Science Friday - Thanksgiving Food Science, Force of Infection, Food Inequality. Nov 19, 2021, Part 2

Episode Date: November 19, 2021

Blunting The Force Of Disease Is Complicated  COVID-19 vaccines are highly effective at preventing severe disease. But their efficacy in lab-controlled trials may not exactly correlate to how well they work in the real world. David Kaslow, chief scientific officer at the global public health nonprofit PATH, explains that a factor known as the “force of infection” plays a role in determining how well vaccines work. The force of infection describes the attack rate of a pathogen—the amount of time it takes a susceptible individual to get infected in a given population.  In a study recently published in the academic journal NPJ Vaccines, Kaslow and his colleagues found that in vaccine trials for rotavirus and malaria in Africa, efficacy could vary widely between two trial sites. When there were many infections in the community, the overall efficacy of the vaccines appeared lower than in communities where disease incidence was low.  While the same sort of studies haven’t yet been done on the coronavirus outbreak, Kaslow argues that similar factors may be at play now—pointing to a continued need for non-pharmaceutical measures to control transmission, from masking to social distancing.       The Chemistry Of The Perfect Cookie With several major food-related holidays on the horizon, we’ve got a challenge for you—checking your cookie chemistry. Each batch of cookies you make has the potential to be a mini-science experiment, with the specific ingredients you use, the ratios between them, and cooking times and temperatures all variables in the mix.  Jennifer Powers, a science educator at the Oregon Museum of Science and Industry, discusses the role of types of sugar in transforming your cookie’s texture from chewy to crispy. She encourages listeners to take on her educational resource—the Cookie Chemistry Challenge—to engineer the best batch of cookies possible.       Food Failures: Add A Dash Of Science To Your Thanksgiving Recipes This Thanksgiving, put your cooking skills to the test. Looking for tips to avoid singed sweet potatoes, acrid apple pies, and a burned bird? In this archival segment from November 18, 2016, Molly Birnbaum and Dan Souza from Cook’s Science help us understand the science behind favorite Thanksgiving recipes so you can avoid food failures, and get the most out of your roast and side dishes.      America Has A Food Disparity Problem As of 2016, more than half of American children had a diet that standard nutritional recommendations would consider “poor quality.” And there are stark differences between children in wealthier and poorer households. Poor nutrition can have lifelong impacts on health, including Type 2 diabetes, heart problems, and dental cavities. But it isn’t always clear what families need to provide healthier foods for their children. One popular explanation, now debunked, was the theory of food deserts: Poorer neighborhoods just don’t have grocery stores, and families must buy their food from convenience stores and gas stations. But if more grocery stores aren’t the solution, what is?  Sociologist Priya Fielding-Singh explores these questions in a new book, How The Other Half Eats: The Untold Story of Food and Inequality in America. Her research, the product of months of immersive time spent with families in their kitchens and as they navigated grocery stores with kids in tow, describes an alternative explanation for the socioeconomic disparity between kids’ diets. Fielding-Singh explains healthy food takes emotional and energy resources that lower-income parents must often spend in other ways.  Guest host Roxanne Khamsi talks to Fielding-Singh about her research on family food choices, and the kinds of changes that might allow children from all backgrounds to enjoy healthier foods. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Roxanne Camsey. Ira Flito is off this week. Later in the hour, some food for thought as the U.S. heads towards Thanksgiving. But first, there's been a lot of attention given to the numbers around vaccine efficacy, and they are impressive. But how well do the numbers they come up with in a careful clinical trial match the numbers in real-world conditions? A vaccine's real-world performance may be tied to something called the force of infection, which is related to how long it takes for a susceptible person to get sick in a population. Joining me now to talk about that is David Caslow, Chief Scientific Officer for Path, a global public health nonprofit. He wrote about this recently in the journal Nature. Welcome.

It's great to be here, Roxanne. So David, can you start us off by just helping us understand what's the basic definition here of force of infection? So force of infection, kind of the technical definition is the rate at which susceptible individuals in a population acquire an infectious disease in that population over a period of time. Think of it as the attack rate or the incidence rate, how many people are being infected over a certain period of time. When this pandemic all started, we heard a lot about something called R-Not. How is this different? They're related to one another. So R-not is a measure of the transmissibility. of a particular pathogen, in this case the SARS-Co-V-2 virus. So how many people does a single infected person pass that infection onto?

That's the R-NOT. The force of infection is the other side of the equation, which is how many people does a susceptible individual need to contact before they become infected? So different side of the equation, one is goose transmitting it, the other one is who's getting infected. It's really interesting. So if there's more virus around me, because now the force of infection is centered around the susceptible person, so if there's more virus around me, I've got a bigger chance of

getting infected and getting sicker. That's right. And so that's called the infectious dose. So how many viruses do you need to be exposed to before you get infected? And does that dose determine how severe disease you have? And there's some evidence to suggest that that infectious dose, kind of the level, the exposure level, does have an influence on how severe the disease you get once you become infected. It sounds like with force of infection, the infectious dose matters a lot. But why is that? In short, infectious dose matters because it determines in part whether or not an infection can take hold,

determines in part how severe the disease will be, and it determines in part how well the vaccine will protect you, particularly against infection and mild, moderate disease. The viral dose we get matters even if we're vaccinated? It does, Roxanne, and the reason for that is it's a numbers game. So let's say you have a thousand viruses that you're exposed to. Your immune system at that time has only a certain capacity. So let's say you've got a thousand viruses you're exposed to. You've got one or two tanks to fire on those.

If the infectious dose is higher than a thousand, you can overwhelm your defense system. You can overwhelm your tanks and the virus can take hold. So the lower that we can keep that exposure to the virus, the better chance your immune system, those tanks and those planes have to block the virus from getting through. And is the idea that that infectious dose isn't the same everywhere we go? Like, is it variable? It is variable. And that's what's really described in that paper that you referenced. And what's been observed is that vaccine efficacy varies depending on kind of where you are. I mean, that gives us a clue as to force of infection as a determinant of what your risk of infection is. So in these vaccine trials, there are measures in place to mitigate the spread of the coronavirus.

Are they kind of too idealized? Like, how does this apply to what we know from vaccine trials and the real world? And that's one of the problems, but also one of the strengths of a phase three trial. They're very well controlled. So you try to use the utmost standard of care in the case of, you know, SARS-CoV-2, making sure that people are. physical distancing, you know, wearing a mask, good hand hygiene, et cetera, et cetera. So you're measuring the vaccine efficacy or how well the vaccine works in an ideal situation. The problem is that may not reflect what's going on in the real world. And what was observed in this and published

in this paper is that when you look at different forces of infection, you see a difference in vaccine efficacy. So the highest efficacy was observed in the places where there were the lowest cases of that disease in one case, malaria, the other case rotovirus in those settings. And the lowest vaccine efficacy was seen in the settings where there was the highest rates of infection in the control group. So you studied this force of infection phenomenon using malaria as one of the examples. Based on what you saw, does it mean that even community to community, you'll see different performance and vaccine efficacy in the real world? Exactly right, Roxanne. So what was observed in that malaria trial? It was a face brief trial,

run an 11 research centers in seven different African countries. And what we saw was just under 45% efficacy in one setting. And in another setting, we saw over 80%. And so what was observed as was the highest efficacy of 80% was seen in the setting with the lowest attack rate. In that case, it was three cases per 100 children. And we saw the lowest efficacy, just under 44% when the attack rate was 300 cases per 100 children. And have we seen this play out with the COVID vaccines as well? Don't know that we have really good data to be able to do the type of comparison that was done in this phase three trial of malaria. It was a. single trial over 11 different research centers. So that data has not been observed in the same way

with SARS-CoV-2, but I think there's some evidence to suggest that vaccine efficacy could vary depending on the force of infection. So what's the take-home lesson for the public here? This isn't just something of interest as disease modelers, right? Like, does this matter for the everyday person? This whole concept of force of infection? I think this force of infection does matter. And the reason why it does matter is, and it's widely known that the vaccine efficacy may wane over time. Part of the reason why it may wane over time is your immune system starts to decay a bit, but it could also be because we have different variants of concern, which have a higher force of infection. And so how can we mitigate that higher force of infection? We can go back to some of the public

health and social measures that we used previously to try to reduce the force of infection, which should improve the vaccine efficacy. Wow. Well, this is definitely something I'll be thinking about as we head into the holidays and we're exposed to potentially new social situations and things like that. But this is super fascinating. Thank you so much. Thanks, Roxanne. David Caslow is Chief Science Officer for the Global Public Health Nonprofit Path. Here's a quick challenge for you with some serious food holiday.

approaching, check your cookie chemistry. Because, you know, sometimes your cookies, while tasty, just aren't crispy enough for your discerning cousin, or aren't chewy enough for your favorite aunt. So how do you engineer the perfect cookie? Jennifer Powers is a science educator at the Oregon Museum of Science and Industry, Omsey, in Portland, Oregon. And she wrote an education resource for us on this topic. Hi, Jennifer. Hi, thanks for having me. If you look at it, a cookie as a science experiment, there are a ton of variables in there. But we're going to talk about just one, sugar. What's the importance there, you know, like besides sweetness? Yeah, there's actually a lot of science that goes into the different types of sugars. And the type of sugar that you

choose to put in your cookie dough, it's significantly going to change how that cookie turns out. So maybe you want a crispy cookie or maybe you want a chewy. cookie. And the type of sugar that you choose is going to determine the crispiness or the chewiness, or at least partially determine the crispiness or the chewiness of your resulting cookie. And one can't really engineer a half chewy, half crispy cookie. You kind of have to go all in, right? Yeah. You know, you can always do a balance, right? And that's the fun of this activity, is it's really about digging in and finding the cookie that works for you and trying things out until you get there. And who doesn't love making a ton of batches of cookies in order to find the best

cookie for you, right? You got to find the crowd pleaser. Exactly. So if you play with the type of sugar in the mix, what effect does that have on the final cookie? Like, what's the magic in the sugar? So the key to sugar actually has a lot to do with the moisture in your cookie dough. So if you're going with all white sugar, White sugar is almost 100% sucrose. But if you go with a mixture of white and brown sugar, brown sugar contains more fructose and glucose. And the size of the molecules there are going to hold on to different amounts of moisture in your cookie dough. So sucrose is a bigger molecule. And it's just not able to hold on to as much moisture. So if you're looking for a crispy cookie, using more white sugar is going to dry out your dough a little bit more, and you're going to get

crispy or cookies. But if you add in some brown sugar or completely go all in, do all brown sugar, you're going to have more fructose and glucose molecules. They're smaller. They're going to hold on to more moisture, and you're actually going to end up with a chewier and more moist cookie. So you're describing a really cool tweak that we can make with the sugar we use in order to change the chewiness and crispiness of the cookie. Is that effect different from the one we would get just by baking the cookies a little less? You know, that's the fun about experimenting with the chemistry of cookies, right? Because we're talking about moisture levels here, right? Not really about sugar. Sugar is a way to change the moisture level in your cookie. And you're right. If you leave

the chewiest, most brown sugar concentrated cookie dough in the oven for, too long, you're still going to end up with a crispy cookie. So it's a balance, right? It's a balance of finding the right temperature to bake your cookie at, the right amount of time, and the right sugar and other ingredients in order to come out with just the perfect cookie for you. So here's our challenge. Try this at home. Engineer the perfect cookie. Jennifer Powers is a science educator at the Oregon Museum of Science and Industry in Portland. Oregon. If you want to dive deeper into kitchen chemistry, you can find her resource on our website at Sciencefriday.com slash holiday science. When we come back, food science continues.

Adding a dash of science to your Thanksgiving meal, we'll talk turkey after this. Hey there, podcast listeners. Last week, I shared that we're celebrating our 30th anniversary, and I asked you to make a donation. I know I've mentioned. I've mentioned. in this before, but it bears repeating. Donations are crucial to Science Friday success. And right now we have a dollar-for-dollar match in effect, which means that any amount you give will be doubled. Yes, doubled. So please go to ScienceFriety.com slash support to make a donation. Again, that's sciencefriiday.com slash support. And thanks. This is Science Friday, and I'm Roxanne Camsey. If you have taken a trip to the grocery store lately, you know that Thanksgiving is under a week away.

They've got piles of turkeys, mountains of sweet potatoes, they're stocking up on pumpkin spice. They've got everything. So we're opening up the SciFri archives and dialing all the way back to 2016 as Ira tries to add a dash of science to your Thanksgiving meal. We've all been there. You've roasted a perfectly golden brown turkey. You've basted it for hours. cooked it low and slow and resisted opening that door every five minutes. When you finally carve it up and take that first taste, you get that sad, stringy bite.

The one that makes it reach for the gravy, right? A glass of water. Well, we're here to help you this holiday to become a master of your roast. And I'm not just talking about the turkey. We're going to tackle side dishes, too, the unsung heroes of any Thanksgiving meal. What can you do to balance the sweetness on your sweet potatoes? which apples are best for baking. How can you create a broiler map?

Yeah, we all need this to tell you the hot spots in your oven. My next guests are here to add a dash of science to our recipes. Molly Bernbaum and Dan Sousa are co-editors of the new book, Cook Science, How to Unlock Flavor in 50 of our favorite ingredients from America's Test Kitchen. They join me here in our CUNY studios. Welcome to Science Friday. Thanks for having us. How common is that kind of mistake with the turrets?

I think a lot of people have a difficult time with turkey. I mean, for one thing, people really cook it pretty much once a year. So you don't kind of learn the mistakes and then apply those next year. So you've got to start with a really good recipe to get good results. So is that the first biggest mistake? Get a good recipe? Yeah. Start with a well-tested recipe, I think, is key.

And if you try it one year and you make a little change, make note of it, and then kind of follow through on that next year. But Turkey itself poses some challenges in that it's really an odd thing. to roast in terms of its shape and in terms of the composition of its muscle. So if you look at the breast, which is primarily white meat, those muscles are made for flight, which turkeys don't do very much, but they're kind of fast-twitch muscles. They're very lean and they can dry out really quickly. Then the legs, which do a lot more work, have a lot more connective tissue, more myoglobin, more oxygen goes there, and those need more heat to break down. So you're trying to roast two things

at once and have them both be done perfectly. It's kind of an odd challenge. And a helpful solution is what? How to do that? We have a few helpful solutions for that. One of the most easy things to do is actually break down the turkey a little bit so that you roast the breast separately from the legs. You can roast them all in the same pan, but if you separate them, they end up finishing right around the same time when the breast reaches 165 or so, and the legs reach 175 or so degrees Fahrenheit. And just having them separately because the breast is so much bigger, it cooks a little bit slower. Now, one of the real problems I've found over the years is finding the actual temperature of the oven. Yes.

You know, my ovens are off of 25, 50 degrees sometimes. So that thermometer is really important to go in. If it says roast to it for X number hours at 350, you better know that your oven is only 325, right? 100%. Yeah. Ovens go out of calibration really easily. And when was the last time you calibrated your oven? Oh.

Right? Yeah. I think most people. I don't even know how to do that. Right. How do that? It depends on the oven. You know, in the owner's manual, which I'm sure you still have.

Of course. We would tell you that. But, you know, we find that an oven thermometer that you put in there is really important. So you want a nice new one in there. And, you know, you can adjust your oven based on what the reading you're getting out of it. And that's an easy way to kind of make it work. And then you can have a professional calibrated as well. But they can vary a ton.

They're not the most accurate instrument in the kitchen. But another thermometer that's really important is a digital instant read thermometer. And that's for taking the temperature of the bird itself, when it's close to done. And that's super important because you really can't judge it any other way. And you're going to mess it up if you don't know. You want to pull it at 160, 165 in the white meat. That's the safe temperature.

Anything over that, you're not doing it any favors. And, you know, when you cook in the oven, you've, the oven is full. It is really chocked full of stuff with the side dishes. But yet it's uneven temperature in different places. How do you know where it's hot and where it's cold? Can you do something? So one thing is most turkeys can. can rest for a really long time after they come out of the oven.

So it's really nice to get your turkey done and let it rest up to an hour even. It's so big, huge thermal mass. It'll stay warm for a long time. Freeze up your oven to do a lot of other stuff. But if you're using your broiler, which is great for finishing the top of casseroles on Thanksgiving, and it's the fastest cooking method you can do in the oven. We came up with a really cool technique. We call it a broiler map.

So on a rimmed baking sheet, you line it with white bread, and you put it the distance from the broiler that you're going to put your food, and you turn the broiler on and you let it go until, some part of the bread is basically burnt. Take it out and you'd be amazed at how uneven it is. But you really get to see what parts get hot, what parts are cool. So when you're broiling something, you can adjust and put the food in just the right place. We asked our Twitter audience for some questions in advance. We've got a couple here. Linden asked, is it really worthwhile to bring the meat up to room temperature before cooking? No, it's not totally necessary to bring the turkey up to room

temperature before cooking. I think the most important thing is the temperature at which you take it out of the oven. So getting that breast meat to around 160, 16, and getting the legs to 170, 175. It might take just a little bit longer if the turkey is colder when you put it in, but other than that, it doesn't really matter. Our own Jen Kwok asks, does Basing really do anything that seems to just drip off? It does do something, but it's not really what you want it to do. So what Basing does is you put a hot liquid on the outside of it and you actually get evaporative cooling. It evaporates off. just like water on our skin on a hot day, and it cools the surface down. So it'll actually slow down the speed of cooking, of your turkey,

which is not really something you want necessarily. It also adds liquid to the exterior, and what you're trying to do is drive moisture out of the skin so that it can then crisp and brown. So you don't need a base. It's kind of a waste of time. That's kind of a waste of time. Okay, that's good answer.

You have plenty of other things to do on Thanksgiving. No bother basing. Let's got a Niko in San Francisco. Hi, welcome to Science Friday. Thank you for taking my call. My question is about brining. I know brining all meats tend to make it more tender, but it's so counterintuitive.

You'd think sodium would actually make it drier. How does brining actually work? It seemed like salt would pull the moisture out of the meat. Right, right. And sometimes it does. So if you want to dry salt your turkey, what happens first is the salt pulls the moisture out, but then it forms a concentrated brine,

and then the salt starts to move into the turkey through diffusion. That's what happens in a brine as well, a water salt mixture. And as the salt moves into the turkey, it actually changes some of the proteins in there, helping them to hold on to water more easily so that when you cook it, it maintains more moisture. And it also seasons the turkey throughout as the salt moves in throughout the whole turkey. It's also really important the percentage of your brine. So we use one in a test kitchen that's usually between six and nine percent. If you go too high, you are just drawing moisture out. There's enough dissolved solids inside. of muscle fibers that the water through osmotic pressure still wants to go in, but if it gets

too high, it's going to pull it out. So what cup per water is that, six to nine percent? Oh, you're quizzing me. I'm off the top of my head. I got to look it up in the book. Look it up. This is Science Friday. I'm Ira Flato, Molly Burnbaum and Dan Sousa are walking us through a few tips. Let's go to the green part. I'm going to try to sneak in some healthy stuff into the meal. You can make a kale salad. It's not your typical side dish, but I I'm learning now that you massage your kale, Molly. Is that what you do with kale? You massage it? That is definitely something you can do with your kale. So kale has two issues that I think make it hard to love it raw in a salad. One is that it's kind of tough, and the second that it can be very bitter. And to help with the toughness of kale, massaging it, actually running your fingers over it to help the leaves loosen up a little bit.

You can use a rolling pin over a bag. It really helps tenderize the leaves. But what happens when you do that is it makes the flavor of kale a little bit more bitter. And that's because the flavor of kale really only happens when you start to damage the cells within it. Because then an enzyme interacts with a sulfur-containing compound to create a totally new compound. They wouldn't interact if the cells weren't damaged. But this new compound is very bitter. I see you've got a bag. Is that a bag of kale?

I do have a bag of kale. We brought you kale. We have two samples of kale here. One, we worked really hard on figuring out how to get kale to taste less bitter. Right. All right. I've got one sample here. You have one sample there. That is raw kale that has just been lightly torn up for a salad. Mm-hmm. And this might not, neither of them might be super pleasant because there's no dressing or anything, but that is just kale that's been washed and torn up. Taste okay. Taste okay. Taste green.

Exactly. It tastes healthy. Okay. Now, this one. This one is massage. Massaged kale. Massaged kale. And so what we did is... Wow, it is much more bitter. Mm-hmm.

Mm. We need dressing. Dressing. Yeah, I mean, sometimes adding a lot of dressing to very bitter kale can help. And so one thing we did in the book was trying to figure out how to make kale less bitter. And we discovered that rinsing it after you massage it and create all this bitter flavor can lessen the bitterness of the kale. Well, this happened to other vegetables that you've... You know, maybe broccoli or anything like that, too?

Well, it's interesting. That's the same effect? It's interesting. There's a number of different vegetables that kind of go through this. So in the Braska family, which kale is and cabbage, they really don't have flavor until you damage the cell. So you can control that. The same thing is true with alliums. So your onions, garlic, shallots, the more you cut those, the more intense the flavor is going to be.

You know, even how you slice an onion, whether you slice it pole to pole or the opposite direction can actually change the amount of flavor. So there's a lot of vegetables that kind of fall into that camp. Another favorite is a green bean casserole. I love that. It's sort of gooped up with mushroom soup. Everybody uses mushroom soup in something. Of course. You say try roasting the green beans.

Why is that good for bringing out the flavor? Well, green beans are interesting in that they're a very hearty vegetable, and that's because most of their texture comes from the fact that we're eating the pod and not the immature seeds within them. And because of this, you can roast. them for a long time and actually keep the texture and keep them together so that they stay intact. And this is because they have a lot of cellulose and pectin in this pod. So roasting them for a longer time or brazing them allows them to soak up the flavor of the brazing liquid in a really nice way.

So you can let them in the oven for a long time still get really good flavor. Let's go to the phones to Rachel in Pittsburgh. Hi, Rachel. Hi. Go ahead. You're on. Well, thanks for taking my call. I'm looking forward to bringing a side dish to my boyfriend Thanksgiving, and I was really wanting to make the kind of quintessential sweet potato, marshmallow, nut sort of casserole, but it always ends up tasting more like a dessert instead of a side. So I was wondering if you all had any suggestions about making it a little less sweet. Well, that's a tricky one. When you put marshmallows on it, you're almost kind of asking for that dessert aspect to it.

But, I mean, the one thing that's really interesting about sweet potatoes is that they kind of change. From when you pick them, they're relatively high in starch and low in sugar. And then during storage, there's an enzyme called amylase that converts some of that starch to sugar. So they get sweeter during storage and then a little bit sweeter during cooking. So longer, slower cooking can increase their sweetness a little bit. So I would recommend that you want to cook them actually relatively quickly. So if you're going to make them mashed first and then put them in the casserole, you know, put them into the water, bring them right up and boil them and get them done that way as opposed to, you know, slow roasting or anything like that. And then I would have to say, leaving up the marshmallows will probably help you it a lot.

It's not really a potato, is it, a sweet potato? Is it a real potato? Yeah. Yeah, it's in the potato family. But, yeah, it is quite different than white potatoes. And it's not the same as yams. Those are often names that are lumped together, but sweet potatoes and yams are totally different. One is more starchy than the other?

Yes. And yams are enormous. They're like the size of a small car. That's an exaggeration, but they're much, much bigger than sweet potatoes. I see if I can get a lot of it. I'm going to keep that vision. Let's go to Val in Sacramento. Hi, Val.

Hey, so my question is I have a whole bunch of apples that are, that besides making apple juice and apple pot, I have no idea what to do with them. and for the holiday, I was wondering, how could I incorporate those apples into side dishes or other food besides apple pie and apple juice? I love my apple pie, though. Yeah, what else can you do with apples besides? You know, you go apple picking, you're coming home with a bushel. You are. You're coming home with a lot. Well, so it really depends on what the kind of apples that you pick, actually.

So we did a really interesting test in the book where we figured out we baked a huge variety of apples, and we also cook them suede in little bags at 185 degrees, which is the temperature at which pectin breaks down very rapidly. And we saw a huge difference between like the red delicious, golden delicious apples, which turned them mush very, very fast and are great for something like applesauce. And Granny Smiths, Pink Ladies, and Honeycrisp, which are on the other end, which stay firm for a long time. So those are great for baking.

You can bake them whole. You can kind of core them out and use some of that apple chopped up with other more savory flavor stuffed back in. Those make a really nice baked apple. We also have in the book a really nice French apple tart, which is a little bit different than an apple pie. It uses golden delicious and they're nice and soft. There's a mash underneath and then some softened ones on top. And that's a little more elegant, I think, than an American apple pie. It's a beautiful tart. This tart, they're shaped in a rosette on top, and it's actually quite easy to make. Top talpum, as they say. Exactly.

In France. We'll leave the pronunciations to you on that. I love that one in those of hours. Let's go to Cleveland, Ohio. Hi, welcome to Science Friday. My question is regarding the myard reaction, how does that actually improve the flavor of your food? And then kind of along the same lines with brining your food, if you put like sugar or honey or maple syrup,

does that actually impart the flavor since those molecules are so much bigger than salt or are you wasting good maple syrup? these are there are both really good questions so um for the my ard one what's what's kind of happening during that reaction is you have amino acids reacting with reducing sugars which are really small sugars and it improves the flavor because it creates hundreds of new flavor compounds there's a there's a few reactions that go on during it and you get creation of compounds and then destruction and creation even more and you end up with something that is really really complex if you

compare that to something like caramelization which is just sugar um it's it's it's infinitely more interesting flavor. So that's what's going on with the myriad reaction. In terms of brining sugar, yes, sugar will move a bit into the meat. It has a little bit of the same effect of salt in terms of pulling moisture out. So we do include sugar in a fair number of our brines. You have to be careful if you're doing something that you're going to roast at a relatively high temperature because you can get additional browning, whether you want it or not, if you add sugar. We like it on pork a lot because that sweetness works really well with it. Let's talk about leftovers. because we're going to have a few.

You know, everything seems to taste better, doesn't it? A lot of stuff, does it? A lot of stuff. Is that in our mind, or is there really something going on in the chemistry of what's going on in the dish? There really is something going on with it. And I actually don't know a ton about the chemistry behind it. Sometimes you can get these kind of warmed over flavors that aren't very pleasant,

but things like stews, a lot of times the flavors just get a lot more complex. in terms of like flavor movement going into things, I think that I think it's a good method for like a lot of stews and soups and those like that. If you want some great methods, I suggest you get a copy of Cook Science, how to unlock flavor and 50 of our favorite ingredients from America's Test Kitchen. You can read an excerpt of the book about the best baking apples. Yeah, a lot of different apples in there. Jonathan's were my favorite.

It's on our website at ScienceFriiday.com slash Thanksgiving. Molly Bernbaum and Dan Sousa co-editors of Cook Science. Thank you for coming back. Thanks so much for having us. Yeah, thank you. Nice to have you. That discussion was from 2016, and we hope those tips make your holiday table a bit more tasty.

After the break, a new book on the social factors that make feeding kids healthy food harder for poorer families. How the Other Half Eats. After this short break. This is Science Friday, and I'm Roxanne Camsey. being a parent requires a thousand different choices. Each of them can feel like a chance to mess up something important and fragile about your child forever. And as if you don't have enough on your plate already, many of those choices are about what to feed your growing child. Now, add the fact that some kids are fussy eaters and they're exposed to an onslaught of ads telling them to ditch that broccoli for a delicious bag of Doritos.

even harder, right? For many, a tight household budget requires wearing every food purchase against other things they could be paying for instead, a tank of gas, their electric bill, or a very small treat like a fancy coffee. Now you might have some sense of what it's like to be Naya, a single mom of three whose grocery habits and choices are part of the story my next guest is here to tell. Naya, like many parents, knows exactly what foods are healthy for her kids. But the realities of her life and her fixed income make it challenging for her to keep her kids away from junk food. Here to explain more is Dr. Priya Fielding Singh, a sociologist at the University of Utah, and an author of a new book about the tough choices parents must make that affect their

children's diets, how the other half eats, the untold story of food and inequality in America. Welcome, Priya. Thanks so much for having me. So what was the moment when you decided to to study the problem of food inequities in America? Yeah, so I have long been interested in issues of inequality. I knew that I wanted to study what I saw as a really intimate form of inequality. Food, diet, the stuff we put in our bodies every day, which I see both as a product of inequality in America, but also as a driver of inequality, in particular disparities in diet-related health outcomes.

What I found really interesting in your book was that from 2002 to 2012, the percentage of people in the U.S. with an unhealthy diet actually decreased from 56 to 46 percent, but that the decrease hides some inequities. Can you say a bit more about that? That's right. So if you look kind of in the aggregate, average American diet, first of all, there have been nutritional gains. But those gains have not been shared equally by members across American society. And what we've seen is that while higher income individuals are now consuming a healthier diet than they were 20 years ago, lower income individuals' diets have stagnated and at times declined. There are similar trajectories for comparing white Americans who are eating better than ever compared to black and Mexican Americans who have not. seen the same gains in their diets. And so this really is a story of racial and socioeconomic

inequality and a gap that if nothing else is holding steady and looks to even be growing. So a lot of the diet disparities that we see with adults really hold for children as well. And the other thing that you mentioned in your book that was eye-opening to me was we often talk about food deserts, right? You know, which are these neighborhoods with no grocery stores, they might have a convenience store or a gas station, but no whole foods. And that these food deserts are a source of disparities in what people eat. But then there's something kind of wrong with the concept of food deserts, right? That's right. The thing about the food desert argument is that even though food deserts are real, they exist, and there are really important inequalities in

access to healthy food. You know, we've made some assumptions that have a face validity to them, but then when you really dig into them, they're actually not borne out by the data, and they actually don't make as much sense as it may seem at first glance. So I'll just mention one. There's this assumption that people who live in food deserts, because they don't live near or in walking distance of a supermarket, are forced to shop at gas stations or convenience. convenience stores where there may be limited produce. In reality, 90% of grocery dollars are spent at supermarkets and low-income food desert residents are just as likely as anyone else to drive to a supermarket. In fact, also 90% of supermarket trips are made by car in this country. So in America,

a really car-dominated nation, the vast majority of people actually have actually. to a privately owned vehicle and are quite willing to drive. And in fact, among the families that I met, it was the low-income families that were often most willing to drive to get their groceries because they wanted to go to the stores that had the most affordable food and the best deals. And so what happens when a supermarket opens in a food desert is that people just go from spending their money at further away supermarkets to the closer supermarket. but it doesn't actually change what they're purchasing. So interesting.

So I've become very wrapped up in this way that you're kind of breaking apart the myth in a way of food deserts. And part of what you're talking about is finding these unexpected aspects of how people interact with food. And that you've done that in a large part by using these ethnographic methods. So it wasn't surveys and it wasn't anything that involved a lot of numbers. instead, you spent a lot of time with families. Can you say a little bit more about how you used all of that time to learn about their food choices? Absolutely. So I think we have really great data about the breadth of inequalities that we face,

but we don't have that high quality data that goes in depth about how these inequalities are experienced. So I ended up conducting interviews with about 160 parents and children across class and race. And then from those 160, I knew that I wanted to spend intensive embedded time within some families to really understand how what they were saying squared or not with what they were doing. So I chose four families with whom I had conducted interviews and asked if I could spend some months just with them, within their homes, within their cars, just kind of following them around, seeing how they live their lives. And for me, the focus was on how does food

fit into those lives? What meaning does food take on, given their broader context? You know, you could imagine asking a survey question where you have a multiple choice set of answers, like how healthy the food is, how cheap the food is, how convenient. the food is. But what would that really tell you about how those choices are made and how when the fridge runs empty, priorities shift, how difficult tradeoffs are forced by families' unique circumstances? It's really hard to suss that out with what I think of as as slightly more superficial measures. So, and you mentioned a moment where Naya, the woman I referred to in the introduction, buys a slightly expensive coffee for her daughter. What did that moment teach you when

you observed it? Yeah. So Naya was the lowest income mom that I spent time with. And Naya really lived in many ways hand to mouth, like she was far below the poverty line. And, you know, one afternoon after driving around with Naya, she, her daughter and I drove by a Starbucks. And she, and her daughter looked each other in the eye and they pulled into the parking lot and we went inside and Naya ordered her daughter and her two Frapicinos where the bill came out to about $11. And, you know, this was early on in my observations and I was actually almost stunned by the bill because of just how deep in the whole financially Naya was. And what I learned was that spending that money that way actually made

perfect sense, given her circumstances, given the context of scarcity within which she was raising her daughter, being able to treat her daughter to something delicious and tasty and joyful amidst so much scarcity and hardship was important to Naya, and it was a way that she could emotionally nourish her daughter. This speaks to something that I felt as I was reading the book, which was that you were saying that there's a symbolic value of food. So that in some scenarios like what you were just describing, some parents might get junk food for their kids because it's the one thing they can say yes to. Why have we overlooked this really important element in the discussion about food disparities?

Food's symbolic and emotional meaning to us is something that all of us intuitively know about. Every one of us has experienced the comfort of a dish that reminds us of a certain person or a place or a time in our. lives. All of us at different times eat for comfort. We eat to remember who we are, where we came from, what we believe in. And yet, despite this knowledge all of us have in our gut about the symbolic meanings, that discussion has not made its way into a lot of the research on food. And, you know, I don't know if it is in part because there is such a focus on, you know, people's environments and neighborhoods and these broader structures, which is something that I actually applaud and I think is really important. But what my work is trying to do is to show

how those broader structures make their way into families' psyches and their feelings. You're right that it's one thing for a parent to know that something like cauliflower is a healthy purchase, but that it's another thing entirely for them to want to buy that cauliflower, to choose to spend their money on it, to have the time to know how to cook it, and to have that patience to weather the requests from their kids to get something more sugary or more salty. So when you list it out like that in the book, it becomes a lot easier to understand why a parent who might have financial stress might not have the energy to deal with all the things that cooking a head of cauliflower might require. Exactly. You know, you hear these discussions of like,

It's cheaper and it's quick to cook compared to going out to get something, right? But that completely misses the point of all of the steps, all of the labor that go into preparing meals, all of the emotional work, all of the negotiations with children, even moms who I met who had all the resources in the world, still sometimes struggled to do that. And so then when you chip away at those resources, you just see how it becomes, such an uphill battle that the vast majority of moms are losing. And you say moms, but it can be parents of either gender, will have that desire to say yes to their kids.

I think it can be, but I think in American society, as much as we've made any gains on the gender equality front, moms still remain in the vast majority of families, the primary caregiver and the primary food preparer. And I talk in the book about how, you know, the meaning of food is really tied to what it means in this country to be a good, caring mother. While it's true that kids can ask both mothers and fathers, and they do ask both mothers and fathers for junk food, I really focus on the binds that this creates because of how gender food work in America is.

Another way that you challenge the conversation we have about food in your book is that you say, our definition of healthy isn't always inclusive. For example, you write about kale, which is considered kind of like a star of the health food world, but nobody talks about collard greens. So how did families you interviewed feel about that? So this was something that a lot of mothers of color, whom I interviewed, were well aware of and we're often struggling with. I talk in the book about how our understandings of what healthy foods are, what a healthy body is,

are actually fundamentally shaped by our understandings of race and class. One mother, Janae, who was an upper middle class black mom of three, and Janay spent so much time fighting back against this assumption she felt people made that she fed her kids unhealthy food. that she fed them greasy, fatty soul food. Even though Jeanne loved that food and it was nourishing to her and it reminded her of where she had come from and the recipes she had grown up with.

But Janay felt like in order for her kids to be seen as a Brominal class like they were, she also had to feed them what we understand to be white foods like kale and avocado and almonds and yogurt. For mothers of color, particularly black mothers, they faced an added burden that the foods that were really dear to them, that were really core to their identities, were also deemed by society more broadly as unhealthy and unreasonable to feed children. So there's a lot of challenges to face with making this conversation about food better. We started talking about food deserts and how research actually shows that there's. not a lot of benefit to kids' health if you put more grocery stores in poor neighborhoods. What do you think will make a difference if the problem is so much more nuanced and complicated than that?

I think about approaching this problem from two directions. So the first is what is the minimum standard of living that we think parents should be raising their children in? The low-income moms that I met were living so close to the bone. And I think the fact that there are families in this country where a bag of Cheetos is so symbolically meaningful to their kids, that just tells you everything that you need to know about how dire those economic conditions are that they're living in. And no parents should be raising their child in that context. So I think about what are certain social policies that we can put in place, whether it's

around livable wages or subsidizing housing so that families aren't spending half their income on that. Because my research suggests that having stability and security can actually fundamentally change the meaning that food takes on and make it so that junk food doesn't become a way that parents have to buffer their kids against hardship. But I also think this needs to be paired with addressing issues in the food system, particularly marketing to children. aggressive marketing to children that is often focused on low-income, black and Latinx children. And thinking about places where we can nourish kids, whether it's in schools, whether that involves taking junk food out of schools, investing in school kitchens so that kids have exposure and access to healthy foods every day, whether it's expanding that access so that fewer kids are

going hungry. I actually think some of the most exciting places we can start are with kids themselves. Thank you so much for joining me today, Priya. Thank you so much for having me. Dr. Priya Fielding Singh is a sociologist at the University of Utah and author of How the Other Halfeats, the untold story of food and inequality in America. You can read an excerpt of her book on our website, ScienceFriday.com slash food health. If you missed any part of this program or would like to hear it again, subscribe to our podcasts, or ask your smart speaker to play Science Friday. And if you want to contribute your voice to upcoming shows, go get the Science Friday Vox Pop app. We're currently fielding your questions about COVID-19, consumer safety, and more.

That's on the Science Friday Box Pop app wherever you get your apps. Say hi to us on social media, or email us. The address is SciFri at ScienceFri.com. Have a great weekend. IRA will be back Next week, I'm Roxanne Camsey.