Forever Fresh

Summary

Radiolab Podcast Summary: "Forever Fresh"

Episode Details:

• Title: Forever Fresh
• Release Date: January 31, 2025
• Hosts: Lulu Miller and Latif Nasser
• Guest: Nicola Twilley, Science Writer and Author of Frostbite

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Introduction to Frostbite and Food Preservation

In the episode "Forever Fresh," Radiolab delves deep into the intricate world of food preservation, guided by Nicola Twilley, a renowned science writer and author of the book Frostbite. Twilley's work explores the extraordinary measures humanity has developed to keep our food fresh, extending far beyond simple refrigeration.

Latif Nasser introduces Twilley, highlighting her extensive background in science journalism and her long-standing contributions to understanding food systems. Twilley remarks, “[01:29] It's too yummy. It looks so yummy,” playfully referencing her son's nightly apple ritual, which becomes a gateway to discussing the unseen processes that keep such fresh produce edible year-round.

---

The Role of Refrigeration: A Time Machine for Food

Twilley explains refrigeration as a "time machine" that slows down the natural processes of decay. “[04:26] It's just slowed down reality,” she states, emphasizing how lowering temperatures inhibits the growth of fungi, microbes, and bacteria, thereby prolonging the life of fruits and vegetables. This foundational concept sets the stage for a historical exploration of refrigeration's impact on food supply chains.

---

Historical Insights: Refrigeration During World War I

The conversation shifts to the origins of large-scale refrigeration efforts. Twilley recounts how, during World War I, Britain faced a critical shortage of food. In response, scientists developed methods to refrigerate apples for up to a year. “[06:08] England, they figured this out. Their first lot of Granny Smiths are coming out,” Twilley notes, illustrating the innovative yet unintended consequences of these early refrigeration techniques. Elderly apples inadvertently emitted ethylene, a plant hormone, which prematurely aged younger apples and disrupted other produce like peas and bananas.

---

Ethylene: The Dual-Edged Sword of Plant Chemistry

Ethylene emerges as a central theme in the episode. Initially identified as a pollutant affecting plant growth near gas street lamps, ethylene is simultaneously a vital plant hormone. Twilley explains, “[07:54] It tells a plant to move on to the next phase of its existence,” likening it to human hormones that regulate growth and development. This duality of ethylene as both a preservative and a natural plant signal underscores its significance in agricultural practices.

The hosts explore the paradox of ethylene usage: while it preserves one set of produce, it can negatively impact others. Latif Nasser reflects, “[10:14] They should just give us that to do that at home,” humorously suggesting consumer-level applications, only to acknowledge the broader complexities involved.

---

The Oracle of Delphi and Ethylene's Historical Mysteries

Twilley introduces a fascinating theory linking ethylene to ancient practices. She suggests that the priestesses at the Oracle of Delphi might have been inadvertently exposed to ethylene-rich gases from subterranean oil deposits. “[11:37] The Oracle of Delphi... were huffing ethylene,” Twilley hypothesizes, proposing that ethylene emissions could have influenced the prophetesses' trance-like states and perceived mystical abilities. This theory bridges ancient history with modern scientific understanding, highlighting ethylene's profound and sometimes mysterious impact on both nature and human culture.

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Ethylene in Modern Industry: From Agriculture to Plastics

Beyond agriculture, ethylene is foundational in the production of polyethylene, the most common plastic. Twilley points out, “[13:22] All plastic is made using ethylene,” illustrating how this simple hydrocarbon underpins a vast array of everyday products. The conversation underscores ethylene's versatility and its critical role in both preserving our food and shaping modern materials.

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Innovations in Produce Packaging: Extending Freshness with Technology

A significant portion of the episode focuses on groundbreaking advancements in produce packaging. Twilley discusses the evolution from traditional salad bags to high-tech solutions that mimic cellular respiration. “[22:34] It is a respiratory apparatus for lettuce. It is not a salad bag,” she explains, emphasizing the sophistication of these innovations.

Differentially Permeable Membranes: Twilley introduces the concept of differentially permeable membranes, inspired by cellular biology. These membranes control the exchange of gases—oxygen and carbon dioxide—thereby regulating the breathing rate of produce. “[23:16] People think of it as the wax on lemons, but it’s a nanoscale layer of something that is food,” she clarifies, debunking misconceptions about the technology's safety and functionality.

Historical Development and Future Applications: The development traces back to the 1960s when Jim Lugg applied controlled atmosphere technology from cold war submarines to agriculture. Twilley narrates how Lugg’s innovations allowed delicate salads to remain fresh longer by meticulously managing their atmospheric conditions. This leap from large-scale warehouse control to individual packaging revolutionized the availability and variety of fresh produce in urban markets.

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Future Possibilities: Non-Refrigerated Meat and Beyond

Looking ahead, Twilley and Nasser speculate on the potential for similar technologies to revolutionize meat preservation. “[29:54] They have product,” Twilley notes, indicating that while the technology exists, consumer acceptance remains a significant barrier. The idea of purchasing non-refrigerated meat might initially seem unsettling, much like the early reception of refrigerated foods.

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Conclusion: The Invisible Efforts Behind Fresh Food

The episode culminates with a reflection on the extensive, often invisible efforts that underpin the availability of fresh food. Twilley comments, “[25:17] Those regimes have nothing on what we have figured out for fruits and vegetables,” highlighting the unprecedented advancements in food preservation. Yet, she also points out the societal desire to perceive food as naturally fresh, masking the complex technologies that make this possible.

Latif Nasser concludes by acknowledging Twilley's invaluable insights, referring to her analytical prowess as "non-perishable."

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Notable Quotes:

• Nicola Twilley [04:26]: "It's just slowed down reality."
• Nicola Twilley [05:10]: "That is literally how cold works. It's a time machine. It slows everything down."
• Nicola Twilley [11:37]: "The Oracle of Delphi... were huffing ethylene."
• Nicola Twilley [22:34]: "It is a respiratory apparatus for lettuce. It is not a salad bag."
• Nicola Twilley [25:17]: "Those regimes have nothing on what we have figured out for fruits and vegetables."

---

Closing Remarks:

"Forever Fresh" offers an illuminating exploration of the science and history behind how our food remains fresh. Through Nicola Twilley's expertise, listeners gain a profound appreciation for the technological marvels that sustain our daily diets, revealing the delicate balance between natural processes and human ingenuity.

Transcript

[Latif Nasser]

Radiolab is brought to you by Progressive Insurance. Do you ever think about switching insurance companies to see if you could save some cash? Progressive makes it easy to see if you could save when you bundle your home and auto policies. Try [e-mail] Progressive Casualty Insurance Company and affiliates. Potential savings will vary. Not available in all states. Radiolab is supported by Betterment. Let's talk about you and your money. You like to relax. Every now and then, your money likes to work. And Betterment is the automated investing and savings app that makes your money hustle. While you're catching catching up on sleep, your money is up early, automatically reinvesting your dividends. Your money is a total workhorse. So you don't have to be because you've got Betterment, the automated investing and savings app that makes your money hustle. Visit betterment.com to get started. Investing involves risk. Performance is not guaranteed.

[Nicola Twilley]

Listener supported WNYC Studios.

[Latif Nasser]

Wait, you're listening.

[Nicola Twilley]

All right. Okay.

[Latif Nasser]

All right.

[Nicola Twilley]

You're listening to Radio Lab. Radio Lab from wnyc.

[Latif Nasser]

Here we go. Hug a doo. Here you go. What are you eating?

[Nicola Twilley]

It's a apple.

[Latif Nasser]

Can I have a bite of the apple?

[Nicola Twilley]

No. Why not?

[Latif Nasser]

It's too yummy. It's too yummy. It looks so yummy. I'm Latzif Nasser, this is Radiolab, and that is my four year old son who every single night before bed eats an apple. Which seems a little silly to say just because honestly, that's something I never thought twice about.

[Nicola Twilley]

All right. I'm good.

[Latif Nasser]

Yeah, great. First of all, until I had the conversation I'm about to share with you. It's such an honor for me to read this book.

[Nicola Twilley]

Thank you.

[Latif Nasser]

So this is Nicola Twilley. She's one of my favorite living science writers. She has written for the New Yorker, the New York Times Magazine, Wired, among other places. She hosts a podcast called Gastropod. And she just came out with a book that I had been hearing about from her for years. Honestly, ever since I first met her, you were already working on stuff that was like 10 or more years ago.

[Nicola Twilley]

I would say in total, it's coming up on 15. I really don't recommend that to anyone, but.

[Latif Nasser]

But it's an amazing book. It's called Frostbite. It's all about the crazy things that we do to our foods to get them from the farm to our table. And as the title suggests, a lot of the book is about refrigeration, which is, of course, why my son can eat a crunchy apple in January. But our conversation Actually ended up going way beyond refrigeration to some pretty surreal places and even psychedelic seeming technologies.

[Nicola Twilley]

Oh yeah, we are truly playing God with fruits and vegetables.

[Latif Nasser]

So today on Radiolab, I want to play this conversation with Nicola for you. It takes us from apples to salads to meat. It takes us from cold to warm, it compresses. Completely changed my idea of what it even means to call something fresh. But it started off actually just talking about all about the different refrigerated places that our food lives on its way to our mouths.

[Nicola Twilley]

Well, this is the food superhighway. It is the sort of behind the scenes series of spaces that we've built for our food to live in and move around in. And it's basically invisible and out of sight. And yet that is where roughly three quarters of everything that we eat on average spends time in that space. So, yeah, that's a good way of thinking about it. The other way of thinking about it is sort of a time machine of sorts.

[Latif Nasser]

Go say more about that.

[Nicola Twilley]

Yeah, well, because this is a funny thing that it took me a while to realize, but the way refrigeration works is it just makes everything slow. This applies across life, but like just.

[Latif Nasser]

In general or like on a cellular level.

[Nicola Twilley]

Well, so it's from the largest scale to the smallest scale. So when you work in a refrigerated warehouse, you are slower at doing the same tasks measurably than someone in an ambient temperature warehouse. But all of your cells are also working more slowly individually and your brain is firing more sl. It's just slowed down reality. And that's how it preserves food too. It just stops fungi, microbes, bacteria by slowing them down. And then for things like fruit and vegetables, which, like us, are alive, it just slows them down like it does us, so they breathe more slowly and they last longer.

[Latif Nasser]

Okay.

[Nicola Twilley]

So that, that is literally how cold works. It's a time machine. It slows everything down.

[Latif Nasser]

Now, I have to say, at this point, I honestly was not even thinking about the fact that fruits and vegetables are alive. But Nicola said as soon as you pick them, they're starting to die. And the whole point of the food.

[Nicola Twilley]

System is to prolong the death processes of fruits and vegetables.

[Latif Nasser]

And she says when it comes to what we do to delay that process, refrigeration is just the tip of the iceberg, so to speak.

[Nicola Twilley]

Oh, yeah, sure, yeah. Okay.

[Latif Nasser]

And to explain, she actually told me a story that goes back to the earliest uses of refrigeration back in World War I.

[Nicola Twilley]

So during the First World War Britain realized that it didn't have enough food to feed itself, and there was sort of a mass panic. So they set up this institute, and they start to work on apples. Long story short, they're able to keep apples refrigerated for a year.

[Latif Nasser]

What? I didn't even know that's possible.

[Nicola Twilley]

Oh, yeah.

[Latif Nasser]

Like, I get like, a month or two months or something like that. Oh, yeah, okay. Sorry I cut you off.

[Nicola Twilley]

England, they figured this out. Their first lot of Granny Smiths are coming out. You know, they went in in the autumn, they're coming out in the spring. There's headlines in the newspapers. Wow, wow, wow. But there's a problem. It turns out that elderly apples seem to emit something that is prematurely aging younger apples.

[Latif Nasser]

Spoiling their younger competition.

[Nicola Twilley]

Exactly. But they're also messing up other fruits and vegetables. They're causing pea shoots to grow all knobbly. They're turning bananas into. No one can understand it. Like, what is this apple power?

[Latif Nasser]

And it's something that's in the apple like that.

[Nicola Twilley]

It seems to be in the air around the elderly apples.

[Latif Nasser]

Okay.

[Nicola Twilley]

Total mystery.

[Latif Nasser]

But what they eventually realized is that in the air floating around these elderly apples is something called ethylene.

[Nicola Twilley]

Ethylene, it's a hydrocarbon.

[Latif Nasser]

It's one of the components in oil and natural gas. And in fact, a Russian scientist, earlier in the late 1800s, had discovered that plants, and in particular, trees living and growing near gas street lamps, would not grow as well. They would. They would. They were being poisoned. So it was known ethylene was as a sort of plant poison.

[Nicola Twilley]

But weirdly, the same thing that the street lamps are emitting, that is a plant poison, the plants are emitting themselves. How is this possible? But it turns out that ethylene is something else as well. It's actually a plant hormone.

[Latif Nasser]

Plants, it turns out, use ethylene as a sort of developmental signal sent between cells.

[Nicola Twilley]

So what it does is it tells a plant to move on to the next phase of its existence. Like if you spray ethylene over a field of pineapple plants, they all burst into bloom.

[Latif Nasser]

It's like puberty.

[Nicola Twilley]

Exactly the way that, you know, in our bodies, testosterone might tell your hair to grow.

[Latif Nasser]

Right.

[Nicola Twilley]

Like, you know, the apple is using ethylene to tell its little, you know, apple cells. Hey, time to lose your crispiness and your crunchiness and become mushy so that a bear will pick you up and eat you and scatter the seeds in the forest.

[Latif Nasser]

So the British scientists figure out how to block ethylene which for these apples that they're trying to store, it's like.

[Nicola Twilley]

They'Re telling them you must stay in eternal youth.

[Latif Nasser]

And it solves the rotting apple problem.

[Nicola Twilley]

But then they figure out how to use it for other plants, which also turns out to be an amazing tool because it turns out to be the key to ripening bananas. So a banana, if you want to harvest a banana and grows in a tropical country and you want to eat it in a non tropical country, you have to harvest it when it's green and unripe and refrigerate it. And then you get it to the destination. It's not gonna ripen on its own.

[Latif Nasser]

Oh, see, I knew that part, but I didn't know that's like the switch to turn it on on the other side.

[Nicola Twilley]

That's the switch. Ethylene is the cue to the banana to be like, great, now I'm gonna ripen and become a yellow, squishy banana. And then you have like 48 hours to get it to the grocery store before it, you know, starts turning into banana bread.

[Latif Nasser]

Yes, that's right. Right, right, right.

[Nicola Twilley]

So.

[Latif Nasser]

And wait, and so, okay, so you said it ripens apples, it ripens bananas.

[Nicola Twilley]

It ripens bananas and avocados. It keeps celery white, prevents it from going green, it turns lemons yellow and oranges orange. I mean, every lemon you buy, for example, has typically been blasted with ethylene to be yellow. And it turns out if you expose root systems to ethylene, they get bigger. So tomatoes, for example, will have their roots dipped in ethylene before they're planted. I mean, our whole fruit and vegetable world is built on using ethylene to control fruit and vegetable responses.

[Latif Nasser]

They should just give us that to do that at home. They should just give us the green bananas and a little pack of ethylene, and then you could just do it at home.

[Nicola Twilley]

Well, I think here's the problem. Latif turns out to also be super fun to huff.

[Latif Nasser]

No. Okay.

[Nicola Twilley]

It was like the party drug of the 1920s. It was really. Yes.

[Latif Nasser]

Real quick. The story is that these scientists who had discovered ethylene, you know, they did.

[Nicola Twilley]

What scientists always do. They huffed some of it themselves.

[Latif Nasser]

Mm.

[Nicola Twilley]

And it's an amazing paper. You can download it, you know, and read it in the Journal of the American Medical Association.

[Latif Nasser]

And what does it say?

[Nicola Twilley]

They're like, we felt a sense of well being and exhilaration, but you can tell that they are having the time of their life and one of their friends just can't stop GIGGLING which they report. One of them says, his report is like, I felt such bliss that I would be satisfied to lie down under the influence of this drug for the rest of my life.

[Latif Nasser]

Just, this is just one more reason to buy apples, you know?

[Nicola Twilley]

Well, so the reason I got.

[Latif Nasser]

So just one more historical note about ethylene and then we'll get back to food. I swear, I just can't resist. So it turns out that as Nicola was researching this book, she came across a very fascinating theory.

[Nicola Twilley]

The ethylene is what the priestesses at the Oracle of Delphi were huffing.

[Latif Nasser]

What?

[Nicola Twilley]

The Oracle of Delphi, of course, was one of the most famous oracles of ancient Greek history. And anyone who was anyone would go there and ask for advice. When should they plant their crops, should they invade their neighboring country, whatever. And the way it worked was a priestess would hear your question. They would go down into this little subterranean cave under the temple where there was a spring, and they would quote, unquote, you know, commune with the oracle and drink from the spring. And then they would relay a message to a priest who would then interpret that back to the person who was asking the question.

[Latif Nasser]

Anyway, couple decades ago, the Greeks were wanting to build a power plant over the same area. And a geologist who was studying that land discovered that this area had oil in it underneath the spring. And it seemed like some of the ethylene was sort of off, gassing into that spring and into that cave. So the theory is the priestesses at.

[Nicola Twilley]

Delphi were huffing Etheline. They were talking and excited and incoherent sort of gibberish. And then the priest was relaying that message. That's what was happening. This plant hormone that is a hydrocarbon that is, you know, turns out to also be the real oracle.

[Latif Nasser]

Right? That's the real oracle.

[Nicola Twilley]

But, yeah, it's also, I mean, I was like, wow, ethylene is so powerful. This is incredible. And then it turns out that the fruit and vegetable use of ethylene is like this tiny, tiny little drop in the ocean.

[Latif Nasser]

Because compared to what?

[Nicola Twilley]

Plastic.

[Latif Nasser]

Huh?

[Nicola Twilley]

All plastic is made using ethylene. It is the building block of polyethylene, which is everything. So basically, this is why ethylene turns out to be the most produced organic chemical in the world.

[Latif Nasser]

Wow.

[Nicola Twilley]

Because it is the bedrock of all plastics. And so we're making this oracular fruit and vegetable messenger. We're using it to make plastic bags.

[Latif Nasser]

We're going to take a quick little break. When we come back, we're going to shift from Apples to arguably an even fresher food. And we're going to talk about, believe it or not, plastic bags.

[Nicola Twilley]

Foreign.

[Latif Nasser]

This is Radiolab. I'm Latif Nasser. We are back talking to Nicola Twilley about how the food we eat gets to our tables. We are going to move away from apples and ethylene and ancient Greek prophecies to a kind of surprisingly futuristic technology stolen partly from nuclear submarines in the form of a certain kind of plastic bag. Salad bags that holds salad.

[Nicola Twilley]

Well, first of all, one thing to understand about salad is until the 1920s, no one bothered with it. It was pointless.

[Latif Nasser]

What do you mean?

[Nicola Twilley]

Well, at this point in human history, people are moving to cities in the United States, and it's really hard to get people a salad when it's not grown nearby and you don't have refrigeration. So salad was just really like, if you were super rich, you might have a nice salad of an evening. But it was not a part of people's lives until the iceberg variety is discovered. And it's sturdy enough that if you bury it under a crap ton of ice, you can ship it across the country and you're going to be able.

[Latif Nasser]

To sell it, which is where it gets the name iceberg lettuce, because as.

[Nicola Twilley]

It travels, it's just these train cars full of lettuce covered in a mound of ice. So iceberg is the only lettuce that most Americans could eat for most of the 20th century. And then what happens is a guy called Jim Lugg.

[Latif Nasser]

In the 60s, the 1960s, Jim Lugg was working for a salad baron in the Salinas Valley in California, and he was trying to help them figure out how to sell more salad and send it more places. Now, right around the same time, Whirlpool.

[Nicola Twilley]

The company has come up with some new technology that was spun out of cold war nuclear submarines. Cold war nuclear submarines stayed underwater for a really long time. And so they had to get really good at controlling the atmosphere.

[Latif Nasser]

Like within the sub. Yeah, yeah.

[Nicola Twilley]

You know, how much oxygen and how much carbon dioxide. And Whirlpool had developed controlled atmosphere warehouses. So.

[Latif Nasser]

So when Jim Lugg learns this, he's like, wait a second. In addition to keeping things cool, if I could control the atmosphere of the salad, if I could control how every bit of the salad is breathing, maybe I could slow down its decay process.

[Nicola Twilley]

He's like, we need to take this thing that you can control the atmosphere in a building but for a bag.

[Latif Nasser]

Because then there'd be all kinds of delicate, leafy Salads that could survive better being shipped across the country.

[Nicola Twilley]

And he comes across a polymer who's like, oh, yeah, differentially permeable membrane. That'll do it.

[Jeremy Bloom]

Okay.

[Nicola Twilley]

And so what differentially permeable membrane is. Is something that we have in every cell in our body, which is. It's just a membrane that.

[Jeremy Bloom]

So this is a little cartoon fly. Oh, here are some fish flops I made for our fish flop episode. I bought a fish and then I, like, flopped it around. So my name's Jeremy Bloom. I'm a sound designer here at Radiolab. You don't often hear my voice on the show, but sometimes you do. That's me doing a dolphin. You just don't know it.

[Latif Nasser]

This is a whale.

[Jeremy Bloom]

Sighing Every time I sound design an episode of Radiolab, I spend hours or days poring over these teeny little details that go into the sound of our show. So, like, if we're thinking about sound that we want to add to a story, we could just say, oh, it's daytime. I want to hear some birds. But there are so many other things that. That can indicate, like, are they birds after a rainfall?

[Latif Nasser]

Where are we?

[Jeremy Bloom]

What season is it? What time of day is it? At Radiolab, we take sound design as seriously as we treat the facts of our stories, because we know that those sounds. There's the sound designer, Walter Murch, I really admire, and he talks about how most of us humans have a sense of sound in the womb for three months before we develop any other senses. So in a way, it's our most primordial, our earliest sense, which is maybe why I think sound over the other senses has the potential to kind of like tap into our inner emotional selves. We really tried to draw from that in some way for every story we make. And the whole reason why we do it and why we're able to do it is because of you. Your financial support lets us invest in stories and sounds that nobody else can make. If you rely on Radiolab and the kind of work that we create, one of the best ways to support our work is to become a member of the labor. The Lab is our membership program where you can access exclusive perks and benefits like ad free listening, bonus content, our full archive merch, and so much more. To become a Lab member and support radiolab, go to radiolab.org join.

[Tresa]

Radiolab is brought to you by BetterHelp. Every January, you get an entirely new year ahead. 365 blank pages. You get to fill with whatever you want. You can add a plot twist. You could add a love interest. Maybe you want a whole new chapter with a family member. However you want to write the story of 2025, BetterHelp is here to help you make the moves you want. And with BetterHelp, it is fully online making therapy affordable and convenient. Serving over 5 million people worldwide, you can access a diverse network of more than 30,000 credential therapist with a wide range of specialties for any plot point in your story and easily switch therapists anytime at no extra cost. Write your story for 2025 with Better Help. Visit betterhelp.com Radiolab to get 10% off your first month. That's BetterHelp H lp.com Radiolab.

[Latif Nasser]

Radiolab is brought to you by Progressive Insurance. You chose to hit play on this podcast today. Smart Choice make another smart choice with Auto Quote Explorer to compare rates from multiple car insurance companies all at once. Try [e-mail] Progressive Casualty Insurance Company and affiliates not available in all states or situations. Prices vary based on how you buy. Radiolab is supported by Rocket Money Managing finances can feel complicated and time consuming, right? But it doesn't have to be. Rocket Money is a personal finance app that helps find and cancel your unwanted subscriptions, monitors your spending, and aims to help lower your bills so you can help grow your savings. See all of your subscriptions in one place, and for those you don't want anymore, Rocket Money can help you cancel them. Rocket Money's dashboard also gives you a clear view of your expenses across all of your accounts and can help you easily create a personalized budget with custom categories to help keep your spending on track. Whether your goal is to pay off credit card debt, put away money for a house, or just build your savings, Rocket Money makes it easy. Cancel your unwanted subscriptions and reach your financial goals faster with Rocket Money. Just go to RocketMoney.comRL today that's RocketMoney.comRL.

[Nicola Twilley]

Well, you know, know to let out oxygen or take in oxygen preferentially at a particular rate.

[Latif Nasser]

So in the mid-1970s, these scientists, taking inspiration from the cells inside living things.

[Nicola Twilley]

Figured out how to do it. You layer together these membranes, one that lets in oxygen at the right rate, one that lets out carbon dioxide the right rate, one that lets in water vapor at the right rate or out at the right rate. You know, you just kind of sandwich these all together, plus, you know, a layer for the label and a layer for some just so these things are like a minimum of five layers, sometimes more thick, delivering a controlled atmosphere inside that bag it is a respiratory apparatus for lettuce. It is not a salad bag.

[Latif Nasser]

That is crazy. But your point, and I gotta say, like, I just grabbed one of these just a second ago from my own fridge and like, it feels like I'm holding something between like an advanced technology and a living cell.

[Nicola Twilley]

This is one of the things that, you know, people who study fruit and vegetables sort of impressed upon me is like a baby lettuce. You're harvesting it when it's so tiny that there's only maybe five true leaves on the plant. And it is breathing so fast. It's such a tiny. It's a little baby.

[Latif Nasser]

Oh my God.

[Nicola Twilley]

And because it's breathing that fast, it is going to die. It's gonna burn through all of its resources and it'll turn into green slime. So you have to slow down its breathing.

[Latif Nasser]

You're giving me a vision of like someone, grocery store, with the like defib paddles on, like a little piece of spinach or something.

[Nicola Twilley]

It's life support. Honestly. When you visit the labs of the people who are doing this research, all the fruits and vegetables are like hooked up to monitors and you can measure how fast they're breathing. You feel like you're in the icu. It is like.

[Latif Nasser]

That's so weird.

[Nicola Twilley]

It's so weird. I never had a sense of my fruit and vegetables being alive. And now I'm sort of like, wow, are we taking care of you? Are you okay? You need something?

[Latif Nasser]

Yeah, right, Serious. Anyway, point is this seemingly simple plastic.

[Nicola Twilley]

Bag, it was like this transformative salad technology. People went from eating iceberg to like the salad revolution we live in now. Because you had this life support technology in the form of a plastic bag.

[Latif Nasser]

Who would have thought that that was more than a bag that just looks like a bag?

[Nicola Twilley]

Well, so this is actually a really interesting bigger point is. Cause the food industry goes to this enormous effort to keep our food alive, right? We are really good at prolonging the life of fruit and vegetables. You know how all those Silicon Valley billionaires are like, injecting themselves with young people's blood and whatnot?

[Latif Nasser]

Yeah, yeah, yeah, yeah.

[Nicola Twilley]

Like they. Those regimes have nothing on what we have figured out for fruits and vegetables. But at the same time, they don't want you to think about that. Cause people are weirded out. Like, what do you mean my apple's a year old? What do you mean my lettuce leaf is a month old? I don't want that. That's not right. That's not fresh. And so they have to go to all this effort and then make it invisible, tow it like it's fresh. It was just picked yesterday, you know, of course it's fresh. And so one of the most exciting technologies I came across is it's like Jim Lug 2.0, Mr. Salad Bag 2.0. He took, you know, something that was a building size technology and made it a bag size technology.

[Latif Nasser]

Yeah.

[Nicola Twilley]

These guys have taken something that's a bag size technology and made it like a nanoscale spray on layer size technology. So they have figured out how to create this differentially permeable membrane, this layer that lets in the right amount of oxygen, lets out the right amount of carbon dioxide. They have figured out how to create a spray that structurally does that out of lipids.

[Latif Nasser]

Lipids are basically just like a fat molecule in our body. And they're the actual thing that cell membranes are made out of.

[Nicola Twilley]

Literally.

[Latif Nasser]

Wow.

[Nicola Twilley]

And it's the way the guy who invented it, he spent his PhD figuring out how to spray paint particles on solar panels to make them more efficient at harvesting light. And it has to do with how they dry and the little structures that assemble as they dry. Same deal with this spray on fruits and vegetables is to do with how it dries and the little structure it creates as it dries.

[Latif Nasser]

So how would it. So you would just spray an apple and then you wouldn't have to refrigerate.

[Nicola Twilley]

Correct. So when I went there.

[Latif Nasser]

Whoa.

[Nicola Twilley]

I went into a room where there were red bell peppers at room temperature, and they had been there for eight weeks. So if you left a red bell pepper on your countertop for eight weeks, you can imagine it would be a pretty sad looking thing.

[Latif Nasser]

Shriveled and not good.

[Nicola Twilley]

Maybe even moldy. Not something you were gonna eat.

[Latif Nasser]

Yeah, yeah, yeah, yeah.

[Nicola Twilley]

And the ones. The comparison ones, you know, that hadn't been sprayed. That's how they looked. They were gross. You weren't gonna eat them. The ones that had been sprayed, you weren't gonna, like, cut them up and dip them in hummus. It wasn't like crudidae platter time.

[Latif Nasser]

Okay.

[Nicola Twilley]

But it was definitely stir fry time. It was like they were fine. You know, they were the kind of thing you'd look at in your vegetable drawer and be like, I should use that.

[Latif Nasser]

And this thing doesn't have a taste.

[Nicola Twilley]

No. It's a nanoscale layer of something that is a food. Like, it's like a fat. So it's not. But it's. You know, people are like, oh, you spraying it in fat, it's like zero calories, it's so thin. But it's not a chemical. I mean, it is a chemical in the sense that everything is chemical, but it's not a, like, weird chemical in the sense that people, when you tell people it's a coating, they think of like the wax that you get on lemons and stuff.

[Latif Nasser]

I was thinking of. Yeah, yeah.

[Nicola Twilley]

No, it's. I mean, I licked these bell peppers. There's nothing.

[Latif Nasser]

Okay, okay. There's nothing, as I usually do around bell peppers that I see in the wild.

[Nicola Twilley]

I asked permission first.

[Latif Nasser]

Oh, yeah.

[Nicola Twilley]

But yeah, so. And at the moment, listen, they use this technology and they use it to just extend shelf life. So you can still refrigerate the bell pepper and then this just makes it last a little bit longer. The same way that salad greens still go in the refrigerator, but the bag makes them last longer. But the thinking is in parts of the world where you don't have a refrigerator or for fruits and vegetables that don't work in the refrigerator, if you could spray this on them and keep them fresh for longer that way.

[Latif Nasser]

Yeah.

[Nicola Twilley]

I mean, it's.

[Latif Nasser]

And you think this could scale.

[Nicola Twilley]

Oh, yeah, yeah. You have to figure out for every single different fruit or vegetable, what's the.

[Latif Nasser]

Right breathing production line to do that?

[Nicola Twilley]

They're in commercial scale production. And here's the interesting thing of convincing people that this is a good idea. You know, people a hundred years ago thought refrigerated food was dangerous and immoral.

[Latif Nasser]

And now we're the opposite.

[Nicola Twilley]

Right now we're the opposite. I mean, there's technology as well that's enabling that same. Different technology, but same idea for meat.

[Latif Nasser]

Whoa. Seriously?

[Nicola Twilley]

One of the consultants I spoke to was like, listen, we might get to a stage where we're shipping meat around the world with this technology. It's not refrigerated, but then it's sold out of the chill cabinet at the supermarket. So you don't freak out, basically, because, I mean, for example, that's what happens with soy milk. Soy milk doesn't need to be refrigerated. It just is because people think that milk should be cold. But the idea of buying non refrigerated meat, I mean, I don't even. My.

[Latif Nasser]

That would be dicey. That feels dicey. But you think that's possible? There are people doing that. There are people working on that.

[Nicola Twilley]

They have product. Like it's. It's about scaling it up. I mean, they're further behind and they're also introducing their product first into restaurants because consumers are Freaked out. But restaurants, right?

[Latif Nasser]

You know, restaurants are like, we'll try it. It'll cut our bottom line.

[Nicola Twilley]

Exactly.

[Latif Nasser]

It does. It did give me the. Just as you were describing it, it did give me a little bit of the creeps. Like just feels weird. Like you're like, that should be rotting, but it's not rotting.

[Nicola Twilley]

But that's what we all thought about refrigerated food.

[Latif Nasser]

I know, it's so funny. It's so funny how quickly that becomes natural.

[Nicola Twilley]

Totally.

[Latif Nasser]

So that was my conversation with Nicola Twilley, whose insights I always find to be non perishable. Her book is called How Refrigeration Changed Our Food, Our Planet and Ourselves. Thank you to Nicola for coming on. And if you want to hear more from her besides the book, you can also check out her podcast called Gastropod. A big thank you to Jim Lugg and Jeff Wooster, who we also talked to about lettuce bags. This episode was reported by, let's be honest, it was reported by Nicola Twilley, but also Maria Paz Gutierrez and myself did a little bit of reporting. It was produced by Maria Paz Gutierrez, fact checking by Emily Krieger, and edited by Alex Neeson. Okay, one last tiny thing. I swear, we often at the end of the episode, we say the name of the whole staff of the show because we are proud of the people we work with, but the people we don't mention is there is a whole station who works with us here at wnyc and one of those people who works at the station who was integral to getting this show out from week to week, he is leaving the station, Steven Gangnaram. He is one of the most skilled and consistently competent people any of us has ever worked with. He was responsible for it and fixing our computers all the time, which happened. I mean, I can't even count. So anyway, thank you so much, Steven. We really appreciate you and we'll miss you. I will catch you in if it's an apple a day, I will catch you back here in seven apples. In the meantime, stay crunchy, stay crispy, stay healthy.

[Nicola Twilley]

Hey, I'm Lemon and I'm from Richmond, Indiana. And here are the staff credits. Radiolab was created by Jad Abumrad and is edited by Soren Wheeler. Lulu Miller and Latif Nasser are our co hosts. Dylan Keefe is our director of sound design. Our staff includes Simon Adler, Jeremy Bloom, Becca Bressler, W. Harry Fortuna, David Gable, Maria Paz Gutierrez, Sindhu Nyanan Sambanda, Matt Kielty, Annie McEwen, Alex Neeson, Sara Khari Sarah Sandbach, Anisa Vitza, Arianne Wack, Pat Walters, and Molly Webster. Our fact checkers are Diane Kelly, Emily Krieger, and Natalie Middleton.

[Latif Nasser]

Hi, my name is Tresa.

[Nicola Twilley]

I'm calling from Colchester in Essex, uk. Leadership support for Radiolab's science programming is provided by the Gordon and Betty Moore Foundation Science Sandbox, Siemanns Foundation Initiative and the John Templeton Foundation. Foundational support for Radiolab was provided by the Alfred P. Sloan Foundation. If it's time for you to say goodbye to your car, truck, boat, motorcycle or rv, consider donating it to wnyc. We'll turn the proceeds from the sale of your vehicle or watercraft into the in depth news and programming that keeps our community informed. Donating is easy, the pickup is free, and you'll get a tax deduction. Learn [e-mail] car.

[Latif Nasser]

This is Ira Flato, host of Science Friday. For over 30 years, the science Friday team has been reporting high quality science and technology news, making science fun for curious people by covering everything from the outer reaches of space to the rapidly changing world of AI to the tiniest microbes in our bodies. Audiences trust our show because they know we're driven by a mission to inform and serve listeners first and foremost with important news they won't get anywhere else. And our sponsors benefit from that halo effect. For more information on becoming a sponsor, visit sponsorship.wnyc.org.