Ketchup or catsup is a
table condiment with a sweet and sour flavor. "Ketchup" now typically refers to tomato ketchup,
although early recipes for different varieties contained
mushroom
A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom.
The standard for the n ...
s,
oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...
s,
mussel
Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...
s,
egg white
Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens, it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms a ...
s,
grape
A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus ''Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters.
The cultivation of grapes began approximately 8,0 ...
s, or
walnut
A walnut is the edible seed of any tree of the genus '' Juglans'' (family Juglandaceae), particularly the Persian or English walnut, '' Juglans regia''. They are accessory fruit because the outer covering of the fruit is technically an i ...
s, among other ingredients.
Tomato
The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible Berry (botany), berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originate ...
ketchup is made from tomatoes, sugar, and
vinegar
Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...
, with
seasonings and
spice
In the culinary arts, a spice is any seed, fruit, root, Bark (botany), bark, or other plant substance in a form primarily used for flavoring or coloring food. Spices are distinguished from herbs, which are the leaves, flowers, or stems of pl ...
s. The spices and flavors vary but commonly include
onion
An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the onion which was classifie ...
s,
allspice,
coriander
Coriander (), whose leaves are known as cilantro () in the U.S. and parts of Canada, and dhania in parts of South Asia and Africa, is an annual plant, annual herb (''Coriandrum sativum'') in the family Apiaceae.
Most people perceive the ...
,
cloves,
cumin,
garlic
Garlic (''Allium sativum'') is a species of bulbous flowering plants in the genus '' Allium''. Its close relatives include the onion, shallot, leek, chives, Welsh onion, and Chinese onion. Garlic is native to central and south Asia, str ...
,
mustard and sometimes include
celery
Celery (''Apium graveolens'' Dulce Group or ''Apium graveolens'' var. ''dulce'') is a cultivated plant belonging to the species ''Apium graveolens'' in the family Apiaceae that has been used as a vegetable since ancient times.
The original wild ...
,
cinnamon
Cinnamon is a spice obtained from the inner bark of several tree species from the genus ''Cinnamomum''. Cinnamon is used mainly as an aromatic condiment and flavouring additive in a wide variety of cuisines, sweet and savoury dishes, biscuits, b ...
, or
ginger
Ginger (''Zingiber officinale'') is a flowering plant whose rhizome, ginger root or ginger, is widely used as a spice and a folk medicine. It is an herbaceous perennial that grows annual pseudostems (false stems made of the rolled bases of l ...
. The market leader in the United States (60% market share) and the United Kingdom (82%) is
Heinz Tomato Ketchup.
Tomato ketchup is often used as a condiment for dishes that are usually served hot, and are fried or greasy: e.g.,
french fries and other
potato dishes
The potato () is a starch#Food , starchy root vegetable, tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground Tuber#Stem tuber, stem tubers of the plant ''Solanum tub ...
,
hamburger
A hamburger (or simply a burger) consists of fillings—usually a patty of ground meat, typically beef—placed inside a sliced bun or bread roll. The patties are often served with cheese, lettuce, tomato, onion, pickles, bacon, or chilis ...
s,
hot dog
A hot dog is a grilled, steamed, or boiled sausage served in the slit of a partially sliced bun. The term ''hot dog'' can also refer to the sausage itself. The sausage used is a wiener ( Vienna sausage) or a frankfurter ( Frankfurter Würs ...
s,
chicken tenders, hot
sandwich
A sandwich is a Dish (food), dish typically consisting variously of meat, cheese, sauces, and vegetables used as a filling between slices of bread, or placed atop a slice of bread; or, more generally, any dish in which bread serves as a ''co ...
es,
meat pies, cooked
eggs, and grilled or fried meat.
Ketchup is sometimes used as the basis for, or as one ingredient in, other sauces and dressings, and the flavor may be replicated as an
additive flavoring for snacks, such as
potato chip
Potato chips (North American English and Australian English; often just chip) or crisp (British English and Hiberno-English) are thin slices of potato (or a thin deposit of potato paste) that has been deep frying, deep fried, baking, baked, ...
s.
History
The term ''ketchup'' first appeared in 1682. Recipes for many types of ketchup began to appear in British and then American cookbooks in the 18th century.
Mushroom ketchup
In the United Kingdom, from the 1600s ketchup was prepared with
mushrooms
A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom.
The standard for the name "mushroom" is ...
as a primary ingredient, rather than tomatoes.
In the United States,
mushroom ketchup
Mushroom ketchup is a style of ketchup that is prepared with Edible mushroom, mushrooms as its primary ingredient. Originally, ketchup in the United Kingdom was prepared with mushrooms as a primary ingredient, instead of tomato, the main ingredie ...
dates back to at least 1770, and was prepared by British colonists in the
Thirteen Colonies
The Thirteen Colonies were the British colonies on the Atlantic coast of North America which broke away from the British Crown in the American Revolutionary War (1775–1783), and joined to form the United States of America.
The Thirteen C ...
.
Tomato ketchup
James Mease published the first known tomato ketchup recipe in 1812. An early recipe for "tomato catsup" from 1817 includes
anchovies and insects:
# Gather a gallon of fine, red, and full ripe tomatas; mash them with one pound of salt.
# Let them rest for three days, press off the juice, and to each quart add a quarter of a pound of anchovies, two ounces of shallots, and an ounce of ground black pepper.
# Boil up together for half an hour, strain through a sieve, and put to it the following spices; a quarter of an ounce of mace, the same of allspice and ginger, half an ounce of nutmeg, a drachm of coriander seed, and half a drachm of cochineal
The cochineal ( , ; ''Dactylopius coccus'') is a scale insect in the suborder Sternorrhyncha, from which the natural dye carmine is derived. A primarily sessility (motility), sessile parasitism, parasite native to tropical and subtropical Sout ...
.
# Pound all together; let them simmer gently for twenty minutes, and strain through a bag: when cold, bottle it, adding to each bottle a wineglass of brandy. It will keep for seven years.
In 1824, a ketchup recipe using tomatoes appeared in ''The Virginia Housewife'' (an influential 19th-century cookbook written by Mary Randolph,
Thomas Jefferson
Thomas Jefferson (, 1743July 4, 1826) was an American Founding Fathers of the United States, Founding Father and the third president of the United States from 1801 to 1809. He was the primary author of the United States Declaration of Indepe ...
's cousin). Tomato ketchup was sold locally by farmers. Jonas Yerkes is credited as the first American to sell it in a bottle. By 1837, he had produced and distributed the condiment nationally. By the mid-1850s, anchovies no longer featured as an ingredient.
Shortly thereafter, other companies followed suit.
F. & J. Heinz launched their tomato ketchup in 1876. American cooks also began to sweeten ketchup in the 19th century. The ''
Webster's Dictionary
''Webster's Dictionary'' is any of the US English language dictionaries edited in the early 19th century by Noah Webster (1758–1843), a US lexicographer, as well as numerous related or unrelated dictionaries that have adopted the Webster's n ...
'' of 1913 defined "catsup" as: "table sauce made from mushrooms, tomatoes, walnuts, etc.
lso written as ketchup" As the century progressed, tomato ketchup began its ascent in popularity in the United States. Tomato ketchup was popular long before fresh tomatoes were. People were less hesitant to eat tomatoes as part of a highly processed product that had been cooked and infused with vinegar and spices.
Heinz Tomato Ketchup was advertised: "Blessed relief for Mother and the other women in the household!", a slogan which alluded to the lengthy process required to produce tomato ketchup in the home.
With industrial ketchup production and a need for better preservation there was a great increase of sugar in ketchup, leading to the typically sweet and sour formula of today.
In Australia, it was not until the late 19th century that sugar was added to ''tomato sauce'', initially in small quantities, but today it contains just as much as American ketchup and only differed in the proportions of tomatoes, salt and vinegar in early recipes. While ketchup and tomato sauce are both sold in Australia, American ketchup is sweeter and thicker whereas Australian tomato sauce is more sour and runny.
Modern ketchup emerged in the early years of the 20th century, out of a debate over the use of
sodium benzoate as a preservative in condiments.
Harvey W. Wiley, the "father" of the
US Food and Drug Administration, challenged the safety of benzoate which was banned in the 1906
Pure Food and Drug Act
The s:Pure Food and Drug Act of 1906, Pure Food and Drug Act of 1906, also known as the Wiley Act and Harvey Washington Wiley, Dr. Wiley's Law, was the first of a series of significant consumer protection laws enacted by the United States Con ...
.
In response, entrepreneurs including
Henry J. Heinz, pursued an alternative recipe that eliminated the need for that preservative.
Katherine Bitting, a bacteriologist working for the U.S. Department of Agriculture, carried out research in 1909 that proved increasing the sugar and vinegar content of the product would prevent spoilage without use of artificial preservatives. She was assisted by her husband, Arvil Bitting, an official at that agency.
Prior to Heinz (and his fellow innovators), commercial tomato ketchups of that time were watery and thin, in part because they used unripe tomatoes, which were low in
pectin. They had less vinegar than modern ketchups; by
pickling
Pickling is the process of food preservation, preserving or extending the shelf life of food by either Anaerobic organism, anaerobic fermentation (food), fermentation in brine or immersion in vinegar. The pickling procedure typically affects t ...
ripe tomatoes, the need for benzoate was eliminated without spoilage or degradation in flavor. But the changes driven by the desire to eliminate benzoate also produced changes that some experts (such as Andrew F. Smith) believe were key to the establishment of tomato ketchup as the dominant American condiment.
Later innovations
In fast food outlets, ketchup is often dispensed in small sachets or tubs. Diners tear the side or top of
ketchup packets and squeeze ketchup out of them or peel the foil lid off tubs for dipping. In 2011, Heinz began offering a new measured-portion package, called the
"Dip and Squeeze" packet, which can be opened in either way.
Some fast food outlets previously dispensed ketchup from hand-operated pumps into paper cups. This method has made a comeback in the first decades of the 21st century, as cost and environmental concerns over the increasing use of individual plastic ketchup tubs were taken into account.
In October 2000, Heinz introduced colored ketchup products called EZ Squirt, which eventually included green (2000), purple (2001), mystery (pink, orange, or
teal, 2002), and blue (2003). These products were made by adding
food coloring
Food coloring, color additive or colorant is any dye, pigment, or substance that imparts color when it is added to food or beverages. Colorants can be supplied as liquids, powders, gels, or pastes. Food coloring is commonly used in commercia ...
to the traditional ketchup. By January 2006, these products were discontinued.
Terminology
The term used for the sauce varies. ''Ketchup'' is the dominant term in
American English
American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...
and
Canadian English
Canadian English (CanE, CE, en-CA) encompasses the Variety (linguistics), varieties of English language, English used in Canada. According to the 2016 Canadian Census, 2016 census, English was the first language of 19.4 million Canadians or ...
, although ''catsup'' is commonly used in some southern US states and
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
.
In Canada and the US, ''
tomato sauce
Tomato sauce (; ; ) can refer to many different sauces made primarily from tomatoes. In some countries the term refers to a sauce to be served as part of a dish, in others it is a condiment.
Tomatoes have a rich flavor, high water content, s ...
'' is not a synonym for ketchup but is a sauce made from tomatoes and commonly used in making sauce for pasta.
Etymology
The etymology of the word ''ketchup'' is unclear; there are multiple competing theories:
Amoy theory
A popular
folk etymology
Folk etymology – also known as (generative) popular etymology, analogical reformation, (morphological) reanalysis and etymological reinterpretation – is a change in a word or phrase resulting from the replacement of an unfamiliar form by a mo ...
is that the word came from the
Amoy (Xiamen) region of
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
into English, as a
borrowed word 茄汁 (,
Cantonese
Cantonese is the traditional prestige variety of Yue Chinese, a Sinitic language belonging to the Sino-Tibetan language family. It originated in the city of Guangzhou (formerly known as Canton) and its surrounding Pearl River Delta. While th ...
, meaning "tomato sauce"; the character means 'eggplant'; ''tomato'' in Chinese is , so the phrase literally translates to ''foreign eggplant sauce'').
Another theory among academics is that the word derives from one of two words from
Hokkien
Hokkien ( , ) is a Varieties of Chinese, variety of the Southern Min group of Chinese language, Chinese languages. Native to and originating from the Minnan region in the southeastern part of Fujian in southeastern China, it is also referred ...
of the
Fujian
Fujian is a provinces of China, province in East China, southeastern China. Fujian is bordered by Zhejiang to the north, Jiangxi to the west, Guangdong to the south, and the Taiwan Strait to the east. Its capital is Fuzhou and its largest prefe ...
region of coastal southern China:
''kôe-chiap'' (in the
Amoy / Xiamen dialect and
Quanzhou dialect
The Quanzhou dialects ( zh, s=泉州话, t=泉州話, poj=Choân-chiu-ōe), also rendered Chin-chew or Choanchew, are a collection of Hokkien dialects spoken in southern Fujian (in southeast China), in the area centered on the city of Quanzhou. ...
) or
''kê-chiap'' (in the Zhangzhou dialect
The Zhangzhou dialects (), also rendered Changchew, Chiangchew or Changchow, are a collection of Hokkien dialects spoken in southern Fujian province (in southeast China), centered on the city of Zhangzhou. The Zhangzhou dialect proper is the sou ...
). Both of these pronunciations of the same word (, / ) come from the Quanzhou dialect
The Quanzhou dialects ( zh, s=泉州话, t=泉州話, poj=Choân-chiu-ōe), also rendered Chin-chew or Choanchew, are a collection of Hokkien dialects spoken in southern Fujian (in southeast China), in the area centered on the city of Quanzhou. ...
, Amoy dialect
The Amoy dialect or Xiamen dialect (), also known as Amoyese, Amoynese, Amoy Hokkien, Xiamenese or Xiamen Hokkien, is a dialect of Hokkien spoken in the city of Xiamen (historically known as "Amoy") and its surrounding metropolitan area, in the ...
, and Zhangzhou dialect
The Zhangzhou dialects (), also rendered Changchew, Chiangchew or Changchow, are a collection of Hokkien dialects spoken in southern Fujian province (in southeast China), centered on the city of Zhangzhou. The Zhangzhou dialect proper is the sou ...
of Hokkien, respectively, where it meant the brine of pickled fish or shellfish (, 'pickled food' (usually seafood) + , 'juice'). There are citations of in the ''Chinese-English Dictionary of the Vernacular or Spoken Language of Amoy
Xiamen,), also known as Amoy ( ; from the Zhangzhou Hokkien pronunciation, zh, c=, s=, t=, p=, poj=Ē͘-mûi, historically romanized as Amoy, is a sub-provincial city in southeastern Fujian, People's Republic of China, beside the Taiwan Stra ...
'' (1873) by Carstairs Douglas, defined as "brine of pickled fish or shell-fish."
Malay theory
''Ketchup'' may have entered the English language from the Malay word (, sometimes spelled or ). Originally meaning "soy sauce", the word itself derives from Chinese.
In Indonesian cuisine
Indonesian cuisine is a collection of various regional culinary traditions by various ethnic groups that formed in the archipelagic nation of Indonesia. There are a wide variety of recipes and cuisines in part because Indonesia is composed ...
, which is similar to Malay, the term refers to fermented savory sauces. Two main types are well known in their cuisine: , which translates to "salty " in Indonesian (a salty soy sauce) and or "sweet " in Indonesian. is a sweet soy sauce that is a mixture of soy sauce with brown sugar, molasses, garlic, ginger, anise, coriander and a bay leaf reduced over medium heat until rather syrupy. A third type, , meaning "fish " is fish sauce
Fish sauce is a liquid condiment made from fish or krill that have been coated in salt and fermented for up to two years. It is used as a staple seasoning in East Asian cuisine and Southeast Asian cuisine, particularly Myanmar, Cambodia, L ...
similar to the Thai '' nam pla'' or the Philippine '' patis''. It is not, however, soy-based.
European-Arabic theory
American anthropologist E. N. Anderson relies on Elizabeth David to claim that ''ketchup'' is a cognate
In historical linguistics, cognates or lexical cognates are sets of words that have been inherited in direct descent from an etymological ancestor in a common parent language.
Because language change can have radical effects on both the s ...
of the French , meaning "food in sauce". The word also exists in Spanish and Portuguese forms as '' escabeche'', "a sauce for pickling", which culinary historian Karen Hess traced back to Arabic , or "pickling with vinegar". The term was anglicized to ''caveach'', a word first attested in the late 17th century, at the same time as ''ketchup''.
Early uses in English
The word entered the English language
English is a West Germanic language that developed in early medieval England and has since become a English as a lingua franca, global lingua franca. The namesake of the language is the Angles (tribe), Angles, one of the Germanic peoples th ...
in Britain during the late 17th century, appearing in print as ''catchup'' (1690) and later as ''ketchup'' (1711). The following is a list of early quotations collected by the ''Oxford English Dictionary
The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary of the English language, published by Oxford University Press (OUP), a University of Oxford publishing house. The dictionary, which published its first editio ...
''.
* 1690, B. E., '' A New Dictionary of the Terms Ancient and Modern of the Canting Crew''
** "Catchup: a high East-India Sauce."
* 1711, Charles Lockyer, ''An Account of the Trade in India'' 128
** "Soy comes in Tubbs from Japan, and the best Ketchup from Tonquin; yet good of both sorts are made and sold very cheap in China."
* 1727, Eliza Smith, '' The Compleat Housewife, or, Accomplish'd Gentlewoman's Companion''
** The first published recipe: it included mushrooms, anchovies and horseradish.
* 1730, Jonathan Swift
Jonathan Swift (30 November 1667 – 19 October 1745) was an Anglo-Irish writer, essayist, satirist, and Anglican cleric. In 1713, he became the Dean (Christianity), dean of St Patrick's Cathedral, Dublin, and was given the sobriquet "Dean Swi ...
, ''A Panegyrick on the Dean'' Wks. 1755 IV. I. 142
** "And, for our home-bred British cheer, Botargo, catsup, and caveer."
* 1748, Sarah Harrison, ''The Housekeeper's Pocket-Book and Compleat Family Cook''. i. (ed. 4) 2,
** "I therefore advise you to lay in a Store of Spices, ... neither ought you to be without ... Kitchup, or Mushroom Juice."
* 1751, Mrs. Hannah Glasse, ''Cookery Bk''. 309
** "It will taste like foreign Catchup."
* 1817, Lord Byron
George Gordon Byron, 6th Baron Byron (22 January 1788 – 19 April 1824) was an English poet. He is one of the major figures of the Romantic movement, and is regarded as being among the greatest poets of the United Kingdom. Among his best-kno ...
, '' Beppo'' viii,
** "Walk or ride to the Strand, and buy in gross ... Ketchup, Soy, Chili-vinegar, and Harvey ..."
* 1832, ''Vegetable Substances Used for the Food of Man'' 333
** "One ... application of mushrooms is ... converting them into the sauce called Catsup."
* 1840, Charles Dickens
Charles John Huffam Dickens (; 7 February 1812 – 9 June 1870) was an English novelist, journalist, short story writer and Social criticism, social critic. He created some of literature's best-known fictional characters, and is regarded by ...
, '' Barnaby Rudge'' (1849) 91/1
** "Some lamb chops (breaded, with plenty of ketchup)."
* 1845, Eliza Acton, ''Modern Cookery'' v. (1850) 136 (L.)
** "Walnut catsup."
* 1862, ''Macmillan's Magazine''. Oct. 466
** "He found in mothery catsup a number of yellowish globular bodies."
* 1874, Mordecai C. Cooke, ''Fungi; Their Nature, Influence and Uses'' 89
** "One important use to which several ... fungi can be applied, is the manufacture of ketchup."
Composition
U.S. Heinz tomato ketchup's ingredients (listed from highest to lowest percentage weight) are: tomato concentrate from red ripe tomatoes, distilled vinegar, high-fructose corn syrup, corn syrup
Corn syrup is a food syrup that is made from the starch of corn/maize and contains varying amounts of sugars: glucose, maltose and higher oligosaccharides, depending on the grade. Corn syrup is used in foods to soften Mouthfeel, texture, add vol ...
, salt
In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...
, spice, onion powder, and natural flavoring.
"Fancy" ketchup
Some ketchup in the U.S. is labeled "Fancy", a USDA
The United States Department of Agriculture (USDA) is an United States federal executive departments, executive department of the Federal government of the United States, United States federal government that aims to meet the needs of commerc ...
grade related to specific gravity
Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nea ...
. Fancy ketchup has a higher tomato solid concentration than other USDA grades.
Nutrition
The following table compares the nutritional value of ketchup with raw ripe tomatoes and salsa, based on information from the USDA
The United States Department of Agriculture (USDA) is an United States federal executive departments, executive department of the Federal government of the United States, United States federal government that aims to meet the needs of commerc ...
Food Nutrient Database.
Viscosity
Commercial tomato ketchup has an additive, usually xanthan gum, which gives the condiment a non-Newtonian, pseudoplastic
In rheology, shear thinning is the non-Newtonian behavior of fluids whose viscosity decreases under shear strain. It is sometimes considered synonymous for pseudo-plastic behaviour, and is usually defined as excluding time-dependent effects, ...
or "shear thinning" property—more commonly known as thixotropy. This increases the viscosity of the ketchup considerably with a relatively small amount added—usually 0.5%—which can make it difficult to pour from a container. However, the shear thinning property of the gum ensures that when a force is applied to the ketchup, it will lower the viscosity, enabling the sauce to flow. A common method of getting ketchup out of the bottle involves inverting the bottle and shaking it or hitting the bottom with the heel of the hand, which causes the ketchup to flow rapidly. Ketchup in plastic bottles can be additionally manipulated by squeezing the bottle, which also decreases the viscosity of the ketchup inside. Another technique involves inverting the bottle and forcefully tapping its upper neck with two fingers (index and middle finger together). Specifically, with a Heinz ketchup glass bottle, one taps the 57 circle on the neck. This helps the ketchup flow by applying the correct shearing force. These techniques work because of how pseudoplastic fluids behave: their viscosity
Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...
(resistance to flow) decreases with increasing shear rate. The faster the ketchup is sheared (by shaking or tapping the bottle), the more fluid it becomes. After the shear is removed, the ketchup thickens to its original viscosity.
Ketchup is a non-Newtonian fluid, meaning that its viscosity changes under stress and is not constant. It is a shear thinning fluid, which means its viscosity decreases with increased shear stress. The equation used to designate a non-Newtonian fluid is as follows: . This equation represents apparent viscosity where apparent viscosity is the shear stress
Shear stress (often denoted by , Greek alphabet, Greek: tau) is the component of stress (physics), stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross secti ...
divided by shear rate. Viscosity is dependent on stress. This is apparent when one shakes a bottle of ketchup so it becomes liquid enough to squirt out. Its viscosity decreases with stress.
The molecular composition of ketchup is what creates its pseudoplastic
In rheology, shear thinning is the non-Newtonian behavior of fluids whose viscosity decreases under shear strain. It is sometimes considered synonymous for pseudo-plastic behaviour, and is usually defined as excluding time-dependent effects, ...
characteristics. Small polysaccharides, sugars, acids, and water make up the majority of the metastable ketchup product, and these small structures are able to move more easily throughout a matrix because of their low mass. While exposed to shear stress, the molecules within the suspension are able to respond quickly and create an alignment within the product. The bonds between the molecules are mostly hydrogen bonds, ionic interactions, and electrostatic interactions, all of which can be broken when subject to stress. Hydrogen bond
In chemistry, a hydrogen bond (H-bond) is a specific type of molecular interaction that exhibits partial covalent character and cannot be described as a purely electrostatic force. It occurs when a hydrogen (H) atom, Covalent bond, covalently b ...
s are constantly rearranging within a product due to their need to be in the lowest energy state, which further confirms that the bonds between the molecules will be easily disrupted. This alignment only lasts for as long as shear stress is applied. The molecules return to their original disorganized state once the shear stress dissipates.
In 2017, researchers at the Massachusetts Institute of Technology
The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...
reported the development of a bottle coating that allowed all the product to slip out without leaving a residue.
In 2022, researchers at the University of Oxford
The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...
found that splatter from a near-empty bottle can be prevented by squeezing more slowly and doubling the diameter of the nozzle.
Separation
Ketchup is one of the many products that are leachable, meaning that the water within the product migrates together as the larger molecules within the product sediment, ultimately causing water to separate out. This forms a layer of water on top of the ketchup due to the molecular instability within the product. This instability is caused by interactions between hydrophobic molecules and charged molecules within the ketchup suspension.
Pectin is a polysaccharide within tomatoes that has the ability to bind to itself and to other molecules, especially water, around it. This enables it to create a gel-like matrix, dependent on the amount within the solution. Water is a large part of ketchup, due to it being 80% of the composition of distilled vinegar. In order for the water within the ketchup to be at the lowest possible energy state, all of the hydrogen bonds that are able to be made within the matrix must be made. The water bound to the polysaccharide moves more slowly within the matrix, which is unfavorable with respect to entropy
Entropy is a scientific concept, most commonly associated with states of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the micros ...
. The increased order within the polysaccharide-water complex gives rise to a high-energy state, in which the water will want to be relieved. This concept implies that water will more favorably bind with itself because of the increased disorder between water molecules. This is partially the cause for water leaching out of solution when left undisturbed for a short period of time.
See also
*
* Ketchups:
** Banana ketchup
** Curry ketchup
** Fruit ketchup
*
* List of dips
* List of condiments
A condiment is a supplemental food (such as a sauce or powder) that is added to some foods to impart a particular flavor, enhance their flavor, or, in some cultures, to complement the dish, but that cannot stand alone as a dish. The term ''cond ...
** Mustard
* Shelf stable food
*
* Tomato preparations:
** Tomato jam
** Tomato paste
** Tomato purée
** Tomato sauce
Tomato sauce (; ; ) can refer to many different sauces made primarily from tomatoes. In some countries the term refers to a sauce to be served as part of a dish, in others it is a condiment.
Tomatoes have a rich flavor, high water content, s ...
** More: List of tomato dishes
This list includes dishes in which the main ingredient or one of the essential ingredients is tomato. Dishes prepared with tomato sauces as a primary ingredient are not included in this list.
Tomato dishes
*
*
*
*
*
**
*
*
*
*
*
*
...
Notes
References
Further reading
* On the origin of the 9 g ketchup packet.
External links
*
{{Authority control
Condiments
Sauces
Non-Newtonian fluids
Australian condiments