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  • Sugar (Carbohydrates)

    Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucosefructose, and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two molecules of glucose). White sugar is a refined form of sucrose. In the body, compound sugars are hydrolysed into simple sugars.

    Longer chains of monosaccharides (>2) are not regarded as sugars and are called oligosaccharides or polysaccharidesStarch is a glucose polymer found in plants, the most abundant source of energy in human food. Some other chemical substances, such as ethylene glycolglycerol and sugar alcohols, may have a sweet taste but are not classified as sugar.

    Sugars are found in the tissues of most plants. Honey and fruits are abundant natural sources of simple sugars. Sucrose is especially concentrated in sugarcane and sugar beet, making them ideal for efficient commercial extraction to make refined sugar. In 2016, the combined world production of those two crops was about two billion tonnes. Maltose may be produced by malting grain. Lactose is the only sugar that cannot be extracted from plants. It can only be found in milk, including human breast milk, and in some dairy products. A cheap source of sugar is corn syrup, industrially produced by converting corn starch into sugars, such as maltose, fructose and glucose.

    Sucrose is used in prepared foods (e.g., cookies and cakes), is sometimes added to commercially available ultra-processed food and beverages, and is sometimes used as a sweetener for foods (e.g., toast and cereal) and beverages (e.g., coffee and tea). The average person consumes about 24 kilograms (53 pounds) of sugar each year. North and South Americans consume up to 50 kg (110 lb), and Africans consume under 20 kg (44 lb).[1]

    As free sugar consumption grew in the latter part of the 20th century, researchers began to examine whether a diet high in free sugar, especially refined sugar, was damaging to human health. In 2015, the World Health Organization strongly recommended that adults and children reduce their intake of free sugars to less than 10% of their total energy intake and encouraged a reduction to below 5%.[2] In general, high sugar consumption damages human health more than it provides nutritional benefit and is associated with a risk of cardiometabolic and other health detriments.[3]

    Etymology

    [edit]

    The etymology of sugar reflects the commodity’s spread. From Sanskrit śarkarā, meaning “ground or candied sugar”, came Persian shakar and Arabic sukkar. The Arabic word was borrowed in Medieval Latin as succarum, whence came the 12th century French sucre and the English sugar. Sugar was introduced into Europe by the Arabs in Sicily and Spain.[4]

    The English word jaggery, a coarse brown sugar made from date palm sap or sugarcane juice, has a similar etymological origin: Portuguese jágara from the Malayalam cakkarā, which is from the Sanskrit śarkarā.[5]

    History

    [edit]

    Main article: History of sugar

    Ancient world to Renaissance

    [edit]

    Sugar cane plantation

    Asia

    [edit]

    Sugar has been produced in the Indian subcontinent[6] for thousands of years. Sugarcane cultivation spread from there into China via the Khyber Pass and caravan routes.[7] It was not plentiful or cheap in early times, and in most parts of the world, honey was more often used for sweetening.[8] Originally, people chewed raw sugarcane to extract its sweetness. Even after refined sugarcane became more widely available during the European colonial era,[9] palm sugar was preferred in Java and other sugar producing parts of southeast Asia, and along with coconut sugar, is still used locally to make desserts today.[10][11]

    Sugarcane is native of tropical areas such as the Indian subcontinent (South Asia) and Southeast Asia.[6][12] Different species seem to have originated from different locations; Saccharum barberi originated in India, and S. edule and S. officinarum came from New Guinea.[12][13] One of the earliest historical references to sugarcane is in Chinese manuscripts dating to the 8th century BCE, which state that the use of sugarcane originated in India.[14]

    In the tradition of Indian medicine (āyurveda), sugarcane is known by the name Ikṣu, and sugarcane juice is known as Phāṇita. Its varieties, synonyms and characteristics are defined in nighaṇṭus such as the Bhāvaprakāśa (1.6.23, group of sugarcanes).[15]

    Sugar remained relatively unimportant until around 350 AD when the Indians discovered methods of turning sugarcane juice into granulated crystals that were easier to store and transport. It was then considered as ‘sweet spice’ and Indian traders started trading sugar outside India.[16] The Greek physician Pedanius Dioscorides attested to the method in his 1st century CE medical treatise De Materia Medica:

    There is a kind of coalesced honey called sakcharon [i.e. sugar] found in reeds in India and Eudaimon Arabia similar in consistency to salt and brittle enough to be broken between the teeth like salt,

    — Pedanius Dioscorides, Materia Medica, Book II[17][18]

    In the local Indian language, these crystals were called khanda (Devanagari: खण्ड, Khaṇḍa), which is the source of the word candy.[19] Indian sailors, who carried clarified butter and sugar as supplies, introduced knowledge of sugar along the various trade routes they travelled.[20] Traveling Buddhist monks took sugar crystallization methods to China.[21] During the reign of Harsha (r. 606–647) in North India, Indian envoys in Tang China taught methods of cultivating sugarcane after Emperor Taizong of Tang (r. 626–649) made known his interest in sugar. China established its first sugarcane plantations in the seventh century.[22] Chinese documents confirm at least two missions to India, initiated in 647 CE, to obtain technology for sugar refining.[23]

    Europe

    [edit]

    Two elaborate sugar triomfi of goddesses for a dinner given by the Earl of Castlemaine, British ambassador in Rome, 1687

    Nearchus, admiral of Alexander the Great, knew of sugar during the year 325 BC because of his participation in the campaign of India led by Alexander (ArrianAnabasis).[24][25] In addition to the Greek physician Pedanius Dioscorides, the Roman Pliny the Elder also described sugar in his 1st century CE Natural History: “Sugar is made in Arabia as well, but Indian sugar is better. It is a kind of honey found in cane, white as gum, and it crunches between the teeth. It comes in lumps the size of a hazelnut. Sugar is used only for medical purposes.[26] Crusaders brought sugar back to Europe after their campaigns in the Holy Land, where they encountered caravans carrying “sweet salt”. Early in the 12th century, the Republic of Venice acquired some villages near Tyre and set up estates to produce sugar for export to Europe. It supplemented the use of honey, which had previously been the only available sweetener.[27] Crusade chronicler William of Tyre, writing in the late 12th century, described sugar as “very necessary for the use and health of mankind”.[28] In the 15th century, Venice was the chief sugar refining and distribution center in Europe.[14]

    There was a drastic change in the mid-15th century, when Madeira and the Canary Islands were settled from Europe and sugar introduced there.[29][30] After this an “all-consuming passion for sugar … swept through society” as it became far more easily available, though initially still very expensive.[31] By 1492, Madeira was producing over 1,400,000 kilograms (3,000,000 lb) of sugar annually.[32] Genoa, one of the centers of distribution, became known for candied fruit, while Venice specialized in pastries, sweets (candies), and sugar sculptures. Sugar was considered to have “valuable medicinal properties” as a “warm” food under prevailing categories, being “helpful to the stomach, to cure cold diseases, and sooth lung complaints”.[33]

    A feast given in Tours in 1457 by Gaston de Foix, which is “probably the best and most complete account we have of a late medieval banquet” includes the first mention of sugar sculptures, as the final food brought in was “a heraldic menagerie sculpted in sugar: lions, stags, monkeys … each holding in paw or beak the arms of the Hungarian king“.[34] Other recorded grand feasts in the decades following included similar pieces.[35] Originally the sculptures seem to have been eaten in the meal, but later they become merely table decorations, the most elaborate called trionfi. Several significant sculptors are known to have produced them; in some cases their preliminary drawings survive. Early ones were in brown sugar, partly cast in molds, with the final touches carved. They continued to be used until at least the Coronation Banquet for Edward VII of the United Kingdom in 1903; among other sculptures every guest was given a sugar crown to take away.[36]

    Modern history

    [edit]

    See also: Triangular trade

    Sugar cane; demand for sugar contributed to creating colonial systems in areas where cultivation of sugar cane was profitable.

    Hacienda La Fortuna. A sugar mill complex in Puerto Rico, painted by Francisco Oller in 1885, Brooklyn Museum

    In August 1492, Christopher Columbus collected sugar cane samples in La Gomera in the Canary Islands, and introduced it to the New World.[37] The cuttings were planted and the first sugar-cane harvest in Hispaniola took place in 1501. Many sugar mills had been constructed in Cuba and Jamaica by the 1520s.[38] The Portuguese took sugar cane to Brazil. By 1540, there were 800 cane-sugar mills in Santa Catarina Island and another 2,000 on the north coast of Brazil, Demarara, and Surinam. It took until 1600 for Brazilian sugar production to exceed that of São Tomé, which was the main center of sugar production in sixteenth century.[30]

    German chemists Andreas Sigismund Marggraf (left) and Franz Karl Achard (right) both laid the foundation of the modern sugar industry.

    Sugar was a luxury in Europe until the early 19th century, when it became more widely available, due to the rise of beet sugar in Prussia, and later in France under Napoleon.[39] Beet sugar was a German invention, since, in 1747, Andreas Sigismund Marggraf announced the discovery of sugar in beets and devised a method using alcohol to extract it.[40] Marggraf’s student, Franz Karl Achard, devised an economical industrial method to extract the sugar in its pure form in the late 18th century.[41][42] Achard first produced beet sugar in 1783 in Kaulsdorf, and in 1801, the world’s first beet sugar production facility was established in CunernSilesia (then part of Prussia, now Poland).[43] The works of Marggraf and Achard were the starting point for the sugar industry in Europe,[44] and for the modern sugar industry in general, since sugar was no longer a luxury product and a product almost only produced in warmer climates.[45]

    Sugar became highly popular and by the 19th century, was found in every household. This evolution of taste and demand for sugar as an essential food ingredient resulted in major economic and social changes.[46] Demand drove, in part, the colonization of tropical islands and areas where labor-intensive sugarcane plantations and sugar manufacturing facilities could be successful.[46] World consumption increased more than 100 times from 1850 to 2000, led by Britain, where it increased from about 2 pounds per head per year in 1650 to 90 pounds by the early 20th century. In the late 18th century Britain consumed about half the sugar which reached Europe.[47]

    After slavery was abolished, the demand for workers in European colonies in the Caribbean was filled by indentured laborers from the Indian subcontinent.[48][49][50] Millions of enslaved or indentured laborers were brought to various European colonies in the Americas, Africa and Asia (as a result of demand in Europe for among other commodities, sugar), influencing the ethnic mixture of numerous nations around the globe.[51][52][53]

    Sugar also led to some industrialization of areas where sugar cane was grown. For example, in the 1790s Lieutenant J. Paterson, of the Bengal Presidency promoted to the British parliament the idea that sugar cane could grow in British India, where it had started, with many advantages and at less expense than in the West Indies. As a result, sugar factories were established in Bihar in eastern India.[54][55] During the Napoleonic Wars, sugar-beet production increased in continental Europe because of the difficulty of importing sugar when shipping was subject to blockade. By 1880 the sugar beet was the main source of sugar in Europe. It was also cultivated in Lincolnshire and other parts of England, although the United Kingdom continued to import the main part of its sugar from its colonies.[56]

    Until the late nineteenth century, sugar was purchased in loaves, which had to be cut using implements called sugar nips.[57] In later years, granulated sugar was more usually sold in bags. Sugar cubes were produced in the nineteenth century. The first inventor of a process to produce sugar in cube form was Jakob Christof Rad, director of a sugar refinery in Dačice. In 1841, he produced the first sugar cube in the world.[58] He began sugar-cube production after being granted a five-year patent for the process on 23 January 1843. Henry Tate of Tate & Lyle was another early manufacturer of sugar cubes at his refineries in Liverpool and London. Tate purchased a patent for sugar-cube manufacture from German Eugen Langen, who in 1872 had invented a different method of processing of sugar cubes.[59]

    Sugar was rationed during World War I, though it was said that “No previous war in history has been fought so largely on sugar and so little on alcohol”,[60] and more sharply during World War II.[61][62][63][64][65] Rationing led to the development and use of various artificial sweeteners.[61][66]

    Chemistry

    [edit]

    Sucrose: a disaccharide of glucose (left) and fructose (right)

    Scientifically, sugar loosely refers to a number of carbohydrates, such as monosaccharidesdisaccharides, or oligosaccharides. Monosaccharides are also called “simple sugars”, the most important being glucose. Most monosaccharides have a formula that conforms to C
    nH
    2nO
    n with n between 3 and 7 (deoxyribose being an exception). Glucose has the molecular formula C
    6H
    12O
    6. The names of typical sugars end with –ose, as in “glucose” and “fructose“. Sometimes such words may also refer to any types of carbohydrates soluble in water. The acyclic mono- and disaccharides contain either aldehyde groups or ketone groups. These carbon-oxygen double bonds (C=O) are the reactive centers. All saccharides with more than one ring in their structure result from two or more monosaccharides joined by glycosidic bonds with the resultant loss of a molecule of water (H
    2O) per bond.[67]

    Monosaccharides in a closed-chain form can form glycosidic bonds with other monosaccharides, creating disaccharides (such as sucrose) and polysaccharides (such as starch or cellulose). Enzymes must hydrolyze or otherwise break these glycosidic bonds before such compounds become metabolized. After digestion and absorption the principal monosaccharides present in the blood and internal tissues include glucose, fructose, and galactose. Many pentoses and hexoses can form ring structures. In these closed-chain forms, the aldehyde or ketone group remains non-free, so many of the reactions typical of these groups cannot occur. Glucose in solution exists mostly in the ring form at equilibrium, with less than 0.1% of the molecules in the open-chain form.[67]

    Natural polymers

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    Biopolymers of sugars are common in nature. Through photosynthesis, plants produce glyceraldehyde-3-phosphate (G3P), a phosphated 3-carbon sugar that is used by the cell to make monosaccharides such as glucose (C
    6H
    12O
    6) or (as in cane and beet) sucrose (C
    12H
    22O
    11). Monosaccharides may be further converted into structural polysaccharides such as cellulose and pectin for cell wall construction or into energy reserves in the form of storage polysaccharides such as starch or inulin. Starch, consisting of two different polymers of glucose, is a readily degradable form of chemical energy stored by cells, and can be converted to other types of energy.[67] Another polymer of glucose is cellulose, which is a linear chain composed of several hundred or thousand glucose units. It is used by plants as a structural component in their cell walls. Humans can digest cellulose only to a very limited extent, though ruminants can do so with the help of symbiotic bacteria in their gut.[68] DNA and RNA are built up of the monosaccharides deoxyribose and ribose, respectively. Deoxyribose has the formula C
    5H
    10O
    4 and ribose the formula C
    5H
    10O
    5.[69]

    Flammability and heat response

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    Magnification of grains of refined sucrose, the most common free sugar

    Because sugars burn easily when exposed to flame, the handling of sugars risks dust explosion. The risk of explosion is higher when the sugar has been milled to superfine texture, such as for use in chewing gum.[70] The 2008 Georgia sugar refinery explosion, which killed 14 people and injured 36, and destroyed most of the refinery, was caused by the ignition of sugar dust.[71]

    In its culinary use, exposing sugar to heat causes caramelization. As the process occurs, volatile chemicals such as diacetyl are released, producing the characteristic caramel flavor.[72]

    Types

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    Monosaccharides

    [edit]

    Fructose, galactose, and glucose are all simple sugars, monosaccharides, with the general formula C6H12O6. They have five hydroxyl groups (−OH) and a carbonyl group (C=O) and are cyclic when dissolved in water. They each exist as several isomers with dextro- and laevo-rotatory forms that cause polarized light to diverge to the right or the left.[73]

    • Fructose, or fruit sugar, occurs naturally in fruits, some root vegetables, cane sugar and honey and is the sweetest of the sugars. It is one of the components of sucrose or table sugar. It is used as a high-fructose syrup, which is manufactured from hydrolyzed corn starch that has been processed to yield corn syrup, with enzymes then added to convert part of the glucose into fructose.[74]
    • Galactose generally does not occur in the free state but is a constituent with glucose of the disaccharide lactose or milk sugar. It is less sweet than glucose. It is a component of the antigens found on the surface of red blood cells that determine blood groups.[75]
    • Glucose occurs naturally in fruits and plant juices and is the primary product of photosynthesisStarch is converted into glucose during digestion, and glucose is the form of sugar that is transported around the bodies of animals in the bloodstream. Although in principle there are two enantiomers of glucose (mirror images one of the other), naturally occurring glucose is D-glucose. This is also called dextrose, or grape sugar because drying grape juice produces crystals of dextrose that can be sieved from the other components.[76] Glucose syrup is a liquid form of glucose that is widely used in the manufacture of foodstuffs. It can be manufactured from starch by enzymatic hydrolysis.[77] For example, corn syrup, which is produced commercially by breaking down maize starch, is one common source of purified dextrose.[78] However, dextrose is naturally present in many unprocessed, whole foods, including honey and fruits such as grapes.[79]

    Disaccharides

    [edit]

    Lactose, maltose, and sucrose are all compound sugars, disaccharides, with the general formula C12H22O11. They are formed by the combination of two monosaccharide molecules with the exclusion of a molecule of water.[73]

    • Lactose is the naturally occurring sugar found in milk. A molecule of lactose is formed by the combination of a molecule of galactose with a molecule of glucose. It is broken down when consumed into its constituent parts by the enzyme lactase during digestion. Children have this enzyme but some adults no longer form it and they are unable to digest lactose.[80]
    • Maltose is formed during the germination of certain grains, the most notable being barley, which is converted into malt, the source of the sugar’s name. A molecule of maltose is formed by the combination of two molecules of glucose. It is less sweet than glucose, fructose or sucrose.[73] It is formed in the body during the digestion of starch by the enzyme amylase and is itself broken down during digestion by the enzyme maltase.[81]
    • Sucrose is found in the stems of sugarcane and roots of sugar beet. It also occurs naturally alongside fructose and glucose in other plants, in particular fruits and some roots such as carrots. The different proportions of sugars found in these foods determines the range of sweetness experienced when eating them.[73] A molecule of sucrose is formed by the combination of a molecule of glucose with a molecule of fructose. After being eaten, sucrose is split into its constituent parts during digestion by a number of enzymes known as sucrases.[82]

    Sources

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    The sugar contents of common fruits and vegetables are presented in Table 1.

    Food itemTotal
    carbohydrateA
    including
    dietary fiber
    Total
    sugars
    Free
    fructose
    Free
    glucose
    SucroseFructose/
    (Fructose+Glucose)
    ratioB
    Sucrose
    as a % of
    total sugars
    Fruits       
    Apple13.810.45.92.42.10.6720
    Apricot11.19.20.92.45.90.4264
    Banana22.812.24.95.02.40.520
    Fig, dried63.947.922.924.80.90.481.9
    Grapes18.115.58.17.20.20.531
    Navel orange12.58.52.252.04.30.5151
    Peach9.58.41.52.04.80.4757
    Pear15.59.86.22.80.80.678
    Pineapple13.19.92.11.76.00.5261
    Plum11.49.93.15.11.60.4016
    Strawberry7.684.892.4411.990.470.5510
    Vegetables       
    Beet, red9.66.80.10.16.50.5096
    Carrot9.64.70.60.63.60.5077
    Corn, sweet19.06.21.93.40.90.3815
    Red pepper, sweet6.04.22.31.90.00.550
    Onion, sweet7.65.02.02.30.70.4714
    Sweet potato20.14.20.71.02.50.4760
    Yam27.90.5trtrtrnatr
    Sugar cane13–180.2–1.00.2–1.011–160.50high
    Sugar beet17–180.1–0.50.1–0.516–170.50high

    ^A The carbohydrate figure is calculated in the USDA database and does not always correspond to the sum of the sugars, the starch, and the dietary fiber.[why?]^B The fructose to fructose plus glucose ratio is calculated by including the fructose and glucose coming from the sucrose.

    Production

    [edit]

    See also: List of sugars

    Due to rising demand, sugar production in general increased some 14% over the period 2009 to 2018.[84] The largest importers were China, Indonesia, and the United States.[84]

    Sugar

    [edit]

    In 2022–2023 world production of sugar was 186 million tonnes, and in 2023–2024 an estimated 194 million tonnes — a surplus of 5 million tonnes, according to Ragus.[85]

    Sugarcane

    [edit]

    Sugarcane production – 2022
    CountryMillions of tonnes
     Brazil724.4
     India439.4
     China103.4
     Thailand92.1
    World1,922.1
    Source: FAO[86]

    Sugar cane accounted for around 21% of the global crop production over the 2000–2021 period. The Americas was the leading region in the production of sugar cane (52% of the world total).[87] Global production of sugarcane in 2022 was 1.9 billion tonnes, with Brazil producing 38% of the world total and India 23% (table).

    Sugarcane is any of several species, or their hybrids, of giant grasses in the genus Saccharum in the family Poaceae. They have been cultivated in tropical climates in the Indian subcontinent and Southeast Asia over centuries for the sucrose found in their stems.[6]

    World production of raw sugar, main producers[88]

    Sugar cane requires a frost-free climate with sufficient rainfall during the growing season to make full use of the plant’s substantial growth potential. The crop is harvested mechanically or by hand, chopped into lengths and conveyed rapidly to the processing plant (commonly known as a sugar mill) where it is either milled and the juice extracted with water or extracted by diffusion.[89] The juice is clarified with lime and heated to destroy enzymes. The resulting thin syrup is concentrated in a series of evaporators, after which further water is removed. The resulting supersaturated solution is seeded with sugar crystals, facilitating crystal formation and drying.[89] Molasses is a by-product of the process and the fiber from the stems, known as bagasse,[89] is burned to provide energy for the sugar extraction process. The crystals of raw sugar have a sticky brown coating and either can be used as they are, can be bleached by sulfur dioxide, or can be treated in a carbonatation process to produce a whiter product.[89] About 2,500 litres (660 US gal) of irrigation water is needed for every one kilogram (2.2 pounds) of sugar produced.[90]

    Sugar beet

    [edit]

    Sugar beet production – 2022
    CountryMillions of tonnes
     Russia48.9
     France31.5
     United States29.6
     Germany28.2
    World260
    Source: FAO[86]

    In 2022, global production of sugar beets was 260 million tonnes, led by Russia with 18.8% of the world total (table).

    Sugar beet became a major source of sugar in the 19th century when methods for extracting the sugar became available. It is a biennial plant,[91] a cultivated variety of Beta vulgaris in the family Amaranthaceae, the tuberous root of which contains a high proportion of sucrose. It is cultivated as a root crop in temperate regions with adequate rainfall and requires a fertile soil. The crop is harvested mechanically in the autumn and the crown of leaves and excess soil removed. The roots do not deteriorate rapidly and may be left in the field for some weeks before being transported to the processing plant where the crop is washed and sliced, and the sugar extracted by diffusion.[92] Milk of lime is added to the raw juice with calcium carbonate. After water is evaporated by boiling the syrup under a vacuum, the syrup is cooled and seeded with sugar crystals. The white sugar that crystallizes can be separated in a centrifuge and dried, requiring no further refining.[92]

    Refining

    [edit]

    See also: Sugar refineryNon-centrifugal cane sugar, and White sugar

    Refined sugar is made from raw sugar that has undergone a refining process to remove the molasses.[93][94] Raw sugar is sucrose which is extracted from sugarcane or sugar beet. While raw sugar can be consumed, the refining process removes unwanted tastes and results in refined sugar or white sugar.[95][96]

    The sugar may be transported in bulk to the country where it will be used and the refining process often takes place there. The first stage is known as affination and involves immersing the sugar crystals in a concentrated syrup that softens and removes the sticky brown coating without dissolving them. The crystals are then separated from the liquor and dissolved in water. The resulting syrup is treated either by a carbonatation or by a phosphatation process. Both involve the precipitation of a fine solid in the syrup and when this is filtered out, many of the impurities are removed at the same time. Removal of color is achieved by using either a granular activated carbon or an ion-exchange resin. The sugar syrup is concentrated by boiling and then cooled and seeded with sugar crystals, causing the sugar to crystallize out. The liquor is spun off in a centrifuge and the white crystals are dried in hot air and ready to be packaged or used. The surplus liquor is made into refiners’ molasses.[97]

    The International Commission for Uniform Methods of Sugar Analysis sets standards for the measurement of the purity of refined sugar, known as ICUMSA numbers; lower numbers indicate a higher level of purity in the refined sugar.[98]

    Refined sugar is widely used for industrial needs for higher quality. Refined sugar is purer (ICUMSA below 300) than raw sugar (ICUMSA over 1,500).[99] The level of purity associated with the colors of sugar, expressed by standard number ICUMSA, the smaller ICUMSA numbers indicate the higher purity of sugar.[99]

    Forms and uses

    [edit]

    Crystal size

    [edit]

    See also: Rock candySucrose, and Powdered sugar

    Misri crystals

    Rock candy coloured with green dye

    • Coarse-grain sugar, also known as sanding sugar, composed of reflective crystals with grain size of about 1 to 3 mm, similar to kitchen salt. Used atop baked products and candies, it will not dissolve when subjected to heat and moisture.[100]
    • Granulated sugar (about 0.6 mm crystals), also known as table sugar or regular sugar, is used at the table, to sprinkle on foods and to sweeten hot drinks (coffee and tea), and in home baking to add sweetness and texture to baked products (cookies and cakes) and desserts (pudding and ice cream). It is also used as a preservative to prevent micro-organisms from growing and perishable food from spoiling, as in candied fruits, jams, and marmalades.[101]
    • Milled sugars such as powdered sugar (icing sugar) are ground to a fine powder. They are used for dusting foods and in baking and confectionery.[102][100]
    • Screened sugars such as caster sugar are crystalline products separated according to the size of the grains. They are used for decorative table sugars, for blending in dry mixes and in baking and confectionery.[102]

    Shapes

    [edit]

    “Lump sugar” redirects here. For the South Korean film, see Lump Sugar.

    Sugar cubes
    • Cube sugar (sometimes called sugar lumps) are white or brown granulated sugars lightly steamed and pressed together in block shape. They are used to sweeten drinks.[102]
    • Sugarloaf was the usual cone-form in which refined sugar was produced and sold until the late 19th century.[103]

    Brown sugars

    [edit]

    Main article: Brown sugar

    Brown sugar examples: Muscovado (top), dark brown (left), light brown (right)

    Brown sugars are granulated sugars, either containing residual molasses, or with the grains deliberately coated with molasses to produce a light- or dark-colored sugar such as muscovado and turbinado. They are used in baked goods, confectionery, and toffees.[102] Their darkness is due to the amount of molasses they contain. They may be classified based on their darkness or country of origin.[100]

    Liquid sugars

    [edit]

    A jar of honey with a dipper and a biscuit
    • Syrups are thick, viscous liquids consisting primarily of a solution of sugar in water. They are used in the food processing of a wide range of products including beverages, hard candyice cream, and jams.[102]
      • Inverted sugar syrup, commonly known as invert syrup or invert sugar, is a mixture of two simple sugars—glucose and fructose—that is made by heating granulated sugar in water. It is used in breads, cakes, and beverages for adjusting sweetness, aiding moisture retention and avoiding crystallization of sugars.[102]
    • Molasses and treacle are obtained by removing sugar from sugarcane or sugar beet juice, as a byproduct of sugar production. They may be blended with the above-mentioned syrups to enhance sweetness and used in a range of baked goods and confectionery including toffees and licorice.[102]
    • In winemakingfruit sugars are converted into alcohol by a fermentation process. If the must formed by pressing the fruit has a low sugar content, additional sugar may be added to raise the alcohol content of the wine in a process called chaptalization. In the production of sweet wines, fermentation may be halted before it has run its full course, leaving behind some residual sugar that gives the wine its sweet taste.[104]

    Other sweeteners

    [edit]

    See also: Saccharin

    • Low-calorie sweeteners are often made of maltodextrin with added sweeteners. Maltodextrin is an easily digestible synthetic polysaccharide consisting of short chains of three or more glucose molecules and is made by the partial hydrolysis of starch.[105] Strictly, maltodextrin is not classified as sugar as it contains more than two glucose molecules, although its structure is similar to maltose, a molecule composed of two joined glucose molecules.
    • Polyols are sugar alcohols and are used in chewing gums where a sweet flavor is required that lasts for a prolonged time in the mouth.[106]

    Consumption

    [edit]

    Worldwide sugar provides 10% of the daily calories (based on a 2000 kcal diet).[107] In 1750, the average Briton got 72 calories a day from sugar. In 1913, this had risen to 395. In 2015, sugar still provided around 14% of the calories in British diets.[108] According to one source, per capita consumption of sugar in 2016 was highest in the United States, followed by Germany and the Netherlands.[109]

    Nutrition and flavor

    [edit]

    Nutritional value per 100 g (3.5 oz)
    Energy1,576 kJ (377 kcal)
    Carbohydrates97.33 g
    Sugars96.21 g
    Dietary fiber0 g
    Fat0 g
    Protein0 g
    showVitamins and minerals
    Other constituentsQuantity
    Water1.77 g
    Full link to USDA database entry
    Percentages estimated using US recommendations for adults,[110] except for potassium, which is estimated based on expert recommendation from the National Academies.[111]
    Nutritional value per 100 g (3.5 oz)
    Energy1,619 kJ (387 kcal)
    Carbohydrates99.98 g
    Sugars99.91 g
    Dietary fiber0 g
    Fat0 g
    Protein0 g
    showVitamins and minerals
    Other constituentsQuantity
    Water0.03 g
    Full link to USDA database entry
    Percentages estimated using US recommendations for adults,[110] except for potassium, which is estimated based on expert recommendation from the National Academies.[111]

    Brown and white granulated sugar are 97% to nearly 100% carbohydrates, respectively, with less than 2% water, and no dietary fiber, protein or fat (table). Brown sugar contains a moderate amount of iron (15% of the Reference Daily Intake in a 100 gram amount, see table), but a typical serving of 4 grams (one teaspoon), would provide 15 calories and a negligible amount of iron or any other nutrient.[112] Because brown sugar contains 5–10% molasses reintroduced during processing, its value to some consumers is a richer flavor than white sugar.[113]

    Health effects

    [edit]

    General

    [edit]

    High sugar consumption damages human health more than it provides nutritional benefit, and in particular is associated with a risk of cardiometabolic health detriments.[3]

    Sugar industry funding and health information

    [edit]

    Main article: Sugar marketing § Influence on health information and guidelines

    Sugar refiners and manufacturers of sugary foods and drinks have sought to influence medical research and public health recommendations,[114][115] with substantial and largely clandestine spending documented from the 1960s to 2016.[116][117][118][119] The results of research on the health effects of sugary food and drink differ significantly, depending on whether the researcher has financial ties to the food and drink industry.[120][121][122] A 2013 medical review concluded that “unhealthy commodity industries should have no role in the formation of national or international NCD [non-communicable disease] policy”.[123] Similar efforts to steer coverage of sugar-related health information have been made in popular media, including news media and social media.[124][125][126]

    Obesity and metabolic syndrome

    [edit]

    Main article: Diet and obesity § Sugar consumption

    A 2003 technical report by the World Health Organization (WHO) provides evidence that high intake of sugary drinks (including fruit juice) increases the risk of obesity by adding to overall energy intake.[127] By itself, sugar is doubtfully a factor causing obesity and metabolic syndrome.[128] Meta-analysis showed that excessive consumption of sugar-sweetened beverages increased the risk of developing type 2 diabetes and metabolic syndrome – including weight gain[129] and obesity – in adults and children.[130][131]

    Cancer

    [edit]

    Sugar consumption does not directly cause cancer.[132][133][134] Cancer Council Australia have stated that “there is no evidence that consuming sugar makes cancer cells grow faster or cause cancer”.[132] There is an indirect relationship between sugar consumption and obesity-related cancers through increased risk of excess body weight.[134][132][135]

    The American Institute for Cancer Research and World Cancer Research Fund recommend that people limit sugar consumption.[136][137]

    There is a popular misconception that cancer can be treated by reducing sugar and carbohydrate intake to supposedly “starve” tumours. In reality, the health of people with cancer is best served by maintaining a healthy diet.[138]

    Cognition

    [edit]

    Despite some studies suggesting that sugar consumption causes hyperactivity, the quality of evidence is low[139] and it is generally accepted within the scientific community that the notion of children’s ‘sugar rush’ is a myth.[140][141] A 2019 meta-analysis found that sugar consumption does not improve mood, but can lower alertness and increase fatigue within an hour of consumption.[142] One review of low-quality studies of children consuming high amounts of energy drinks showed association with higher rates of unhealthy behaviors, including smoking and excessive alcohol use, and with hyperactivity and insomnia, although such effects could not be specifically attributed to sugar over other components of those drinks such as caffeine.[143]

    Tooth decay

    [edit]

    The WHO, Action on Sugar and the Scientific Advisory Committee on Nutrition (SACN) consider free sugars an essential dietary factor in the development of dental caries.[144][145][146] WHO have stated that “dental caries can be prevented by avoiding dietary free sugars”.[144]

    A review of human studies showed that the incidence of caries is lower when sugar intake is less than 10% of total energy consumed.[147] Sugar-sweetened beverage consumption is associated with an increased risk of tooth decay.[148]

    Nutritional displacement

    [edit]

    The “empty calories” argument states that a diet high in added (or ‘free’) sugars will reduce consumption of foods that contain essential nutrients.[149] This nutrient displacement occurs if sugar makes up more than 25% of daily energy intake,[150] a proportion associated with poor diet quality and risk of obesity.[151] Displacement may occur at lower levels of consumption.[150]

    [edit]

    The WHO recommends that both adults and children reduce the intake of free sugars to less than 10% of total energy intake, and suggests a reduction to below 5%. “Free sugars” include monosaccharides and disaccharides added to foods, and sugars found in fruit juice and concentrates, as well as in honey and syrups. According to the WHO, “[t]hese recommendations were based on the totality of available evidence reviewed regarding the relationship between free sugars intake and body weight (low and moderate quality evidence) and dental caries (very low and moderate quality evidence).”[2]

    On 20 May 2016, the U.S. Food and Drug Administration announced changes to the Nutrition Facts panel displayed on all foods, to be effective by July 2018. New to the panel is a requirement to list “added sugars” by weight and as a percent of Daily Value (DV). For vitamins and minerals, the intent of DVs is to indicate how much should be consumed. For added sugars, the guidance is that 100% DV should not be exceeded. 100% DV is defined as 50 grams. For a person consuming 2000 calories a day, 50 grams is equal to 200 calories and thus 10% of total calories—the same guidance as the WHO.[152] To put this in context, most 12-US-fluid-ounce (355 ml) cans of soda contain 39 grams of sugar. In the United States, a government survey on food consumption in 2013–2014 reported that, for men and women aged 20 and older, the average total sugar intakes—naturally occurring in foods and added—were, respectively, 125 and 99 g/day.[153]

    Measurements

    [edit]

    Various culinary sugars have different densities due to differences in particle size and inclusion of moisture. The “Engineering Resources – Bulk Density Chart” published in Powder and Bulk gives values for bulk densities:[154]

    • Beet sugar 0.80 g/mL
    • Dextrose sugar 0.62 g/mL ( = 620 kg/m^3)
    • Granulated sugar 0.70 g/mL
    • Powdered sugar 0.56 g/mL

    Society and culture

    [edit]

    Manufacturers of sugary products, such as soft drinks and candy, and the Sugar Research Foundation have been accused of trying to influence consumers and medical associations in the 1960s and 1970s by creating doubt about the potential health hazards of sucrose overconsumption, while promoting saturated fat as the main dietary risk factor in cardiovascular diseases.[116] In 2016, the criticism led to recommendations that diet policymakers emphasize the need for high-quality research that accounts for multiple biomarkers on development of cardiovascular diseases.[116]

    Originally, no sugar was white; anthropologist Sidney Mintz writes that white likely became understood as the ideal after groups who associated the color white with purity transferred their value to sugar.[155] In India, sugar frequently appears in religious observances. For ritual purity, such sugar cannot be white.[155]

    [edit]

    • Brown sugar crystals
    • Whole date sugar
    • Whole cane sugar (grey), vacuum-dried
    • Whole cane sugar (brown), vacuum-dried
    • Raw crystals of unrefined, unbleached sugar
  • Sugarcane (Perennial Grass)

    Sugarcane or sugar cane is a species of tall, perennial grass (in the genus Saccharum, tribe Andropogoneae) that is used for sugar production. The plants are 2–6 m (6–20 ft) tall with stout, jointed, fibrous stalks that are rich in sucrose,[1] which accumulates in the stalk internodes. Sugarcanes belong to the grass family, Poaceae, an economically important flowering plant family that includes maize, wheat, rice, and sorghum, and many forage crops. It is native to New Guinea.[2]

    Sugarcane was an ancient crop of the Austronesian and Papuan people. The best evidence available today points to the New Guinea area as the site of the original domestication of Saccharum officinarum.[3] It was introduced to PolynesiaIsland Melanesia, and Madagascar in prehistoric times via Austronesian sailors. It was also introduced by Austronesian sailors to India and then to Southern China by 500 BC, via trade. The Persians and Greeks encountered the famous “reeds that produce honey without bees” in India between the sixth and fourth centuries BC. They adopted and then spread sugarcane agriculture.[4] By the eighth century, sugar was considered a luxurious and expensive spice from India, and merchant trading spread its use across the Mediterranean and North Africa. In the 18th century, sugarcane plantations began in the Caribbean, South American, Indian Ocean, and Pacific island nations. The need for sugar crop laborers became a major driver of large migrations, some people voluntarily accepting indentured servitude[5] and others forcibly imported as slaves.[6]

    Grown in tropical and subtropical regions, sugarcane is the world’s largest crop by production quantity, totalling 1.9 billion tonnes in 2020, with Brazil accounting for 40% of the world total. Sugarcane accounts for 79% of sugar produced globally (most of the rest is made from sugar beets). About 70% of the sugar produced comes from Saccharum officinarum and its hybrids.[7] All sugarcane species can interbreed, and the major commercial cultivars are complex hybrids.[8]

    White sugar is produced from sugarcane in specialized mill factories. Sugarcane reeds are used to make pens, mats, screens, and thatch. The young, unexpanded flower head of Saccharum edule (duruka) is eaten raw, steamed, or toasted, and prepared in various ways in Southeast Asia, such as certain island communities of Indonesia as well as in Oceanic countries like Fiji.[9] The direct use of sugar cane to produce ethanol for biofuel is projected to potentially surpass the production of white sugar as an end product.

    Etymology

    [edit]

    The term sugarcane is a combination of two words: “sugar” and “cane”. The former ultimately derives from Sanskrit शर्करा (śárkarā) as the crop originated in Southeast Asia. As sugar was traded and spread West, this became سُكَّر (sukkar) in Arabicsaccharum or succarum in Latinzúcchero in Italian, and eventually sucre in both Middle French and Middle English. The second term “cane” began to be used alongside it as the crop was grown on plantations in the CaribbeanGanna is the Hindi word for sugarcane.[10]

    Characteristics

    [edit]

    Sugarcane is the most widely produced primary crop in the world

    Sugarcane, a perennial tropical grass, exhibits a unique growth pattern characterized by lateral shoots emerging at its base, leading to the development of multiple stems. These stems typically attain a height of 3 to 4 meters (approximately 10 to 13 feet) and possess a diameter of about 5 centimeters (approximately 2 inches). As these stems mature, they evolve into cane stalks, constituting a substantial portion of the entire plant, accounting for roughly 75% of its composition.[citation needed]

    A fully mature cane stalk generally comprises a composition of around 11–16% fiber, 12–16% soluble sugars, 2–3% non-sugar carbohydrates, and 63–73% water content. The successful cultivation of sugarcane hinges on a delicate interplay of several factors, including climatic conditions, soil properties, irrigation methods, fertilization practices, pest and disease management, the selection of specific varieties, and the timing of the harvest.[citation needed]

    In terms of yield, the average production of cane stalk stands at 60–70 tonnes per hectare (equivalent to 24–28 long tons per acre or 27–31 short tons per acre) annually. However, this yield figure is not fixed and can vary significantly, ranging from 30 to 180 tonnes per hectare. This variance is contingent upon the level of knowledge applied and the approach to crop management embraced in the cultivation of sugarcane. Ultimately, the successful cultivation of this valuable crop demands a thoughtful integration of various factors to optimize its growth and productivity.[citation needed]

    Sugarcane is a cash crop, but it is also used as livestock fodder.[11] Sugarcane genome is one of the most complex plant genomes known, mostly due to interspecific hybridization and polyploidization.[12][13]

    • Cut sugarcane
    • Sugarcane canopy

    History

    [edit]

    See also: Domesticated plants and animals of Austronesia and History of sugar

    The two centers of domestication for sugarcane are one for Saccharum officinarum by Papuans in New Guinea and another for Saccharum sinense by Austronesians in Taiwan and southern China. Papuans and Austronesians originally primarily used sugarcane as food for domesticated pigs. The spread of both S. officinarum and S. sinense is closely linked to the migrations of the Austronesian peoplesSaccharum barberi was only cultivated in India after the introduction of S. officinarum.[14][15]

    Map showing centers of origin of Saccharum officinarum in New Guinea, S. sinensis in southern China and Taiwan, and S. barberi in India; dotted arrows represent Austronesian introductions[16]

    S. officinarum was first domesticated in New Guinea and the islands east of the Wallace Line by Papuans, where it is the modern center of diversity. Beginning around 6,000 BP, several strains were selectively bred from the native Saccharum robustum. From New Guinea, it spread westwards to Maritime Southeast Asia after contact with Austronesians, where it hybridized with Saccharum spontaneum.[15]

    The second domestication center is southern China and Taiwan, where S. sinense was a primary cultigen of the Austronesian peoples. Words for sugarcane are reconstructed as *təbuS or *CebuS in Proto-Austronesian, which became *tebuh in Proto-Malayo-Polynesian. It was one of the original major crops of the Austronesian peoples from at least 5,500 BP. Introduction of the sweeter S. officinarum may have gradually replaced it throughout its cultivated range in maritime Southeast Asia.[17][18][16][19][20]

    Map showing sugar cane India as the origin of the westward spread, followed by small areas in Africa, and then smaller areas on Atlantic Islands west of Africa
    The westward diffusion of sugarcane in pre-Islamic times (shown in red), in the medieval Muslim world (green), and in the 15th century by the Portuguese on the Madeira archipelago, and by the Spanish on the Canary Islands archipelago (islands west of Africa, circled by violet lines)[21]

    From Insular Southeast Asia, S. officinarum was spread eastward into Polynesia and Micronesia by Austronesian voyagers as a canoe plant by around 3,500 BP. It was also spread westward and northward by around 3,000 BP to China and India by Austronesian traders, where it further hybridized with S. sinense and S. barberi. From there, it spread further into western Eurasia and the Mediterranean.[15][16]

    The earliest known production of crystalline sugar began in northern India. The earliest evidence of sugar production comes from ancient Sanskrit and Pali texts.[22][23][24][25] Around the eighth century, Muslim and Arab traders introduced sugar from medieval India to the other parts of the Abbasid Caliphate in the Mediterranean, MesopotamiaEgypt, North Africa, and Andalusia. By the 10th century, sources state that every village in Mesopotamia grew sugarcane.[21] It was among the early crops brought to the Americas by the Spanish, mainly Andalusians, from their fields in the Canary Islands, and the Portuguese from their fields in the Madeira Islands. An article on sugarcane cultivation in Spain is included in Ibn al-‘Awwam‘s 12th-century Book on Agriculture.[26]

    The first chemically refined sugar appeared on the scene in India about 2,500 years ago. From there, the technique spread east towards China, and west towards Persia and the early Islamic worlds, eventually reaching the Mediterranean in the 13th century. Cyprus and Sicily became important centers for sugar production.

    In colonial times, sugar formed one side of the triangle trade of New World raw materials, along with European manufactured goods, and African slavesChristopher Columbus first brought sugarcane to the Caribbean (and the New World) during his second voyage to the Americas, initially to the island of Hispaniola (modern day Haiti and the Dominican Republic). The first sugar harvest happened in Hispaniola in 1501; many sugar mills were constructed in Cuba and Jamaica by the 1520s.[27] The Portuguese introduced sugarcane to Brazil. By 1540, there were 800 cane sugar mills in Santa Catarina Island and another 2,000 on the north coast of Brazil, Demarara, and Suriname.[citation needed]

    Sugar, often in the form of molasses, was shipped from the Caribbean to Europe or New England, where it was used to make rum. The profits from the sale of sugar were then used to purchase manufactured goods, which were then shipped to West Africa, where they were bartered for slaves. The slaves were then brought back to the Caribbean to be sold to sugar planters. The profits from the sale of the slaves were then used to buy more sugar, which was shipped to Europe. Toil in the sugar plantations became a main basis for a vast network of forced population movement, supplying people to work under brutal coercion.[citation needed]

    Lithograph of sugarcane being ground using a windmill on a sugar plantation in the British colony of Antigua, 1823
    Black-and-white photograph of sugarcane standing in field
    A sugar plantation on the island of Jamaica in the late 19th century

    The passage of the 1833 Slavery Abolition Act led to the abolition of slavery through most of the British Empire, and many of the emancipated slaves no longer worked on sugarcane plantations when they had a choice. West Indian planters, therefore, needed new workers, and they found cheap labour in China and India.[28][29] The people were subject to indenture, a long-established form of contract, which bound them to unfree labour for a fixed term. The conditions where the indentured servants worked were frequently abysmal, owing to a lack of care among the planters.[30] The first ships carrying indentured labourers from India left in 1836.[31] The migrations to serve sugarcane plantations led to a significant number of ethnic Indians, Southeast Asians, and Chinese people settling in various parts of the world.[32] In some islands and countries, the South Asian migrants now constitute between 10 and 50% of the population. Sugarcane plantations and Asian ethnic groups continue to thrive in countries such as FijiSouth AfricaMyanmarSri LankaMalaysiaIndonesia, the PhilippinesGuyana, Jamaica, Trinidad, Martinique, French Guiana, Guadeloupe, GrenadaSt. LuciaSt. VincentSt. KittsSt. Croix, Suriname, Nevis, and Mauritius.[31][33]

    Indian sugarcane press, circa 1905

    Between 1863 and 1900, merchants and plantation owners in Queensland and New South Wales (now part of the Commonwealth of Australia) brought between 55,000 and 62,500 people from the South Pacific islands to work on sugarcane plantations. An estimated one-third of these workers were coerced or kidnapped into slavery (known as blackbirding); many others were paid very low wages. Between 1904 and 1908, most of the 10,000 remaining workers were deported in an effort to keep Australia racially homogeneous and protect white workers from cheap foreign labour.[34]

    Cuban sugar derived from sugarcane was exported to the USSR, where it received price supports and was ensured a guaranteed market. The 1991 dissolution of the Soviet state forced the closure of most of Cuba’s sugar industry.

    Sugarcane remains an important part of the economy of Cuba, Guyana, BelizeBarbados, and Haiti, along with the Dominican Republic, Guadeloupe, Jamaica, and other islands.

    About 70% of the sugar produced globally comes from S. officinarum and hybrids using this species.[7]

    Sugar[clarification needed] occupies 26,942,686 hectares of land across the globe and is the third most valuable crop.

    A 19th-century lithograph by Theodore Bray showing a sugarcane plantation: On the right is the “white officer”, the European overseer. Slave workers toil during the harvest. To the left is a flat-bottomed vessel for cane transportation.

    Cultivation

    [edit]

    Sugarcane plantation, Mauritius
    Sugarcane plantation in Bangladesh
    Planting sugarcane in Puerto Rico
    Sugarcane fields

    Sugarcane cultivation requires a tropical or subtropical climate, with a minimum of 60 cm (24 in) of annual moisture. It is one of the most efficient photosynthesizers in the plant kingdom. It is a C4 plant, able to convert up to 1% of incident solar energy into biomass.[35] In primary growing regions across the tropics and subtropics, sugarcane crops can produce over 15 kg/m2 of cane.[citation needed]

    Sugar cane accounted for around 21% of the global crop production over the 2000–2021 period. The Americas was the leading region in the production of sugar cane (52% of the world total).[36]

    Once a major crop of the southeastern region of the United States, sugarcane cultivation declined there during the late 20th century, and is primarily confined to small plantations in FloridaLouisiana, and southeast Texas in the 21st century. Sugarcane cultivation ceased in Hawaii when the last operating sugar plantation in the state shut down in 2016.[37]


    Sugarcane is cultivated in the tropics and subtropics in areas with a plentiful supply of water for a continuous period of more than 6–7 months each year, either from natural rainfall or through irrigation. The crop does not tolerate severe frosts. Therefore, most of the world’s sugarcane is grown between 22°N and 22°S, and some up to 33°N and 33°S.[38] When sugarcane crops are found outside this range, such as the Natal region of South Africa, it is normally due to anomalous climatic conditions in the region, such as warm ocean currents that sweep down the coast. In terms of altitude, sugarcane crops are found up to 1,600 m or 5,200 ft close to the equator in countries such as ColombiaEcuador, and Peru.[39]

    Sugarcane can be grown on many soils ranging from highly fertile, well-drained mollisols, through heavy cracking vertisols, infertile acid oxisols and ultisols, peaty histosols, to rocky andisols. Both plentiful sunshine and water supplies increase cane production. This has made desert countries with good irrigation facilities such as Egypt some of the highest-yielding sugarcane-cultivating regions. Sugarcane consumes 9% of the world’s potash fertilizer production.[40]

    Although some sugarcanes produce seeds, modern stem cutting has become the most common reproduction method.[41] Each cutting must contain at least one bud, and the cuttings are sometimes hand-planted. In more technologically advanced countries, such as the United States and Australia, billet planting is common. Billets (stalks or stalk sections) harvested by a mechanical harvester are planted by a machine that opens and recloses the ground. Once planted, a stand can be harvested several times; after each harvest, the cane sends up new stalks, called ratoons.[42] Successive harvests give decreasing yields, eventually justifying replanting. Two to 10 harvests are usually made depending on the type of culture. In a country with a mechanical agriculture looking for a high production of large fields, as in North America, sugarcanes are replanted after two or three harvests to avoid a lowering yields. In countries with a more traditional type of agriculture with smaller fields and hand harvesting, as in the French island of Réunion, sugarcane is often harvested up to 10 years before replanting.[citation needed]

    Sugarcane is harvested by hand and mechanically. Hand harvesting accounts for more than half of production, and is dominant in the developing world. In hand harvesting, the field is first set on fire. The fire burns up dry leaves, and chases away or kills venomous snakes, without harming the stalks and roots. Harvesters then cut the cane just above ground-level using cane knives or machetes. A skilled harvester can cut 500 kg (1,100 lb) of sugarcane per hour.[failed verification][43]

    Mechanical harvesting uses a combine, or sugarcane harvester.[44] The Austoft 7000 series, the original modern harvester design, has now been copied by other companies, including Cameco / John Deere.[citation needed] The machine cuts the cane at the base of the stalk, strips the leaves, chops the cane into consistent lengths and deposits it into a transporter following alongside. The harvester then blows the trash back onto the field. Such machines can harvest 100 long tons (100 t) each hour, but harvested cane must be rapidly processed. Once cut, sugarcane begins to lose its sugar content, and damage to the cane during mechanical harvesting accelerates this decline. This decline is offset because a modern chopper harvester can complete the harvest faster and more efficiently than hand cutting and loading. Austoft also developed a series of hydraulic high-lift infield transporters to work alongside its harvesters to allow even more rapid transfer of cane to, for example, the nearest railway siding. This mechanical harvesting does not require the field to be set on fire; the residue left in the field by the machine consists of cane tops and dead leaves, which serve as mulch for the next planting.

    Plantations in Brazil, the largest producer in the world

    Pests

    [edit]

    The cane beetle (also known as cane grub) can substantially reduce crop yield by eating roots; it can be controlled with imidacloprid (Confidor) or chlorpyrifos (Lorsban). Other important pests are the larvae of some butterfly/moth species, including the turnip moth, the sugarcane borer (Diatraea saccharalis), the African sugarcane borer (Eldana saccharina), the Mexican rice borer (Eoreuma loftini), the African armyworm (Spodoptera exempta), leafcutter antstermitesspittlebugs (especially Mahanarva fimbriolata and Deois flavopicta), and Migdolus fryanus (a beetle). The planthopper insect Eumetopina flavipes acts as a virus vector, which causes the sugarcane disease ramu stunt.[45][46] Sesamia grisescens is a major pest in Papua New Guinea and so is a serious concern for the Australian industry were it to cross over.[47] To head off such a problem, the Federal Government has pre-announced that they would cover 80% of response costs if it were necessary.[47]

    Pathogens

    [edit]

    Main article: List of sugarcane diseases

    Numerous pathogens infect sugarcane, such as sugarcane grassy shoot disease caused by Candidatus Phytoplasma sacchari,[48] whiptail disease or sugarcane smutpokkah boeng caused by Fusarium moniliformeXanthomonas axonopodis bacteria causes Gumming Disease, and red rot disease caused by Colletotrichum falcatumViral diseases affecting sugarcane include sugarcane mosaic virusmaize streak virus, and sugarcane yellow leaf virus.[49]

    Yang et al., 2017 provides a genetic map developed for USDA ARS-run breeding programs for brown rust of sugarcane.[50]

    Nitrogen fixation

    [edit]

    Some sugarcane varieties are capable of fixing atmospheric nitrogen in association with the bacterium Gluconacetobacter diazotrophicus.[51] Unlike legumes and other nitrogen-fixing plants that form root nodules in the soil in association with bacteria, G. diazotrophicus lives within the intercellular spaces of the sugarcane’s stem.[52][53] Coating seeds with the bacteria was assayed in 2006 with the intention of enabling crop species to fix nitrogen for its own use.[54]

    Conditions for sugarcane workers

    [edit]

    At least 20,000 people are estimated to have died of chronic kidney disease in Central America in the past two decades, most of them sugarcane workers along the Pacific coast. This may be due to working long hours in the heat without adequate fluid intake.[55] Additionally, some of the workers are being exposed to hazards such as: high temperatures, harmful pesticides, and poisonous or venomous animals. This occurs during the process of cutting the sugarcane manually, causing physical ailments due to constant repetitive movements for hours every work day.[56]

    Processing

    [edit]Duration: 1 minute and 59 seconds.1:59Non-centrifugal cane sugar (jaggery) production near Inle Lake (Myanmar), crushing and boiling stage

    Traditionally, sugarcane processing requires two stages. Mills extract raw sugar from freshly harvested cane and “mill-white” sugar is sometimes produced immediately after the first stage at sugar-extraction mills, intended for local consumption. Sugar crystals appear naturally white in color during the crystallization process. Sulfur dioxide is added to inhibit the formation of color-inducing molecules and to stabilize the sugar juices during evaporation.[57][58] Refineries, often located nearer to consumers in North America, Europe, and Japan, then produce refined white sugar, which is 99% sucrose. These two stages are slowly merging. Increasing affluence in the sugarcane-producing tropics increases demand for refined sugar products, driving a trend toward combined milling and refining.[59]

    Milling

    [edit]

    Main article: Sugar cane mill

    Photo of man holding bar that penetrates large tank
    Manually extracting juice from sugarcane
    Photo of truck hauling trailer
    A truck hauls cane to a sugar mill in Florida.

    Sugarcane processing produces cane sugar (sucrose) from sugarcane. Other products of the processing include bagasse, molasses, and filter cake.

    Bagasse, the residual dry fiber of the cane after cane juice has been extracted, is used for several purposes:[60]

    • fuel for the boilers and kilns
    • production of paper, paperboard products, and reconstituted panelboard
    • agricultural mulch
    • as a raw material for production of chemicals
    Photo of shorter building with smoke coming out of smokestack next to five-story office building
    Santa Elisa sugarcane processing plant in Sertãozinho, one of the largest and oldest in Brazil

    The primary use of bagasse and bagasse residue is as a fuel source for the boilers in the generation of process steam in sugar plants. Dried filter cake is used as an animal feed supplement, fertilizer, and source of sugarcane wax.[citation needed]

    Molasses is produced in two forms: blackstrap, which has a characteristic strong flavor, and a purer molasses syrup. Blackstrap molasses is sold as a food and dietary supplement. It is also a common ingredient in animal feed, and is used to produce ethanol, rum, and citric acid. Purer molasses syrups are sold as molasses, and may also be blended with maple syrup, invert sugars, or corn syrup. Both forms of molasses are used in baking.[citation needed]

    Refining

    [edit]

    Brown and white sugar crystals

    Sugar refining further purifies the raw sugar. It is first mixed with heavy syrup and then centrifuged in a process called “affination”. Its purpose is to wash away the sugar crystals’ outer coating, which is less pure than the crystal interior. The remaining sugar is then dissolved to make a syrup, about 60% solids by weight.[61]

    The sugar solution is clarified by the addition of phosphoric acid and calcium hydroxide, which combine to precipitate calcium phosphate. The calcium phosphate particles entrap some impurities and absorb others, and then float to the top of the tank, where they can be skimmed off. An alternative to this “phosphatation” technique is “carbonatation“, which is similar, but uses carbon dioxide and calcium hydroxide to produce a calcium carbonate precipitate.

    After filtering any remaining solids, the clarified syrup is decolorized by filtration through activated carbonBone char or coal-based activated carbon is traditionally used in this role.[62] Some remaining color-forming impurities are adsorbed by the carbon. The purified syrup is then concentrated to supersaturation and repeatedly crystallized in a vacuum, to produce white refined sugar. As in a sugar mill, the sugar crystals are separated from the molasses by centrifuging. Additional sugar is recovered by blending the remaining syrup with the washings from affination and again crystallizing to produce brown sugar. When no more sugar can be economically recovered, the final molasses still contains 30-35% sucrose and 10–25% glucose and fructose.[63]

    To produce granulated sugar, in which individual grains do not clump, sugar must be dried, first by heating in a rotary dryer, and then by blowing cool air through it for several days.

    Ribbon cane syrup

    [edit]

    Ribbon cane is a subtropical type that was once widely grown in the Southern United States, as far north as coastal North Carolina. The juice was extracted with horse- or mule-powered crushers; the juice was boiled, like maple syrup, in a flat pan, and then used in the syrup form as a food sweetener.[64] It is not currently a commercial crop, but a few growers find ready sales for their product.[citation needed]

    Production of sugarcane (2019)[65]

    Production

    [edit]

    Top sugarcane producers
    in 2022
    Numbers in million tonnes
    1.  Brazil724.4 (37.69%)
    2.  India439.4 (22.86%)
    3.  China103.4 (5.38%)
    4.  Thailand92.1 (4.79%)
    5.  Pakistan88 (4.58%)
    6.  Mexico55.3 (2.88%)
    7.  Colombia35 (1.82%)
    8.  Indonesia32.4 (1.69%)
    9.  United States31.5 (1.64%)
    10.  Australia28.7 (1.49%)
    World total1,922.1
    Source: FAOSTAT[66]

    In 2022, global production of sugarcane was 1.92 billion tonnes, with Brazil producing 38% of the world total, India with 23%, and China producing 5% (table).

    Worldwide, 26 million hectares were devoted to sugarcane cultivation in 2020.[66] The average worldwide yield of sugarcane crops in 2022 was 74 tonnes per hectare, led by Peru with 121 tonnes per hectare.[66] The theoretical possible yield for sugarcane is about 280 tonnes per hectare per year, and small experimental plots in Brazil have demonstrated yields of 236–280 tonnes of cane per hectare.[67][68]

    From 2008 to 2016, production of standards-compliant sugarcane experienced a compound annual growth rate of about 52%, while conventional sugarcane increased at less than 1%.[69]

    Environmental impacts

    [edit]

    Soil degradation and erosion

    [edit]

    The cultivation of sugarcane can lead to increased soil loss through the removal of soil at harvest, as well as improper irrigation practices, which can result in erosion.[70][71] Erosion is especially significant when the sugarcane is grown on slopes or hillsides, which increases the rate of water runoff.[70][71] Generally, it is recommended that sugarcane is not planted in areas with a slope greater than 8%.[70] However, in certain areas, such as parts of the Caribbean and South Africa, slopes greater than 20% have been planted.[70] Increased erosion can lead to the removal of organic and nutrient-rich material, which can decrease future crop yields. It can also result in sediments and other pollutants being washed into aquatic habitats, which can result in a wide range of environmental issues, including eutrophication and acidification.[70][71]

    Sugarcane cultivation can also result in soil compaction, which is caused by the use of heavy, infield machinery.[70] Along with impacting invertebrate and fauna within the upper layers of the soil, compaction can also lead to decreased porosity.[70][71] This in turn can increase surface runoff, resulting in greater leaching and erosion.[70]

    Habitat destruction

    [edit]

    Gases produced from sugarcane processing.

    Due to the large quantity of water required, sugarcane cultivation heavily relies on irrigation.[72] Additionally, since large amounts of soil are removed with the crop during harvest, significant washing occurs during the processing phase.[72] In many countries, such as India and Australia, this requirement has placed a strain on available resources, requiring the construction of barrages and other dams.[70][72] This has altered the amount of water reaching aquatic habitats, and has contributed to the degradation of ecosystems such as the Great Barrier Reef and Indus Delta.[70][72]

    Land cleared for sugarcane production.

    Sugarcane has also contributed to habitat destruction through the clearance of land.[70] Seven countries around the world devote more than 50% of their land to the cultivation of sugarcane.[70] Sugarcane fields have replaced tropical rain forests and wetlands.[70] While the majority of this clearance occurred in the past, expansions have occurred within the past couple decades, further contributing to habitat destruction.[71]

    Mitigation efforts

    [edit]

    A wide variety of mitigation efforts can be implemented to reduce the impacts of sugarcane cultivation.[70] Among these efforts is switching to alternative irrigation techniques, such as drip irrigation, which are more water efficient.[70] Water efficiency can also be improved by employing methods such as trash mulching, which has been shown to increase water intake and storage.[70][73] Along with reducing the overall water use, this method can also decrease soil runoff, and therefore prevent pollutants from entering the environment.[70] In areas with a slope greater than 11%, it is also recommended that zero tillage or cane strip planting are implemented to help prevent soil loss.[70]

    Sugarcane processing produces a wide variety of pollutants, including heavy metals and bagasse, which can be released into the environment through wastewater discharge.[70] To prevent this, alternative treatment methods such as high rate anaerobic digestions can be implemented to better treat this wastewater.[74] Stormwater drains can also be installed to prevent uncontrolled runoff from reaching aquatic ecosystems.[70]

    Ethanol

    [edit]

    Further information: Ethanol fuel

    See also: Biofuel

    A fuel pump in Brazil, offering cane ethanol (A) and gasoline (G)

    Ethanol is generally available as a byproduct of sugar production. It can be used as a biofuel alternative to gasoline, and is widely used in cars in Brazil. It is an alternative to gasoline, and may become the primary product of sugarcane processing, rather than sugar[citation needed]

    In Brazil, gasoline is required to contain at least 22% bioethanol.[75] This bioethanol is sourced from Brazil’s large sugarcane crop.

    The production of ethanol from sugarcane is more energy efficient than from corn or sugar beets or palm/vegetable oils, particularly if cane bagasse is used to produce heat and power for the process. Furthermore, if biofuels are used for crop production and transport, the fossil energy input needed for each ethanol energy unit can be very low. EIA estimates that with an integrated sugarcane to ethanol technology, the well-to-wheels CO2 emissions can be 90% lower than conventional gasoline.[75] A textbook on renewable energy[76] describes the energy transformation:

    Presently, 75 tons of raw sugarcane are produced annually per hectare in Brazil. The cane delivered to the processing plant is called burned and cropped (b&c), and represents 77% of the mass of the raw cane. The reason for this reduction is that the stalks are separated from the leaves (which are burned and whose ashes are left in the field as fertilizer), and from the roots that remain in the ground to sprout for the next crop. Average cane production is, therefore, 58 tons of b&c per hectare per year.

    Each ton of b&c yields 740 kg of juice (135 kg of sucrose and 605 kg of water) and 260 kg of moist bagasse (130 kg of dry bagasse). Since the lower heating value of sucrose is 16.5 MJ/kg, and that of the bagasse is 19.2 MJ/kg, the total heating value of a ton of b&c is 4.7 GJ of which 2.2 GJ come from the sucrose and 2.5 from the bagasse.

    Per hectare per year, the biomass produced corresponds to 0.27 TJ. This is equivalent to 0.86 W per square meter. Assuming an average insolation of 225 W per square meter, the photosynthetic efficiency of sugar cane is 0.38%.

    The 135 kg of sucrose found in 1 ton of b&c are transformed into 70 litres of ethanol with a combustion energy of 1.7 GJ. The practical sucrose-ethanol conversion efficiency is, therefore, 76% (compare with the theoretical 97%).

    One hectare of sugar cane yields 4,000 litres of ethanol per year (without any additional energy input, because the bagasse produced exceeds the amount needed to distill the final product). This, however, does not include the energy used in tilling, transportation, and so on. Thus, the solar energy-to-ethanol conversion efficiency is 0.13%.

    Bagasse applications

    [edit]

    Sugarcane bagasse

    Sugarcane is a major crop in many countries. It is one of the plants with the highest bioconversion efficiency. Sugarcane crop is able to efficiently fix solar energy, yielding some 55 tonnes of dry matter per hectare of land annually. After harvest, the crop produces sugar juice and bagasse, the fibrous dry matter. This dry matter is biomass with potential as fuel for energy production. Bagasse can also be used as an alternative source of pulp for paper production.[77]

    Sugarcane bagasse is a potentially abundant source of energy for large producers of sugarcane, such as Brazil, India, and China. According to one report, with use of latest technologies, bagasse produced annually in Brazil has the potential of meeting 20% of Brazil’s energy consumption by 2020.[78]

    Electricity production

    [edit]

    A number of countries, in particular those lacking fossil fuels, have implemented energy conservation and efficiency measures to minimize the energy used in cane processing, and export any excess electricity to the grid. Bagasse is usually burned to produce steam, which in turn creates electricity. Current technologies, such as those in use in Mauritius, produce over 100 kWh of electricity per tonne of bagasse. With a total world harvest of over one billion tonnes of sugarcane per year, the global energy potential from bagasse is over 100,000 GWh.[79] Using Mauritius as a reference, an annual potential of 10,000 GWh of additional electricity could be produced throughout Africa.[80] Electrical generation from bagasse could become quite important, particularly to the rural populations of sugarcane producing nations.

    Recent cogeneration technology plants are being designed to produce from 200 to over 300 kWh of electricity per tonne of bagasse.[81][82] As sugarcane is a seasonal crop, shortly after harvest the supply of bagasse would peak, requiring power generation plants to strategically manage the storage of bagasse.

    Biogas production

    [edit]

    A greener alternative to burning bagasse for the production of electricity is to convert bagasse into biogas. Technologies are being developed to use enzymes to transform bagasse into advanced biofuel and biogas.[78]

    Sugarcane as food

    [edit]

    Further information: Sugar

    Freshly squeezed sugarcane juice
    Nutritional value per 100 grams
    Energy242 kJ (58 kcal)
    Carbohydrates13.11 g
    Sugarsglucosefructose12.85 g2.27 g0.55 g
    Dietary fiber0.56 g
    Fat0.40
    Protein0.16 g
    showVitamins and minerals
    Nutrient Information from Indian Food Composition Database
    Percentages estimated using US recommendations for adults,[84] except for potassium, which is estimated based on expert recommendation from the National Academies.[85]

    In most countries where sugarcane is cultivated, several foods and popular dishes are derived directly from it, such as:

    • Raw sugarcane: chewed to extract the juice
    • Sayur nganten: an Indonesian soup made with the stem of trubuk (Saccharum edule), a type of sugarcane
    • Sugarcane juice: a combination of fresh juice, extracted by hand or small mills, with a touch of lemon and ice to make a popular drink, known variously as air tebuusacha rassguarabguarapa, guarapo, papelónaseer asabganna sharbatmostocaldo de cana, or nước mía
    • Syrup: a traditional sweetener in soft drinks worldwide but now largely supplanted in the US by high fructose corn syrup, which is less expensive because of corn subsidies and sugar tariffs[86]
    • Molasses: used as a sweetener and a syrup accompanying other foods, such as cheese or cookies
    • Jaggery: a solidified molasses, known as gurgud, or gul in modern Indo-Aryan, is traditionally produced by evaporating juice to make a thick sludge, and then cooling and molding it in buckets. Modern production partially freeze dries the juice to reduce caramelization and lighten its color. It is used as sweetener in cooking traditional entrees, sweets, and desserts.
    • Falernum: a sweet, and slightly alcoholic drink made from sugarcane juice
    • Cachaça: the most popular distilled alcoholic beverage in Brazil; it is a liquor made of the distillation of sugarcane juice.
    • Rum is a liquor made from sugarcane products, typically molasses, but sometimes also cane juice. It is most commonly produced in the Caribbean and environs.
    • Basi is a fermented alcoholic beverage made from sugarcane juice produced in the Philippines and Guyana.
    • Panela, solid pieces of sucrose and fructose obtained from the boiling and evaporation of sugarcane juice, is a food staple in Colombia and other countries in South and Central America.
    • Rapadura is a sweet flour that is one of the simplest refinings of sugarcane juice, common in Latin American countries such as Brazil, Argentina, and Venezuela (where it is known as papelón) and the Caribbean.
    • Rock candy: crystallized cane juice
    • Gâteau de Sirop
    • Viche, a homebrewed Colombian alcoholic beverage

    In the 21st century, it is estimated that sugar is potentially responsible for approximately 20% of the caloric content of modern diets.[87]

    Sugarcane as feed

    [edit]

    Many parts of the sugarcane are commonly used as animal feeds where the plants are cultivated. The leaves make a good forage for ruminants.[88]

    [edit]

    • Sugarcane flowering
    • Flowers of sugarcane
    • Evaporator with baffled pan and foam dipper for making ribbon cane syrup
    • A video of sugarcane juice extraction
    • Caipirinha, a cocktail made from sugarcane-derived cachaça