The research that led to sour

How bitter taste receptors help guard against infection

Receptors for "bitter" tastes evolved to detect potentially harmful plant chemicals, such as nicotine. The receptors also trigger bacteria-fighting responses, including waving hairlike projections to bat away bacteria, ordering the release of bacteria-killing nitric oxide, and calling for antimicrobial protein reinforcements.

Taste buds have evolved to fill a wide variety of functions

Taste buds do more than let you experience your favorite food. These peripheral organs can sense the chemical makeup, potential toxicity, and fleeting experience of flavor, giving the body a chance to respond to undesirable chemicals or tell the brain that you should reach for another scoop.

How science came to understand umami

Before Dr. Kikunae Ikeda sat down in 1907 and pondered the taste of dashi, scientists typically agreed upon four types of taste: sweet, salty, bitter, and sour. He boiled 90 pounds of kelp into a resin that he then stripped of different compounds until he was left with a single ounce of brown crystals. Testing later revealed these crystals were glutamate, an amino acid and one of the protein's building blocks.

Ammonium may be the sixth basic taste

Researchers have proposed various candidates for the sixth official taste, including "fat." But research published in 2023 posits that ammonium should be considered the sixth taste since they found humans can apparently detect ammonium chloride, which the scientists describe as "bitter, salty, and a little sour." Detecting ammonia could be a survival mechanism to help detect when certain foods, including seafood, are no longer safe to eat. The work hinged on experiments with human cells exposed to ammonium chloride as well as rodent research.

Neural replays in mice help explain food aversions

Princeton University scientists published research in 2025 analyzing how mice learn to associate certain foods or flavors with feeling ill—even when there’s a time gap between eating something and feeling sick. The work, performed with grape Kool-Aid and injections of a substance that made mice sick, traced the literal “gut reaction” of how gut distress signals are linked to neural replays of what the mouse ate.

The idea of a tongue map has been discredited (but taste sensitivity varies across the tongue)

The original tongue map, created by German researcher DP Hanig, recorded taste sensitivities reported in psychological studies. His findings were later translated and taken out of context, possibly giving rise to the faulty tongue map. In fact, taste receptors in the oral cavity respond to all tastes regardless of their location.

Cats have a mutation preventing them from tasting sugar

When certain tastes (sweet, umami, bitter) become irrelevant due to a species' diet or lifestyle, the genes for those tastes degrade. In felines, scientists believe a shift to a protein-heavy diet put evolutionary pressure on the genes responsible for tasting sweetness. (Some users may encounter a paywall.)

Octopuses have taste receptors along their tentacles

Octopus suction cups are filled with modified sensory receptors that can bind with a greater variety of materials and transport a wider array of information, such as flavor, from tactile stimuli. These structures allow the animal to search for food as it crawls the ocean floor.

How texture affects taste

Texture is the brain's interpretation of several sensations, including pressure, as registered by our teeth, tongue, and finger tips, and sound, as recorded by our ears. Texture also speaks to food particle sizes—smaller than 35 microns contributes to the sensation of creamy—and the balance between flavor and mouth time, such as the crunch of a crispy chip or the bounce of a chewy caramel.

The importance of volatile aroma compounds in the flavor quality of food

Processes such as air movement and heating cause food to lose aroma molecules, which studies have shown play a major role in our sense of taste. While losing these molecules to the environment leaves fewer to be processed during consumption to intensify flavor, it can also produce previously nonexistent aroma compounds or release previously trapped ones, altering or enhancing the food's flavor.

The five most common chemicals found in modern food

Most modern processed foods rely on a number of preservatives to stay fresh from production to our plates. The most common include citric acid (preservative and flavor), sodium benzoate (preservative), xanthan gum (thickening and stabilizing), carrageenan (thickening), and red dyes 3 and 4 (for color).

Scientists determine the smells of objects in outer space

Using spectrographic techniques, scientists determine the chemical composition of planetary atmospheres, comets, and other objects in space. Combining these chemicals in labs on Earth has revealed locations in space that smell like nail polish remover, rotten fish, and urine.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Explore some of the trademarked scents in the US

Scents, when they are truly unique and identifiable to a particular brand, can be trademarked. Any trademark on a scent must pass two tests: distinctiveness and non-functionality. In order to be trademarked, the scent of a product can't be the primary purpose of that product (like a candle or a perfume), and the scent has to be distinct. Some of the trademarked scents include Play-Doh and the pain-relief patch Salonpas.

Barbecue relies on a unique scientific equation

Barbecue's distinct flavor starts with an interaction between the heat source and food, which creates a Maillard Reaction—better known to diners as those crunchy, caramelized bits on the outside.

Why the Scoville scale for measuring a pepper's heat is outdated and inadequate for sauces

Developed in 1912 by American pharmacist Wilbur Scoville, the scale is a subjective test in which testers determine the dilution at which capsaicinoids—the molecules that give peppers their heat—are no longer detectable. Modern chemical analyses can accurately quantify the amount of these molecules in peppers, which are diluted to varying degrees in sauces, thus affecting their net spiciness.

Read this analysis indicating which traditional stevia medical uses have scientific evidence

This research paper investigates the various uses of Stevia rebaudiana leaves and their extracts and concludes that the substances do hold significant potential for improving cardiovascular health and inflammatory disorders in adults, among several other potential applications. Its authors suggest that further research should examine safe dosage questions and chronic disease management approaches.

50 years of research has focused on unraveling the relationship between music and frisson

One insight reveals that musical passages with surprising volume changes or unexpected harmonies and beauty are more likely to trigger frisson, perhaps because they upend listeners' expectations.

A delicious flavor used to be made from a beaver’s butt

Love vanilla-flavored foods? Well, it was once made from castoreum - a yellowish exudate from the castor sacs of mature beavers. And the FDA regards castoreum as “natural flavoring."

Humans experience the world subjectively. What does that mean for scientific research?

When you close your eyes, do you see static or colorful patterns or an "intrinsic grey" known as Eigengrau in German? This variation of our internal experiences is just the tip of the iceberg, one that scientists are increasingly studying and...

It seems like we shouldn’t have to say this: Cheese is not like crack

While news reports may claim cheese is addictive, the facts behind the research show cheese and crack have little in common. It appears that highly processed foods with high levels of sugars and fat, rather than cheese specifically, are most closely associated with addictive-like behaviors. In fact, cheese ranked lower than foods like pizza, chocolate, and fries in terms of its addictiveness.

How scientists are using molecules found in acidophiles to develop new medical treatments

The Berkeley Pit, an open-pit copper mine in Butte, Montana, that ceased operations in 1982 and is now filled with highly acidic water, is home to various species of fungi and yeast. These extremophiles produce unique compounds that may have anti-inflammatory benefits and have already been used to create an antibiotic for staph infections.

Explore a list of 12 recipes incorporating techniques from molecular gastronomy

The recipes include popcorn shooters that taste like liquid caramel corn, almost-instant soft serve made by blending frozen fruit with sugar and fromage blanc, a fusion of fried rice and pizza, and skewered fruit coated in a broiled, glossy meringue.

Why Coke tastes different at McDonald's

Fans of the sugary soda Coca-Cola have noticed significant differences between its canned variety versus what pours forth from the fountain at McDonald's. Is there anything to the claim? Weird History Food takes a dive into this essential fast-food...

How brain cells carry information

At any moment, there is an electrical storm coursing through your body. Discover how chemical reactions create an electric current that drives our responses to everything from hot pans to a mother’s caress.

Candymaker Haribo focuses on gummies to simplify production

Focusing on a specific kind of candy gives the company expertise on texture, ingredients, factory processes, and more. The company's decentralized production allows for regional specification.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.