, which is a plant-based depose tissue. And then we have another edible ink, which is like the lean tissue, which has got a natural red color, like an ex-rat from beating it. And then we'll use a 3D printer to print like the fat-rich regions

and the protein-rich regions. So it looks something like real meat. So are you 3-D printing just those elements? Or can you 3D print like a plant-based steak in its entirety? Yeah, I mean, I think my goal was always to do a plant-based bacon because I'm a vegetarian now and I haven't eaten English bacon for years and year, and it was one of the things I really missed. So I've been trying to get my students to do

like a nice plant-based bacon kind of product. But you could also do like a roast beef or something like that as well or, you know, a turkey kind of product for Thanksgiving. Right. What are the biggest challenges with marbling and adding this texture to plant-based meat? Yeah, because I think if you look at real meat at a structural level, it's incredibly complicated. I think we're so used to these materials every day. We don't realize what's actually going on at the molecular level and the structural level. And so I think trying to mimic the structural architecture of meat, these little tiny micrometer size fat cells, which are coated by fossilities and proteins, so trying to mimic that with plant-based ingredients and get the same sort of

texture and taste and appearance and nutritional properties is really, really challenging. What have been the most successful strategies that you have found in your career? Yeah, do we use something called emulsion gels? They've got fat droplets in them, these very small little beads, which are full of fat, and we coat them with our sort of proteins. And then inside them we might put things like coconut oil, which will give like the solidity that you would normally get from the sort of large you would get in beast or other kinds of products.

So we can make a product that looks and feel it a lot, really deep of tissue. But the problem with using coconut oil is it's full of saturated fat. And saturated fat is not good for your health, especially like heart health. So we're trying to find alternatives for doing that to make it healthier as well. I would imagine another challenge is, you know, when you're turning a raw steak into a cooked steak, when you cook that item, there's different chemistry going on with that fat compared to the other parts of the meat. Is that something that you have been working on on addressing for plant-based meat? Yeah.

If you look at real beef, at room temperature, it's quite hard. Then when you heat it, all the fat crystals will melt and it will become softer. And that's sort of melting in your mouth's characteristic and be really important for certain types of food products. So we're trying to mimic that behavior, where you behave in one way at room temperature, when you heat it behaves very differently. So it releases the oil and then that lubricates your mouth and gives you a nice sort of juicy mouth feel. when you're consuming the product. How close do you think we are to having an effectively marbled piece of plant-based meat

available for purchase? We're getting closer. I don't think we're nowhere near there yet. And I think we still need to do a lot of science before we get there. But I think we're getting better and better at doing it. And there are some reasonably good products on the market now. So not next year's Thanksgiving, but maybe a decade from now? Possibly, possibly a little bit shorter than that.

Besides marbling, what other textual challenges to plant-based meat are you working on? Yeah, I think the marblins to do with the fat part of the meat, but it's also the challenges to do with the lean part of the meat. And the lean part of the meat is what could be, it's like chewiness in the mouth. And I think if you've eaten it a lot to these plant-based products, you know, like Impossible Burger on Beyond Meat Burger, they often are quite mushy when you buy it into them. So they break down too easily in your mouth.

So we're trying to make a product that would be more simealible, like a real meat product and how that behaves. So it retains some of its texture in the mouth when you're chewing it. And again, that's really challenging to do because kind of based ingredients are very, very different from animal-based ingredients. So you need to use all these structural architecture methods to try and do that. I have heard this argument a lot in my own time exploring meat alternatives where people say, why are you going for these ultra-processed fake meats when you can just eat lentils or beans or get your protein elsewhere? And I'm sure you've heard that a lot as well. So as a food scientist, why focus on making plant-based meats better?

Yeah, I think the ultimate objective is to address sort of greenhouse gas emissions and sustainability and biodiversity. So I think, you know, their meat and livestock production is a really big contributor to all those adverse effects on our environment. So we want to create this new generation of foods that are going to be better for our environment and also better for our health. But if you look at consumers, 95% of consumers are meat eaters. So we really need to target the meat eaters if we want to have a big environmental and sustainability impact. So we need to make a product that people don't need to make any lifestyle changes. They can just go to the supermarket, buy a product, it looks the same, it tastes the same, it cooks the things.

You don't have to make any changes, but you're having a big impact on the environment. Well, that's all the time that we have for today. I'd like to thank my guest, Dr. David Julian McCleman's, Distinguished Professor, in Food Science at the University of Massachusetts Amherst. Thanks so much for being here. Fantastic. Thanks for having me. And that's all the time we have for now. Lots of folks help make the show happen, including Emma Gomez, Sandy Roberts.

Robin Kasmor. Annie Nero. Tomorrow, we start our celebration of 33 years on the air. Over the next few days, you'll hear some of the stories listeners picked as favorites from our archive. And we'll start things off tomorrow with a 28, team conversation with actor and science communicator Alan Alda talking about his own Parkinson's diagnosis.

Thanks so much for listening. I'm sci-fri producer Shoshana Bucksbell. We'll catch you next time.