On March 27th, 2018 we learned about

Reshaping sugar crystals to reduce quantities while staying sweet

The average piece of milk chocolate is 60 percent sugar by weight. While your stomach and pancreas will need to process all those calories, there’s a chance that the bundles of sugar-sensitive cells on your tongue won’t actually taste it all. This has presented a bit of an opportunity for food scientists looking for ways to reduce the amount of sugar used in sweet foods, as they realized that less sugar can be used if more of that sugar will actually be tasted when you eat. So rather than add sugar substitutes like aspartame, researchers at Nestlé and startup DouxMatok have been trying to reshape the sugar itself so that it’s essentially easier to enjoy, even in smaller doses.

Creating more contact with our taste buds

Nestlé’s approach has been to make what they’re calling “structured sugar.” Using a process that involves spraying sugar, milk and water in warm air, they’re creating porous sugar crystals that dissolve faster than more cubic crystals. This allows more of the key molecules in the sugar to quickly trigger your taste buds, giving you the equivalent experience of eating a sweeter food. By maximizing how much you experience each gram of sugar, Nestle says they’ll be able to cut just how much sugar goes into their recipes by as much as 30 percent, starting with their new Milkybar Wowsomes in the United Kingdom.

DouxMatok’s patented sugar operates on a similar principle. Instead of increasing your tongue’s contact with sugar crystals by making them hollow and porous, their process increases the available surface area of sugar crystals by attaching them to a carrier agent that will help them come in contact with the correct tongue cells. Again, this allows for your tongue to come in contact with more of each gram of sugar, allowing less to be used in a recipe overall.

Selling the public on smaller sizes

Even if both high-surface area sugars keep treats sweet, candy makers are concerned with the dimensions of their product on a larger scale as well. Going back to our original piece of milk chocolate, a 30 percent reduction in sugar will likely result in a noticeable decrease in the candy’s net weight. There’s concern that this may look bad to consumers, and that some new filler agent will be needed to make up the difference.

One option may be just to reshape the chocolate itself. When people were asked to let chocolate pieces melt in their mouths, manufacturers found that spheres were considered the tastiest shape. It’s suspected that a round shape allows air to circulate through the mouth, which makes it easier to smell the compounds that help give chocolate its flavor (aside from all that sugar, of course.)

Source: Designer sugar is here – but just what are we sacrificing for healthier sweets? by Jodi Helmer, The Guardian

On March 11th, 2018 we learned about

Chewing gum stays off the streets when its polymers are recycled into other plastic products

The average piece of chewing gum is tasty for less than six minutes. You might gnaw longer on the flavorless gum a bit longer, but once you toss it out, the synthetic rubber in that gum will keep it from completely biodegrading for hundreds years. When you add in the fact that cities often spend nearly 70 million dollars per year to clean used gum off of sidewalks and streets, and a few moments of tasty chewing starts to look like a major investment, at least for the community at large. Anna Bullus, a designer from England, has some ideas on how to make a dent in the impact of your chewing and bubble-blowing, which is to start recycling it into products you’ll want to keep instead of sticking on the bottom of your chair.

The fleeting flavor of chewing gum is thanks to ingredients like corn syrup or beet juice, but the component that makes it so durable in our mouths (and on our sidewalks) is polyisobutylene. It’s derived from petroleum, and is most often used for its ability to be air-tight and stretchy at the same time. As such, it turns up in gas masks, air bladders in soccer balls, car tires and even explosives like C4. With a resume like that, polyisobutylene can obviously stand up to being chomped by your teeth, but it’s also really difficult to actually destroy. For instance, swallowed gum will survive a trip through your digestive tract essentially unscathed, which means that the millions of tons of gum that ends up in landfills each year will be sitting there for ages to come.

Gathering used gum

Fortunately, polyisobutylene can also be recycled, albeit not in the blue bins you may have at your home or office. We’ve been recapturing polyisobutylene from old tires for years, and it turns out that extracting it from wads of chewing gum is a feasible process as well. So instead of sitting on sidewalks or in landfills for ages, the synthetic rubber can be remade into reusable cups, galoshes, or even shoe soles. The catch in this kind of recycling is simply getting the gum gathered up in the first place.

Getting people to specifically recycle their gum may be Anna Bullus’ major innovation. While she’s been coming up with attractive products that promote gum as a recyclable material, she’s also made Gumdrop bins, which are special bins meant to exclusively collect old chewing gum. The bright pink, spherical bins are placed at eye level, with the intent of being as conspicuous as possible so people will pay more attention to how they dispose of their gum. They’re obviously not widely available yet, but cities and campuses that have been using them have seen some success. Aside from the rain boots and other products that can be made from the recycled polyisobutylene, there’s also been a reduction in the amount of gum dropped off the ground. Since scraping gum off a sidewalk can be ridiculously expensive, simply giving people more reasons to keep their gum off the ground makes this kind of recycling cost effective.

Tasty tree sap

If you don’t have anything like gum drops in your area, your community would probably appreciate it if you at least switched to chicle-based chewing gum. Chicle is made from tree sap, making it a bit more renewable than anything made from petroleum. It also biodegrades more quickly, so while it won’t be made into shoes, it won’t be sitting on sidewalks for quite so long either.

Source: World Hacks: A surprising new afterlife for chewing gum by Dougal Shaw, BBC News

On February 26th, 2018 we learned about

A quick look at battery leaks and longevity

“Daddy, why do batteries rot?”

While my third-grader is planning to use potatoes and lemons in an upcoming science fair project, I don’t think my five-year-old was thinking of produce when he asked this question. Most batteries are made, or at least sealed, in inorganic materials, and so they’re unlikely to become lunch for bacteria or fungus like an old apple might. A leaking alkaline battery does look a little like it’s growing mold though, so that seemed like a decent place to start with his question.

Bleeding batteries

The white crust that can build up on a battery is the byproduct of a leak in the battery’s shell. As a battery is used, ages, or just reacts to changes in temperature, the internal chemical reactions produce extra hydrogen gas. In good conditions, that gas can be vented through a gasket at one end of the battery (along the negative end of a AA battery, for instance) so that pressure doesn’t build up in the shell and cause it to burst. If the hydrogen is produced too quickly for the gasket to handle, pressure will build up and rupture the shell, allowing some of the potassium hydroxide, which is the battery’s electrolyte, will start to leak out.

Potassium hydroxide is a caustic base, and can cause eye, skin and respiratory irritation. You don’t want to touch or inhale it, which is tricky since you won’t usually see that it’s there. The white crust you do see on a leaky battery is actually potassium carbonate, which is the product of leaking potassium hydroxide reacting with carbon dioxide in the air. The resulting power is a bit like rock salt, and is basically inert. However, since it’s likely to have bits of the liquid electrolyte on it, it’s still best to avoid handling it.

Lifeless lithium-ions

Batteries that have burst shouldn’t be used, but they might not be “dead” in the way my five-year-old was thinking. Another form of battery decomposition is the way a battery can lose its charge over time, even when it’s not being used. You may have run into this with the rechargeable lithium ion batteries in your cell phone or laptop, assuming you’ve put them down long enough for them to lose their charge.

There are two main reasons for a rechargeable battery to unexpectedly turn up dead. The first is that irregular charging cycles and changes in temperature wear the battery’s cathode out faster. Since the cathode helps control the flow of electrons through the battery’s electrolyte, its degradation reduces how much the battery can be recharged. Eventually, its capacity is reduced, and your device seems to run out of juice in what feels like the blink of an eye. Alternatively, a battery that is left with no charge at all will likely trigger a protection circuit, preventing the battery from ever charging again to avoid putting power through what may be damaged cells.

Used-up alkalines

From the look on my five-year-old’s face, this wasn’t the “rot” he was thinking of. He just wanted to know why batteries in his toys get used up, which is actually a similar scenario to the depleted rechargeable batteries described above. To simplify things a bit, an alkaline battery creates power by moving electrons between the manganese dioxide cathode and the zinc anode. Those materials are consumed in this reaction, eventually leaving the battery with no way to get electricity moving again. So to return to the biological analogies my son seemed to favor, it’s a bit more like the battery runs out of food, although in the case most AAs, we don’t have a way to feed them again later.

Source: Alkaline battery, Wikipedia

On February 1st, 2018 we learned about

Some of the first industrial-scale metalworking was made in Medieval India

You’ve probably never tried it at home, but distilling zinc isn’t easy. Heating zinc to its 1675° Fahrenheit melting point doesn’t give you a nice, pure liquid, but a reactive gas. In a standard furnace, you can expect that gas to rise into the air where it will immediately bond with any available oxygen, leaving you zinc-oxide instead of the metal you were after. It’s no surprise that the first patent on this process didn’t arrive until the 18th century in England. Except for the fact that this process was already in use on an industrial scale in India nearly a thousand years before that.

Treatises dated to the first millennium AD have been found that describe a process to handle the tricky process of distilling zinc ore. A ceramic container, combined with water and organic materials, was heated over a simple charcoal fire. With no widely known labels for lab equipment available, the manual describes the ceramic container as looking like an eggplant, and the vessel that would collect the distilled zinc as a thorn apple flower.

Distilling zinc on a massive scale

Proving that the method described was put into practice, archaeological evidence has found that it was scaled up significantly by the 14th century. Near a zinc mine in the Aravalli Hills of Rajasthan, seven furnaces have been found, each containing 36 of the eggplant-shaped containers. At full strength, this would have produced around 55 pounds of distilled zinc a day. Other furnaces dated to the 16th century show continued innovation, with 108 larger vessels that probably produced closer to 110 pounds of zinc a day.

If those numbers weren’t impressive on their own, the craftsmanship of the furnaces and other components indicate that this was a sophisticated, well-managed foundry. While earlier furnaces look hand-made, later models have uniform parts throughout. It’s presumed that the operation of these facilities would have required coordination between many different parties, all the way to the Maharajah himself.

So what made that zinc worth the invention of industrial chemistry? Northern India lacked tin for the most part, which meant that people couldn’t harden their copper into bronze. However, large amounts of zinc allowed for the production of brass. Brass, which can have a yellow color and luster similar to gold, was apparently used for a variety of purposes. Brass artifacts from the Medieval India range from coins, jewelry, utensils, statues and religious icons. Unfortunately, the advanced distillation procedures that enabled much of this production was largely lost after the Mughals invaded India. Eventually, this squashed local production so much that zinc was imported from China and finally after the 18th century, Europe.

Source: The origins of chemical industry by Paul Craddock, Chemistry World

On January 31st, 2018 we learned about

Corncobs and sugar are the primary ingredients in a new process to produce plant-based plastics

Scientists from the University of Wisconsin are reporting progress on getting more sugar into soda bottles. While this may sound like they’re aiming to compete with Jolt or Mountain Dew, they’re actually investigating the bottles themselves, or more specifically, the plastic they’re made of. Plastic bottles, food packages and polyester fabric all use polyethylene terephthalate (PET), which is produced from petroleum, and thus requires a huge amount of carbon emissions in their production. If costs can be managed, some of that plastic production may be replaced with a material made from sugar and corncobs, reducing the amount of oil needed for the million plastic bottles used every minute in the United States alone.

The sugar-based product is polyethylene furandicarboxylate (PEF), a plastic doesn’t require any oil to produce while at the same time doing a better job at preserving foods than PET. The key to its production is furandicarboxylic acid (FDCA), which has been available for years, but generally considered too expensive to make PEF practical. Fortunately, corncobs have turned out to be a good source for a solvent that can lower the manufacturing costs of FDCA while also reducing the amount of sugar needed in the first place. If that weren’t enough, this process removes the need for expensive reactors to handle other acids associated with PET production, while also allowing some of the corncob-solvent to be recycled for the next round of production.

A catch with the costs

This may seem like an obvious win, but unless we’re willing to pay more for our bottles and packages, it’s not clear that it will be cheaper than PET yet. A metric ton of PEF made from sugar and corn would be around $45 more than the same amount of PET, although researchers are hoping to shave $200 off that price after they optimize the system. They’re also competing with other sugar-based processes that don’t require the use of platinum, a metal rare and expensive enough to offset some of the gains from making use of all those corncobs.

The final concern is that this process may end up being too good, and then backfiring. If costs can be brought down, the demand for plastic is so high that sugar and corn prices might get pushed up. We’d then be left with the weird trade-off of a carbon neutral, or potentially carbon-negative, product that’s so cheap it makes the sugary beverages it contains more expensive. Then again, we shouldn’t be using this much plastic in the first place, so anything to reduce their impact on the planet is probably worth it in the long run.

Source: Here's a sweet recipe for cheap, green plastic—sugar and corncobs by Roni Dengler, Science

On January 7th, 2018 we learned about

Chemical imaging technique takes apart a painter’s process without injuring the canvas

When you’re in the art museum, seeing that a painting is made in “oil” or “mixed media” sometimes feels more like a formality rather than useful information. Fortunately, a new technique for paint analysis promises to add a lot more useful detail to those descriptions, revealing exactly which paints were used, and even what order they were applied to the canvas. Modern paintings produced with mass-produced commercial paints probably won’t yield many surprises, but by looking at the exact pigments and layering in older paintings, art historians will gain a much richer understanding how these paintings fit into the world that produced them.

The technique is called macroscale multimodal chemical imaging, and is actually a combination of earlier forms of chemical analysis. However, the combination of hyperspectral diffuse reflectance, luminescence and x-ray fluorescence can now produce data that offer more than the sum of their parts. Instead of simply giving researchers a graph of values, the technique uses each form of analysis to create images for each type of pigment used in a painting. The visual relationship of each layer of paint is then made much more obvious, as the strokes, revisions and essentially, choices of the artist are laid out for your eyes to see.

Making sense of materials

Additionally, this technique can identify the chemical composition of each layer of pigment. Knowing how each color was sourced can then provide insight into the difficultly, cost and importance of a painting at the time it was produced. For instance, a rare blue pigment used in a portrait indicates that the patron felt it was worth investing in those materials, helping historians better understand the story behind the painting.

Finally, none of these details need to harm the painting to be analysed. Many ancient objects are quite fragile, and so there’s an interest in avoiding destructive sampling, even if those samples are tiny. When working with ancient, one-of-a-kind artwork, deconstructing the artist’s process without taking apart the painting itself should prove to be a great new addition to historian’s tool kits.

Source: A New Scientific Technique Reveals How Ancient Humans Made Art by Taylor Dafoe, Artnet

On November 1st, 2017 we learned about

The origins of the artificial flavors that make your antibiotics taste like bubblegum

In 1972, Beecham Laboratories made a significant advancement in medicine that has improved the lives of millions of children around the world. They launched Amoxil, an antibiotic related to penicillin that today is often sold under its generic name, amoxicillin. The exact bacteria-busting power of Amoxil were surely great, but the real innovation may have been the sweet, vaguely-bubblegum flavor that was mixed in with the otherwise bitter liquid. By adding what tasted like a spoonful of sugar to every dose, getting kids to follow through on their course of antibiotics became easier than ever.

Battling bitterness with sweet, syrupy relief

While the weirdly chalky flavoring of amoxicillin may stand out in many people’s experience as the best part of a childhood ear infection, but it certainly was not the first time flavor was added to medicine. In the Middle Ages, when illness was believed to be an imbalance of the “four humors,” treatments were based on flavor. So if you felt sad or sour, the recommendation would be that you should avoid acidic foods and eat something sweet instead. (“I feel sad!” shouts the eight-year-old). While sugar has been linked to pain-relief, a lot of these treatments were probably only effective as placebos, and even then it seems hard to feel optimistic over the prospect of being prescribed something to restore your phlegm.

Herbal remedies offered more efficacy, but like penicillin, often taste very bitter. This bitterness was seen as a sign of the herbs potency, but it didn’t make them any more attractive to patients. Rather than have people munch plants directly, herbs were dissolved in alcohol and mixed with sugary syrups. It was nothing as exciting as the wild cherry or banana flavors you might find today, but the sweetness made medications much more palatable.

A fruit salad’s worth of synthetic flavors

By the 1800s, chemists were starting to isolate specific compounds that matched the flavors and smells of various foods. These compounds were usually esters that turned up in various contexts, like the cherry flavors that were found in byproducts of everything from alcohol distillation to coal processing. Methyl anthranilate, which in Germany was associated with orange blossoms, reminded people of Concord grapes (Vitis labrusca) in the United States. It’s now the basis for all the grape flavored candy and cough syrups on the market, even if it doesn’t taste like the Vitis vinifera grapes we snack on or make into wine. Banana flavors have a similar disconnect these days, as the isoamyl acetate that’s added to food and medicine comes from the Gros Michel banana, a cultivar that hasn’t been available since the 1950s. The flavor was included in candies in the United States before the average consumer could buy any bananas, but now it clashes with our expectations of Cavendish banana flavor.

All these flavors promised tastier candies and medicines, which became a serious problem by the 1960s. So called “candy aspirin” was apparently sweet enough to be compared to SweeTarts, a fact that was not overlooked by kids who started seeking treatment for every ailment they could think of. Many children were so drawn in by this flavor that they started eating aspirin like literal candy, and increasing aspirin poisonings by 500 percent nationwide. In response, the flavor was toned down and child safety caps were introduced to keep smaller hands away from medications.

Flavored medicines beyond bubblegum

Anyone with a young child knows that these flavored medications haven’t vanished entirely though. Dimetapp is still flavored like Concord grapes, and amoxicillin is still the strawberry-banana-cherry-cinnamon mash-up that we recognize as bubble gum. Chemistry hasn’t stopped innovating though, opening up a larger array of options than ever before, including mango, watermelon, and chocolate. If that weren’t enough, your dog can get its medicine flavored as beef, tuna, chicken pot pie, bacon, salmon, and yes, bubble gum. No reason for dogs to miss out on one of medicine’s greatest achievements, right?

Source: A Search for the Flavor of a Beloved Childhood Medicine by Julie Beck, The Atlantic

On October 11th, 2017 we learned about

What makes smoke from wildfires so bad to breathe in?

My neighborhood, while thankfully a safe distance from being actually immolated in the fires spread across northern California, is starting to look a little scary. The skies are darkened with the red tint of smoke, and trees just two blocks away are starting to be obscured by the thickening particulate. My third grader is… not taking it well. She’s nervously asking how close we are to the fires, if her aunt further north is safe, and if she should start expecting ash to start falling out of the sky, a scenario she only knows from stories about when a baby in southern California. Parental instinct leads me to try and calm her, but with at least 160,000 acres burned this week, how worried should we be about all this smoke?

Byproducts of burning plants

The smoke from forest fires has a lot of different ingredients. Trees’ and other plants’ exact combinations of cellulose, tannins, oils, waxes and more can create a wide range of chemical byproducts of a fire. Smoke from a burning forest is likely to contain carbon dioxide, carbon monoxide, water vapor, hydrocarbons, nitrogen oxides, benzene, formaldehyde, trace minerals and other particulate matter. While that may sound like a big scary list, your body can bounce back from the bigger molecules it inhales pretty well, with only temporary irritation to sensitive tissues in the eyes and respiratory tract. The items that are more worrisome are the tiny particles less than 2.5 micrometers in diameter, around 30 times thinner than a human hair. These minuscule particles can get lodged deep in your lungs, where they can cause more lasting damage to cells.

Avoiding inhalation

There are, unfortunately, a lot of health concerns with breathing in too much smoke. Older people, people with compromised hearts or lungs, and of course, growing kids, are all considered to be especially at risk when the air is too polluted. Kids with asthma are probably at the most risk, as irritation can cause their airways to close enough to completely restrict breathing, but anyone who’s lungs are either sensitive or still growing should really avoid breathing hard outdoors if at all possible. Breathing in some particulate is unavoidable— the goal is just to minimize exposure and impact.

Some folks wear dust or surgeons’ masks to try to stay safe, but most of those masks aren’t designed to block the tiny particulate that is of the most concern. Even if you do have an N-95 or P-100 respirator, it needs to fit against your face without gaps, otherwise you’ll end up sucking in particulate you were trying to filter out. Staying inside is probably a safer bet, using air conditioners to help filter the air. If that’s not an option, you may want to look for Clean Air shelters, or even climate controlled malls and businesses, as a way to avoid sucking in too much smoke.

Hazards from flaming houses

The fact that 3,500 buildings have burned down in these wildfires complicates things a bit. Houses these days are packed with a lot of plastics, which burn hot and fast, releasing more toxic and corrosive gasses like hydrogen chloride, phosgene and even hydrochloric acid. Thankfully, most of these won’t be released in high enough concentrations to affect the surrounding areas, and are more commonly issues for firefighters entering burning buildings. In those scenarios, the to big worries are carbon monoxide and cyanide, both of which are odorless, colorless and most dangerous in hot areas with restricted airflows, like a structure fire. Both chemicals restrict your body’s access and use of oxygen, and can be lethal in under ten minutes’ exposure. Again, this isn’t something you need to worry about in a smokey neighborhood downwind of a fire because concentrations each compound will probably be too low to cause that much harm, but it’s something to consider if you’re ever asked to evacuate, as staying in your home may put you and firefighters in much more risk if you need rescuing later on.

Extended influence

If all this weren’t enough, there’s a chance that wildfires are affecting you even if you can’t see the smoke. Global surveys of air quality have found that large forest fires release enough smoke to be detectable on a large scale, even beyond areas where the smoke is visible. In some cases, there are things that can be done to try to mitigate the impact of forest fires, from direct prevention to reducing carbon emissions that raise the world’s temperatures and make fires more likely in the first place.

For now, everyone’s rubbing their eyes, doing a bit more sneezing, and hoping that the fires can be contained before things get too much worse. If waiting things out feels too passive,  making donations to the people whose lives have been more directly uprooted by the fires has felt helpful as well.

Source: Wildfire Smoke: A Guide for Public Health Officials by Harriet Ammann, Robert Blaisdell, Michael Lipsett, et al., Environmental Protection Agency

On September 28th, 2017 we learned about

Test authenticating paintings’ particular yellow pigment turns up with problems of its own

By the time you graduate from that first batch of eight crayons, you start to learn that just how much variability there is between one hue and it’s closest cousins. Despite similar naming conventions, you wouldn’t arbitrarily substitute Strawberry for Raspberry Red. These differences can even persist in what is supposedly the same color, depending on its formulation. A pigment known as Indian yellow is so particular it’s origins have become the stuff of slightly unbelievable legend. More importantly, the pigment has also become the center of controversy in identifying the dates and possible authenticity of many famous paintings from the early 1900s.

One of the best places to see Indian yellow is in the sunsets painted by Joseph Mallord William Turner. The impressive but not overly-saturated yellow of the late afternoon sun in Caernarvon Castle, for instance, is an example of a pigment that originally became popular with European painters back in the 14th century. Supposedly, it was produced only in Bihar province in India, where cows were fed only mango leaves. The cows’ urine was then collected and dried so that the remaining concentrate could be mixed with oil, creating the subtle hue that many artists desired. This method of production then continued until the early 1900s when it was halted out of concern for the cows, although that also happens to be around the same time when synthetic dyes and pigments were becoming more widely available.

Testing paint with the wrong test

Whether or not it was ever in a cow’s bladder, true Indian yellow is a magnesium salt of euxanthic acid. Its synthetic competitors were generally azo-based dyes, including tartrazine, a compound found in food coloring today. The synthetic, “fake” Indian yellow may have looked the part to most observers, but it was quite different on a molecular scale. This has proved useful to historians and curators, as the type of yellow could be used to prove when a particular painting was created (or at least altered or repaired.) By comparing the chemical signature of a euxanthic acid against an unknown painting, a researcher could tell if it was painted before or after the early 1900s. Theoretically.

This system was recently discovered to have a major flaw. People’s understanding of the two different paints was correct, but the “real” Indian yellow that they were often comparing new samples against was discovered to respond to measurements just like “fake” tartrazine pigments did. Essentially, people were checking for forged or altered paintings by comparing them to another “fake.” While figuring out how this mix-up occurred in the first place will take some time, curators are now looking to double check the paintings already in their collections. Fortunately, only Indian yellow made with euxanthic acid will fluoresce under ultraviolet blacklights. This low-cost test promises a quick alternative method of authentication, at least until a new spectral analysis standard can be established.

Source: The hunt for Indian yellow by Raychelle Burks, Chemistry World

On September 27th, 2017 we learned about

How chemistry lets us put pumpkin, orange or butter flavors in practically any food

It’s fall, which means every other item at my local Trader Joe’s now has pumpkin in it. Or the essence of pumpkin, at least. You know, that lovely cis-3-Hexen-1-ol (C6H12O) that your nose senses after you slice into a big, orange gourd to carve a jack-o-lantern. Or the always nostalgic dash of sabinene (C10H16) that you taste in a good pumpkin pie, and naturally, pumpkin tortilla chips, which are also a thing… These products probably do have their fair share of pumpkin puree, but sometimes smushed pumpkin isn’t even what we really expect to taste when offered a “pumpkin flavor” product. This isn’t really a problem either way, since really what’s going on pumpkin and other flavors is just some refined manipulation of how we perceive flavor in the first place. And probably sugar.

Compounds that are convincing to your nose and brain

You might not have anything labeled cis-3-Hexen-1-ol on your spice rack, but it’s actually one of the various compounds you’re likely to notice when you cut into a ripe pumpkin. Alongside a few other alcohols and aldehydes, the right ratios of these molecules hitting the right smell receptors in your nose will get your brain working to identify what is causing the aroma. With a pumpkin in front of you, that particular blend gets labeled as “fresh pumpkin smell” in your memory, although none of those compounds are terribly unique. When you taste (and smell) the food you eat, your brain is simply referencing memories of other times you’ve had those particular smell receptors get activated in some particular proportion.

Now, cis-3-Hexen-1-ol is a decently large molecule, but only one portion of it is needed to activate a smell receptor. Rather than have a receptor that can accommodate the entire molecule at once, your nose only really cares about the OH at the end. This is very convenient for chemists, who can attach that smell signifier to other compounds that may be more stable, cheaper or somehow easier to work with than what the pumpkins make themselves. It’s a concept that gets used in tons of different foods, with these artificial flavors often being mixed back into the foods they originated in.

Close control over foods’ flavors

As food production shifted to industrial scales in the early 20th century, manufacturers needed food that could survive longer in transport and on shelves, bring down costs, and also taste consistent from one helping to the next. As with pumpkins, oranges have had their chemistry parsed to see which molecules trigger the experience of “orange flavor,” so that it could be used in other products, as well as orange juice itself. By adding something like ethyl butyrate to orange juice, manufactures can be sure that a crop of bland oranges won’t tank their sales for a season. Similarly, diacetyl was added to products to give them a buttery taste, but the flavor association was so successful that creameries now spike actual butter with the compound, so that butter tastes more like what our brains think of as butter.

In the case of the deluge of seasonal pumpkin products, we also have to accept that we’re not sure what we want to taste. While cis-3-Hexen-1-ol is found in actual pumpkins, that’s not a smell you’re really looking for in your coffee or pumpkin biscotti (which is also a thing.) In those cases, the target flavor is actually pumpkin pie, which is why recipes also include sabinene for nutmeg, eugenol for cloves, and cinnamaldehyde for cinnamon. As ubiquitous as this now seems, it’s not an easy batch of flavors to get right since one person’s perfect pie might not match the expectations of someone else. This led Jelly Belly candies to even temporarily abandon their attempt at pumpkin pie flavor, at least until they embraced the variability inherent in the task by billing the candies as their “family’s” own recipe. Fortunately for manufacturers, sugar helps smooth things out considerably, as it’s certainly a flavor that our brains remember as “yummy.”

Source: The Absurd History of Artificial Flavors by Alison Herman, First We Feast