
Ketchup

Ketchup is a table condiment. The unmodified term ("ketchup") now typically refers to tomato ketchup, although original recipes used egg whites, mushrooms, oysters, grapes, mussels, or walnuts, among other ingredients. 
Tomato ketchup is a sweet and tangy condiment made from tomatoes, sugar, and vinegar, with seasonings and spices. The spices and flavors vary, but commonly include onions, allspice, coriander, cloves, cumin, garlic, and mustard, and sometimes include celery, cinnamon, or ginger. The market leader in the United States (60% market share) and the United Kingdom (82%) is Heinz Tomato Ketchup. Tomato ketchup is most often used as a condiment to dishes that are usually served hot and may be fried or greasy: french fries and other potatoes, hamburgers, hot dogs, chicken tenders, tater tots, hot sandwiches, 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 chips.
History.
Mushroom ketchup.
In the United Kingdom, preparations of ketchup were historically and originally prepared with mushrooms as a primary ingredient, rather than tomatoes. Ketchup recipes began to appear in British and then American cookbooks in the 18th century. In a 1742 London cookbook, the fish sauce had already taken on a very British flavor, with the addition of shallots and mushrooms. The mushrooms soon became the main ingredient and from 1750 to 1850 the word "ketchup" began to mean any number of thin dark sauces made of mushrooms or even walnuts. In the United States, mushroom ketchup dates back to at least 1770, and was prepared by British colonists in the Thirteen Colonies. In contemporary times, mushroom ketchup is available in the UK, although it is not a commonly used condiment.
Tomato ketchup.
Many variations of ketchup were created, but the tomato-based version did not appear until about a century after other types. An early recipe for "Tomata Catsup" from 1817 includes anchovies and states:
By the mid-1850s, the anchovies had been dropped.
James Mease published another recipe in 1812. In 1824, a ketchup recipe using tomatoes appeared in "The Virginia Housewife" (an influential 19th-century cookbook written by Mary Randolph, Thomas Jefferson's cousin). American cooks also began to sweeten ketchup in the 19th century.
As the century progressed, tomato ketchup began its ascent in popularity in the United States. 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. 
Tomato ketchup was sold locally by farmers. Jonas Yerkes is credited as the first American to sell tomato ketchup in a bottle. By 1837, he had produced and distributed the condiment nationally. Shortly thereafter, other companies followed suit. F. & J. Heinz launched their tomato ketchup in 1876. 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 our modern sweet and sour formula. In Australia, it wasn't 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.
The "Webster's Dictionary" of 1913 defined "Catsup" as: "table sauce made from mushrooms, tomatoes, walnuts, etc. [Also written as ketchup]."
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 Food and Drug Administration in the US, challenged the safety of benzoate which was banned in the 1906 Pure Food and Drug Act.
In response, entrepreneurs including Henry J. Heinz, pursued an alternative recipe that eliminated the need for that preservative. Katherine Bitting, a microbotanist working for the U.S. Department of Agriculture, carried out research that proved in 1909 that 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 due to the use of unripe tomatoes, which were low in pectin. They had less vinegar than modern ketchups; by pickling 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 and squeeze the ketchup out of the ketchup packets, or peel the foil lid off the tub 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, giving both options.
Some fast food outlets previously dispensed ketchup from hand-operated pumps into paper cups. This method has made a comeback in the first decade 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 to the traditional ketchup. these products were discontinued.
In March 2018 a kickstarter campaign was launched for sliced ketchup. Reception has been polarized, where Time news cited reviews negatively declaring it "a crime", and positively as "revolutionizing the way we sauce".
Terminology.
The term used for the sauce varies. "Ketchup" is the dominant term in American English and Canadian English, although "catsup" is commonly used in some southern US states and Mexico.
"Tomato sauce" is more common in English-speaking countries outside North America. In Canada and the US "tomato sauce" is not a synonym for ketchup but a sauce made from tomatoes and commonly eaten with pasta.
"Red sauce" is the term used in Welsh English, Scottish English, Ulster English and some parts of England, such as the Black Country, and in South London, contrasting with brown sauce. In Canadian and American English, "red sauce" refers to various tomato-based sauces like marinara commonly paired with pasta dishes, or in southwestern regions refers to red chile sauces used with tamales, enchiladas, and similar dishes, and is not a synonym for ketchup.
Etymology.
The etymology of the word "ketchup" is unclear, with multiple competing theories:
Cantonese theory.
One theory is that the word came to English from the Cantonese "keh jup" (茄汁 "ke2 zap1", the word literally means "tomato sauce" in Cantonese). An alternative theory is that the word derives from one of two words from Hokkien of the Fujian region of coastal southern China: "kôe-chiap" (in Xiamen and Quanzhou) or "kê-chiap" (in Zhangzhou and Guangzhou). Both of these words (膎汁, kôe-chiap and kêchiap) come from either the Quanzhou dialect, Amoy dialect, or Zhangzhou dialect of Hokkien, where it meant the brine of pickled fish (膎, meat; 汁, juice) or shellfish. There are citations of "koe-chiap" in the "Dictionary of the Vernacular or Spoken Language of the Amoy" (London; Trudner) from 1873, defined as "brine of pickled fish or shell-fish".
Malay theory.
Ketchup may have entered the English language from the Malay word "kicap" (pron. "kichap", sometimes spelled "kecap" or "ketjap"). Originally meaning "fish sauce", the word itself derives from the Chinese terms.
In Indonesian cuisine, which is similar to Malay, the term "kecap" refers to fermented savory sauces. Two main types are well known in their cuisine: "kecap asin" which translates to 'salty kecap' in Indonesian (a salty soy sauce) and "kecap manis" or "sweet kecap" in Indonesian. Kecap manis 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, "kecap ikan", meaning "fish kecap" is fish sauce 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 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 "Kabees", 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 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".
Composition.
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, salt, spice, onion powder, and natural flavoring.
"Fancy" ketchup.
Some ketchup in the U.S. is labeled "Fancy". This is a USDA grade, relating to specific gravity. Fancy ketchup has a higher tomato solid concentration than other USDA grades.
Processing.
After sorting, washing, and chopping, tomatoes are placed into large steel vats for preservation and precooking. Tomato juice and pulp are separated by filtering and screening. Once separated, the juice is further processed into ketchup. Ketchup processing includes adding additional ingredients, cooking, more screening and filtering, air-removal, packaging and cooling. 
After juice filtration, additional ingredients are added to the mixture to achieve the desired taste and consistency. Throughout the entire process, the temperature must be constantly monitored to make sure all ingredients are properly mixed. Air is then removed to prevent oxidation, maintain proper coloring and inhibit the growth of any unwanted bacteria. Before being packaged, the ketchup is heated to approximately to prevent contamination. After packaging, the bottles are immediately sealed and cooled to preserve freshness and improve shelf-life of the product.
Nutrition.
The following table compares the nutritional value of ketchup with raw ripe tomatoes and salsa, based on information from the USDA Food Nutrient Database.
Viscosity.
Commercial tomato ketchup has an additive, usually xanthan gum, which gives the condiment a pseudoplastic or "shear thinning" property - more commonly known as thixotropic. 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 to 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. A 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 (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: formula_1. This equation represents apparent viscosity where apparent viscosity is the shear stress divided by shear rate. Viscosity is dependent on stress. This is apparent when you shake a bottle of tomato sauce/ketchup so it becomes liquid enough to squirt out. Its viscosity decreased with stress.
The molecular composition of ketchup is what creates ketchup's pseudoplastic 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 bonds 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 reported the development of a bottle coating that allowed all the product to slip out without leaving a residue.
Separation.
Ketchup is one of the many products that is 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. 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.
Other interactions that induce leaching are electrostatic and ionic interactions. Electrostatic interactions occur between charged molecules, which have repulsive or attractive forces between each other. The pectin within ketchup will have negative and neutral charges along the molecule due to the hydroxyl groups and relative pH, which is 3.65 on average. Pectin is most stable at a pH of 3.5, so the more basic pH within ketchup will protonate the hydroxyl side chains and therefore create a less viscous gel. Acetic acid within vinegar also has hydroxyl groups that will have a dispersed amount of negative and neutral charges along each molecule. The acetic acid and pectin will display repulsive interactions between the negatively charged oxygens on each molecule. The hydroxyls on each molecule will be able to form hydrogen bonds with the water in the product. The addition of salt will reduce the repulsive interactions between the negatively charged side chains of acetic acid and pectin within solution because they will create bonds with the dissociated sodium and chloride ions. The hydrogen bonds and electrostatic interactions will encourage leaching because the formation of bonds associated with the need for molecules to be in the lowest energy state are not always bonds that happen between different molecules and instead are formed between like molecules, causing aggregation.