100 Fun Facts About Food Science

The browning reaction between amino acids and sugars that flavours seared steak is named after which chemist?

Louis Camille Maillard, a French physician and chemist, first described the reaction, which races along at roughly 140 to 165 °C; that is why dry heat browns food while boiling water cannot.

When sucrose caramelizes, it breaks down into which two simple sugars?

Heat first splits sucrose into Glucose and fructose, which then dehydrate and polymerize into the brown caramel compounds; unlike the Maillard reaction, no amino acids are needed.

Which Japanese chemist identified umami as a distinct taste in 1908 after noticing the flavour of kombu?

Kikunae Ikeda isolated glutamate from kombu broth at Tokyo Imperial University and patented a way to make monosodium glutamate, launching the seasoning sold as Ajinomoto.

Umami receptors respond mainly to glutamates and which other class of compounds found in meat broths?

Nucleotides such as inosinate from meat and guanylate from mushrooms amplify glutamate's umami taste, which is why dashi pairs glutamate-rich kombu with bonito flakes.

Which two wheat proteins form the elastic network we call gluten?

Gliadin and glutenin are wheat's storage proteins; once flour is wetted and kneaded they bond into gluten, which makes up roughly 75 to 85 percent of bread wheat's protein.

Which everyday sauce is an emulsion of oil, egg yolk and an acid?

Mayonnaise stays stable because lecithin in the egg yolk coats the oil droplets and keeps them apart; a popular origin story traces it to Mahón in Menorca in 1756.

The word 'emulsion' comes from a Latin verb meaning what?

The Latin verb emulgere means 'To milk out'; the word was first applied to milky liquids such as almond milk, and milk itself is fat droplets dispersed in water.

Louis Pasteur's 1860s research that gave pasteurization its name was originally aimed at preserving what?

Wine was Pasteur's target: in the 1860s he showed that briefly heating it to about 50 to 60 °C stopped it souring, and the process kills most bacteria while leaving spores intact.

Georges Pralus devised sous vide in 1974 to improve which dish?

Foie gras lost far less fat and kept a better texture when Pralus sealed it in plastic and cooked it slowly in a water bath at Restaurant Troisgros; sous vide is French for 'under vacuum'.

Who coined the term 'molecular and physical gastronomy' in 1988?

Nicholas Kurti and Hervé This launched the term in 1988; Kurti's 1969 Royal Institution lecture The Physicist in the Kitchen famously injected brandy into mince pies with a syringe.

Spherification uses sodium alginate together with which salt?

Calcium chloride supplies the calcium ions that cross-link alginate chains into a thin gel membrane around each drop, so a liquid centre stays sealed inside the sphere.

Which restaurant, run by Ferran and Albert Adrià, brought spherification to modernist cuisine?

elBulli sat in Cala Montjoi near Roses on the Costa Brava; Ferran Adrià joined it as a line cook in 1984, aged 22, and the restaurant served its last meal in 2011.

Why can birds eat chilli peppers without feeling the burn?

Their TRPV1 receptor ignores capsaicin because the bird form of the heat-sensing channel lacks the mammalian binding site; that suits the plant, since birds spread seeds intact while mammal molars grind them.

In which part of a chilli pepper is capsaicin most concentrated?

The placental tissue, the pale pith that holds the seeds, carries the capsaicin-secreting glands; the seeds pick up heat only because they sit against it.

Wilbur Scoville, whose scale measures chilli heat, worked in what profession?

Pharmacist Wilbur Scoville devised his dilution test while working for the drug firm Parke-Davis, thinning pepper extract in sugar water until a tasting panel could no longer detect heat.

How many trained tasters sat on the panel in Scoville's original organoleptic test?

Five tasters formed the panel: Scoville diluted an alcohol extract of the pepper in sugar water until the panel could no longer sense heat, and that dilution ratio became the pepper's rating.

Pectin, the gelling agent that sets jam, takes its name from a Greek word meaning what?

Congealed is the sense of Greek pektikos, the root of pectin; apples, quince and citrus peel are rich in it, while strawberries and cherries have little and need added pectin to set.

Which Harvard professor patented the phosphate baking powder later sold as Rumford?

Eben Norton Horsford, Harvard's Rumford Professor, patented a calcium acid phosphate leavening in 1856 and co-founded the Rumford Chemical Works to sell it; Alfred Bird had sold a cream-of-tartar powder in England from 1843.

Nicolas Appert, the 'father of food science', preserved food by sealing it in what and boiling it?

Glass jars and bottles, corked and wired shut, were Appert's vessels; the French government paid him 12,000 francs in 1810 on condition that he publish his method.

Which civilisation was freeze-drying potatoes into chuño as early as the 13th century?

The Inca left potatoes out on freezing Andean nights and trampled the water out by day to make chuño; the modern process took off in the Second World War to preserve blood plasma and penicillin.

Nixtamalization, soaking maize in limewater, helps prevent which deficiency disease?

Pellagra is niacin deficiency; the lime soak frees the niacin locked in maize so the body can absorb it, and it also loosens the hulls and softens the kernels for masa.

Storing bread where makes it go stale fastest?

In the refrigerator, starch recrystallises fastest at temperatures just above freezing, so chilled bread stales within about a day; freezing halts the process and room temperature slows it.

When you boil an egg, what happens to its proteins to make the white turn firm and opaque?

They denature: heat unfolds the egg's albumin proteins, which then tangle into a solid opaque network; acid and salt can also unfold proteins, which is how ceviche 'cooks' fish without heat.

Egg white is roughly what percentage water?

90 percent of egg white is water, with nearly all the rest protein such as ovalbumin; even so, the white holds about 56 percent of the egg's total protein.

The term 'supertaster' was coined by which experimental psychologist?

Linda Bartoshuk coined the term at Yale in the 1990s for people who find the bitter compound PROP intensely strong, a trait she linked to a higher density of fungiform papillae.

Miraculin, from the West African miracle fruit, makes sour foods taste how?

Sweet is how lemon juice tastes once miraculin binds to the tongue's sweet receptors and switches them on in acid; the protein itself is not sweet, and the effect lasts an hour or two.

At roughly what temperature does a popcorn kernel's hull finally rupture?

180 °C is where the steam pressure inside finally bursts the hull; the kernel then expands to 20 to 50 times its volume as the superheated starch puffs into foam.

A popcorn kernel needs about what moisture content inside its hull to pop?

A kernel at 14 to 20 percent moisture holds enough water to flash into steam and build roughly 135 psi inside before the hull gives way; drier kernels stay unpopped.

Besides its high sugar concentration, which property helps honey resist spoiling?

Its acidic pH, around 3.9, comes from gluconic acid that bee enzymes make from glucose, alongside hydrogen peroxide; few microbes grow in something that acidic with so little free water.

Which gas, also a plant hormone, is used commercially to ripen fruit?

Scrubbing it out of storage air delays ripening, which is how apples last all year.

Cutting an onion releases enzymes called alliinases that lead to which tear-inducing compound?

Syn-propanethial S-oxide forms when a second enzyme, lachrymatory-factor synthase, rearranges the sulfenic acid that alliinase releases; the volatile gas drifts up from the board and stings the eyes into tears.

Roughly what proportion of adults worldwide have lactose malabsorption?

65 percent of adults worldwide are estimated to have reduced lactase activity after infancy; as few as 5 percent of northern Europeans are affected, versus roughly nine in ten in parts of East Asia.

Chymosin, the key enzyme in rennet, curdles milk by acting on which protein?

Casein is the target: chymosin clips kappa-casein, the protein that keeps milk's casein micelles dispersed, so they clump into curd; much commercial chymosin comes from genetically engineered microbes rather than calf stomachs.

Sourdough starter is a partnership between wild yeast and which kind of bacteria?

Lactobacillus species produce the lactic and acetic acids that give sourdough its tang; San Francisco's signature strain was first described in 1971 and named Lactobacillus sanfranciscensis after the city.

Which yeast species converts sugars into carbon dioxide and alcohol in bread and beer?

Saccharomyces cerevisiae, the brewer's and baker's yeast, ferments sugars into carbon dioxide and ethanol; its name is often used as a synonym for yeast, though yeasts span two fungal phyla.

Adding salt to ice around an ice-cream churn works because it does what?

Lowers the melting point of the ice: salt dissolves into the meltwater and the brine can fall to about minus 20 °C, cold enough to pull heat out of the cream mix through the churn wall.

Which 19th-century process makes chocolate smoother by prolonged mixing and grinding?

Conching was introduced by Rodolphe Lindt in Bern in 1879; hours of grinding in a shell-shaped trough shrink the sugar and cocoa particles and drive off harsh volatile acids.

Coenraad van Houten's 1828 hydraulic press squeezed what out of chocolate liquor?

Cocoa butter, the fat that makes up roughly half of chocolate liquor, was pressed out, leaving a cake ground into cocoa powder; white chocolate is made from that butter with milk and sugar but no cocoa powder.

Table salt is often fortified with which element to prevent goitre?

Iodine is needed to make thyroid hormones; without it the thyroid swells into a goitre, and iodised salt, introduced in Switzerland and the United States in the 1920s, nearly eliminated the problem there.

Heston Blumenthal's Fat Duck became famous for which unusual dish?

Bacon-and-egg ice cream became the signature dish at Blumenthal's restaurant in Bray, Berkshire, which topped the World's 50 Best Restaurants list in 2005.

Harold McGee's landmark 1984 book on kitchen science is titled what?

On Food and Cooking first appeared in 1984 and was heavily expanded for a 2004 edition; McGee later wrote a New York Times column, The Curious Cook, debunking kitchen folklore.

Modernist Cuisine author Nathan Myhrvold was formerly CTO of which company?

He spent 13 years at Microsoft and became its first CTO in 1996.

In what year was the browning reaction between amino acids and sugars first described?

1912 is when Maillard reported the reaction to the French Academy of Sciences while trying to reproduce biological protein synthesis; USDA chemist John E. Hodge worked out its mechanism in 1953.

Which probable carcinogen can form as a by-product of the Maillard reaction at high temperatures?

Acrylamide forms when the amino acid asparagine reacts with reducing sugars above about 120 °C, which is why fries and crisps carry most of it; lower temperatures or added asparaginase discourage it.

Applying lye to pretzels darkens them faster because the Maillard reaction speeds up in what environment?

Alkaline conditions deprotonate amino groups, making them more nucleophilic, so the sugars and amino acids react faster; that is why lye-dipped pretzels brown to a deep mahogany.

Which volatile compound with an intense butter-like taste is released during caramelization?

Diacetyl, the same compound that flavours butter and butterscotch, is released in the first stage of caramelization; the brown colour comes from polymers called caramelans, caramelens and caramelins.

At roughly what pH is the rate of caramelization slowest?

Around 7, neutral pH, is where the reaction crawls; both strongly acidic and strongly basic conditions accelerate it, as do impurities such as the molasses in brown sugar.

Butter is unusual among food emulsions because it is which type?

Water-in-oil describes butter: tiny water droplets sit inside a continuous fat phase, the reverse of hollandaise, cream and homogenised milk, which are all oil-in-water.

The spontaneous emulsion that clouds pastis or absinthe when water is added is called what?

The ouzo effect is a spontaneous nanoemulsion: anethole and other anise oils dissolved in the spirit form droplets of a few hundred nanometres when water dilutes the alcohol, scattering light into a milky cloud.

In which US city is the Institute of Food Technologists headquartered?

Chicago houses the Institute of Food Technologists, founded in 1939; its definition of food science runs from the causes of food deterioration to the principles of processing.

Carmine, the red colouring listed on food labels as E120, is made from which crushed creatures?

Cochineal insects live on prickly pear cacti, and their red has been used as a dye since about 700 BC. The pigment also appears on labels as natural red 4.

Which fresh fruit contains bromelain, an enzyme that stops gelatin desserts from setting?

Pineapple is rich in bromelain, a protein-cutting enzyme that snips gelatin apart before it can gel. Canning deactivates the enzyme, so tinned fruit sets fine.

Which cheaper root, dyed green, is widely used in place of real wasabi outside Japan?

Horseradish gets its nose-tingling kick from allyl isothiocyanate, the same volatile compound that gives true wasabi its pungency. The real plant is hard to farm, which keeps it scarce and costly.

Botulism, a paralysing illness caused by a bacterial toxin, is named after the Latin for which food?

Sausage is botulus in Latin, though improperly canned and fermented foods are common culprits too. The bacterium can also lurk in honey, which is why babies under one should not eat it.

Which oxygen-storing protein in muscle gives raw beef and lamb their red colour?

Myoglobin holds oxygen in reserve inside muscle cells, ready for bursts of effort. Heat changes the pigment, which is why a steak turns from red to brown as it cooks.

Percy Spencer discovered microwave cooking at Raytheon while working on which wartime technology?

Radar magnetrons melted a candy bar in his pocket, the story goes, so he tried popcorn kernels next and made the first microwaved popcorn.

Variants of the smell-receptor gene OR6A2 make which leafy herb taste like soap to some people?

Cilantro, called coriander leaf outside North America, owes most of its aroma to aldehydes. The OR6A2 receptor is highly sensitive to exactly those chemicals.

The Flavr Savr, the first genetically engineered food licensed for people to eat, was which crop?

Tomato breeders at Calgene added a reversed gene to block a rotting enzyme, hoping the fruit would soften more slowly on its way to market. It went on sale in 1994.

Which baking spice contains myristicin, which can cause hallucinations when eaten in large doses?

Nutmeg has no noticeable effect in the pinch a recipe calls for, but large doses of the ground kernel or its oil are psychoactive. Poisonings come from children's accidents and deliberate recreational use.

Clarence Birdseye devised quick-freezing after watching which Arctic people freeze freshly caught fish?

The Inuit showed him that fish frozen almost instantly in −40 °C air still tasted fresh when thawed. His multiplate freezing machine, patented in 1927, was the basis for freezing food for decades.

Which bitter compound in chocolate is toxic to dogs because they break it down so slowly?

Theobromine is several times more concentrated in dark chocolate than in milk chocolate, so the darkest bars are the most dangerous for pets.

Which legumes contain so much phytohaemagglutinin that slow-cooking alone can leave them toxic?

Red kidney beans can hold up to 70,000 units of the lectin when raw, and a slow cooker running at 75 °C may not destroy it. Boiling for at least ten minutes is the standard advice.

Bitter almonds and apricot kernels contain amygdalin, which the body breaks down into which poison?

Cyanide is released as amygdalin is digested. A derivative called laetrile was long promoted as a cancer cure, a campaign medical journals describe as textbook quackery.

Which natural toxin builds up in potatoes that have turned green after exposure to light?

Solanine is one of the potato's own pesticides, made as a defence when tubers sit in sunlight. The green itself is harmless chlorophyll, but it signals that the poison has built up too.

Mad cow disease is spread not by bacteria or viruses but by which misfolded proteins?

Prions reached British cattle through feed made from meat-and-bone meal, and the outbreak grew as that feed was given to young dairy calves.

Which industrial chemical was added to diluted milk in China in 2008 to fake its protein content?

Melamine fools the standard laboratory tests, which cannot tell it apart from genuine milk protein. Some 300,000 children were affected and 54,000 were hospitalised.

In James Lind's scurvy trial aboard HMS Salisbury, which treatment got sick sailors back on duty?

Oranges and lemons had one sailor fit for duty within six days, when the fruit ran out. The 1747 test is counted among the first controlled clinical experiments in history.

Christiaan Eijkman won a Nobel Prize after chickens fed polished white rice developed which disease?

Beriberi cleared up within days once the birds went back to unpolished rice. The missing compound, stripped away with the bran, was eventually identified as thiamine.

Golden Rice was engineered to make beta-carotene and tackle a deficiency of which nutrient?

Vitamin A is made in the gut from beta-carotene, the pigment that gives the grains their yellow colour. One of the genes added to the plant came from a daffodil.

Which amino acid in turkey is wrongly blamed for the drowsiness that follows a Thanksgiving dinner?

Tryptophan is no more plentiful in turkey than in other poultry and meats. The sleepy feeling may owe more to the carbohydrates piled on the same plate.

Which company devised the HACCP food-safety system in the 1960s while making meals for NASA?

Pillsbury had been asked to design and make the first foods for space flights. Its contractors had to identify critical failure areas and eliminate them, a first for the industry.

Which chemist ran the Poison Squad, volunteers who ate borax-laced meals to test food preservatives?

Harvey Wiley fed his volunteers borax in meat and dairy dishes while a control group went without. The studies drew national attention to the need for a federal food and drug law.

Salmonella takes its name from Daniel Elmer Salmon, an American who worked in which profession?

Veterinarian Daniel Salmon ran the government division where the bacterium was found, but the discovery itself was made by his research assistant, Theobald Smith.

Which chemist invented carbonated water by hanging a bowl of water over a vat in a Leeds brewery?

Joseph Priestley, better known for discovering oxygen, never profited from the idea. Johann Jacob Schweppe began selling bottled soda water in 1783.

Denis Papin's steam digester, shown to the Royal Society in 1679, led to which kitchen appliance?

Pressure cooker safety valves go back to Papin's design. The force he saw inside the digester led him to build a model piston steam engine in 1690.

Menthol tricks the mouth by activating TRPM8, a nerve receptor that normally responds to what?

Cold is what TRPM8 normally senses, so menthol produces a chill with no real drop in temperature, whether it is inhaled, eaten or rubbed on the skin.

Which spice contains sanshool, the compound behind a tingling, numbing buzz on the lips and tongue?

Sichuan pepper sets off a tingle that researchers liken to a 50-hertz vibration. Despite the name, it is not closely related to black pepper or chillies.

Which alkaloid, first isolated by Hans Christian Ørsted, gives black pepper its bite?

Piperine comes from the fruits of Piper nigrum, the plant behind both black and white pepper. Its discoverer is better known for showing that electric currents create magnetic fields.

The debunked tongue map of taste zones grew from a 1942 translation of a paper in which language?

German scientist David Hänig wrote the 1901 paper to show taste thresholds across the tongue. Harvard psychologist Edwin Boring replotted its graphs, and the map grew from his version.

Which plant compounds cause the dry, puckering feel of strong tea and unripe fruit?

Tannins bind to proteins and make them precipitate, which the mouth feels as dryness. Their name comes from oak bark's old use in tanning hides into leather.

Caffeine keeps you alert by blocking the brain receptors for which drowsiness-inducing chemical?

Adenosine builds up the longer you stay awake, and caffeine has a three-dimensional shape so similar that it can slot into the same receptors and block them.

Isoamyl acetate, released by a honey bee's sting to rally other bees, smells of which fruit?

Banana is the scent most people pick out, though some say pear, and the ester is also known as banana oil. It flavours candies such as circus peanuts and pear drops.

Which spice owes its golden colour to curcumin and has long been used to dye monks' robes?

Turmeric was first used as a dye, and it spread through India with Hinduism and Buddhism because its yellow coloured the robes of monks and priests.

Which pigments colour blueberries and black rice, shifting from red to blue as acidity changes?

Anthocyanins take their name from the Greek for flower and dark blue. Depending on pH they can look red, pink, purple, blue or black.

Which compound, made by bacteria from cabbage sugars, gives sauerkraut its tang and long shelf life?

Lactic acid builds up as bacteria ferment the shredded leaves. The same process sours kimchi and traditional pickled cucumbers.

Which sticky, pungent Japanese breakfast food is made by fermenting soybeans with Bacillus subtilis?

Natto is known for the sticky strings that form when it is stirred. Many people find the smell hard to take, while others relish it as a delicacy.

Quorn's meat-free mycoprotein is grown in fermentation tanks from which kind of organism?

A fungus called Fusarium venenatum, discovered in a soil sample in 1967, supplies the protein. In most products the dried culture is bound with egg white and pressed into shape.

Gelatin is made by breaking down which protein from animal skin, bones and connective tissue?

Collagen is chopped into smaller peptides by hydrolysis, a change that cannot be reversed. The word gelatin comes from the Latin gelatus, meaning stiff or frozen.

Agar, the gelling agent used in Asian desserts and laboratory petri dishes, is extracted from what?

Red algae gave agar its name as well: agar-agar is the Malay word for the seaweeds the jelly is made from. The gelling compounds come from their cell walls.

Which enzyme in human saliva starts breaking starch into sugars while food is still being chewed?

Amylase is why plain rice or potato can start to taste sugary if you chew it for long enough. The pancreas makes a second supply to carry on the work.

Which copper-containing enzyme turns the flesh of a sliced apple brown once it meets the air?

Polyphenol oxidase turns natural phenols into quinones that link up as brown pigments. Arctic apples were genetically modified to silence it, so their slices stay pale.

Which enzyme, nicknamed meat glue, bonds proteins together in imitation crabmeat and fish balls?

Transglutaminase forms bonds between proteins that strongly resist being broken down, which is why processors also use it as a binder in surimi and ham.

Drying jerky and sugaring jam both stop mould by lowering which measure of a food?

Water activity is the ratio of a food's vapour pressure to that of pure water at the same temperature. Kept below a certain level, it stops mould from growing.

Nigari, the traditional Japanese coagulant that sets soy milk into tofu, is produced from what?

Seawater leaves nigari behind once its table salt has been removed and the rest evaporated. The powder is rich in magnesium, and its name comes from the Japanese word for bitter.

A bomb calorimeter measures the energy in a food sample by doing what to it?

Burning it in pure oxygen inside a sealed vessel releases heat that warms the surrounding water, giving the food's gross energy. Wilbur Atwater adjusted such figures for how much the body actually digests.

Which phenomenon makes droplets skitter across a very hot pan on a cushion of their own vapour?

The Leidenfrost effect sets in at about 193 °C for water. Above that point a drop hovers on its vapour and takes longer to boil away than it would on a cooler pan.

Oobleck, a cornstarch-and-water mix that thickens the harder you stir it, is which kind of fluid?

Non-Newtonian fluids change their thickness with the force applied. Stirred slowly, the cornstarch mix looks milky; stirred vigorously, it feels like a very viscous liquid.

Freezer burn dries out frozen food as its ice turns straight into vapour, a process known as what?

Sublimation moves water out of the food and into the freezer's air, leaving greyish-brown leathery spots. The patches are dry rather than unsafe to eat.

The green ring around the yolk of an overcooked hard-boiled egg is a thin coating of which compound?

Iron sulfide coats the yolk when an egg is cooked for too long, but tasters report that the green layer has little effect on flavour.

Which compound, released as a chemical in fish flesh breaks down, gives stale seafood its smell?

Trimethylamine comes from TMAO, a substance that protects the proteins of marine fish from water pressure. Gas sensors that test fish for freshness are built to detect it.