Names | |
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IUPAC name D-ribo-Hex-2-ulose | |
Systematic IUPAC name (3R,4R,5R)-1,3,4,5,6-Pentahydroxyhexan-2-one | |
Other names D-Allulose; D-Psicose; D-Ribo-2-hexulose; Pseudofructose | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.008.182 |
MeSH | psicose |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C6H12O6 | |
Molar mass | 180.156 g·mol−1 |
Melting point | 58 °C (136 °F; 331 K) [1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
D-Psicose (C6H12O6), also known as D-allulose or simply allulose, is an epimer of fructose that is used by some commercial food and beverage manufacturers as a low-calorie sweetener. [2] Allulose occurs naturally in small quantities in a variety of foods. It was first identified in the 1940s, although the enzymes needed to produce it on an industrial scale were not discovered until the 1990s.
The U.S. Food and Drug Administration (FDA) has accepted a petition for generally recognized as safe (GRAS) for allulose as a sugar substitute in various specified food categories. [3] [4] Because it is absorbed and metabolized differently from other sugars, the FDA has exempted allulose from the listing of total and added sugars on the Nutrition and Supplement Facts labels, but requires its weight listing as a carbohydrate, with 0.4 kcal/g (about 1/10 the calories of ordinary carbohydrates). [5]
Studies have shown the commercial product is not absorbed in the human body the way common sugars are and does not raise insulin levels, but more testing may be needed to evaluate any other potential side effects. [6] In 2020, the U.S. FDA accepted the conclusion by Samyang that the maximum tolerable consumption for a 60 kg adult was 33 to 36 grams per day. [7]
The sweetness of allulose is estimated to be 70% of the sweetness of sucrose. [8] [9] It has some cooling sensation and no bitterness. [2] Its taste is said to be sugar-like, in contrast to certain other sweeteners, like the high-intensity artificial sweeteners aspartame and saccharin. [2] The caloric value of allulose in humans is about 0.2 to 0.4 kcal/g, relative to about 4 kcal/g for typical carbohydrates. [9] [10] In rats, the relative energy value of allulose was found to be 0.007 kcal/g, or approximately 0.3% of that of sucrose. [11] Similar to the sugar alcohol erythritol, allulose is minimally metabolized and is excreted largely unchanged. [9] The glycemic index of allulose is very low or negligible. [2] [9]
Allulose is a weak inhibitor of the enzymes α-glucosidase, α-amylase, maltase, and sucrase. [2] Because of this, it can inhibit the metabolism of starch and disaccharides into monosaccharides in the gastrointestinal tract. [2] Additionally, allulose inhibits the absorption of glucose via transporters in the intestines. [2] For these reasons, allulose has potential antihyperglycemic effects, and has been found to reduce postprandial hyperglycemia in humans. [2] [10] Through modulation of lipogenic enzymes in the liver, allulose may also have antihyperlipidemic effects. [2] [10]
Due to its effect of causing incomplete absorption of carbohydrates from the gastrointestinal tract, and subsequent fermentation of these carbohydrates by intestinal bacteria, allulose can result in unpleasant symptoms such as flatulence, abdominal discomfort, and diarrhea. [2] The maximum non-effect dose of allulose in causing diarrhea in humans has been found to be 0.55 g/kg of body weight. [2] This is higher than that of most sugar alcohols (0.17–0.42 g/kg), but is less than that of erythritol (0.66–1.0+ g/kg). [12] [13] [14]
D-allulose was found to be more reactive than fructose and glucose in glycation reactions. [15]
A meta-analysis was conducted of the effect on postprandial glucose and insulin responses of adding a median of 5 grams of allulose (range, 2.5-10 g) to a fixed carbohydrate-containing drink or meal, versus the same meal alone. Overall, compared to the carbohydrate-containing meal alone, the same meal with a small dose of added allulose resulted in a 10% lower integrated area under the curve (iAUC) of postprandial glucose. [16] The quality of the evidence was rated as moderate. [16]
Allulose, also known by its systematic name D-ribo-2-hexulose as well as by the name D-psicose, is a monosaccharide and a ketohexose. [2] [11] It is a C3 epimer of fructose. [2] Fructose can be converted to allulose by the enzymes D-tagatose 3-epimerase (EC 5.1.3.31) and/or D-psicose 3-epimerase (EC 5.1.3.30), which has allowed for mass production of allulose. [2] The compound is found naturally in trace amounts in wheat, figs, raisins, maple syrup, and molasses. [2] [11] [17] Allulose has similar physical properties to those of regular sugar, such as bulk, mouthfeel, browning capability, and freeze point depression. [17] This makes it favorable for use as a sugar replacement in food products, including ice cream. [17]
In a paper produced for the European Food Safety Authority, the enzyme d-psicose 3-epimerase, manufactured by Matsutani Chemical Industry Co., Ltd, was investigated for safety and allergenicity. [18] No DNA of E. coli (used for production of the enzyme) was found in the enzyme preparation, and no match was found in the enzyme amino acid sequence with those of known allergens. [18]
Allulose was first discovered in the 1940s. [17] The first mass-production method for allulose was established when Ken Izumori at Kagawa University in Japan discovered the key enzyme, D-tagatose 3-epimerase, to convert fructose to allulose in 1994. [19] [20] This method of production has a high yield, but has a very high production cost.
In June 2012, the U.S. Food and Drug Administration (FDA) accepted the assertion of CJ CheilJedang, Inc. of South Korea that allulose is generally recognized as safe (GRAS) as a sugar substitute in various specified food categories. [3] In June 2014, a similar GRAS letter was issued to Matsutani Chemical Industry Company, Ltd. of Japan. [4] Non-GMO allulose manufactured by Samyang Corp. of South Korea was approved as GRAS in March 2020. [7]
In the European Union, although allulose is a naturally-occurring saccharide, under their regulations, monosaccharides and other saccharides are not considered food additives, and thus cannot be approved as such, but must be approved as ingredients. [21] CJ-Tereos Sweeteners of France filed for such an approval in April 2018. [21] The Allulose Novel Food Consortium (ANFC) was formed in 2021 by four Japanese, Korean, U.S. and European food ingredient companies to speed its approval as an ingredient in Europe, including exemption from sugar labelling. [22]
The U.S. FDA in October 2019 announced the exemption of allulose from total and added sugars on nutritional labels, but manufacturers must continue to include allulose in the total carbohydrates declaration, with a value of 0.4kcal/g, "0.4 calories per gram of allulose". [5]
Allulose is produced by an enzymatic reaction that converts fructose into allulose. [2] As of 2018, most commercially available allulose uses corn (maize) as the source of fructose. [23] Another source of fructose is from sugar beet. [24]
Commercial manufacturers and food laboratories are looking into properties of allulose that may differentiate it from sucrose and fructose sweeteners, including an ability to induce the high foaming property of egg white protein and the production of antioxidant substances produced through the Maillard reaction. [25]
Commercial uses of allulose include low-calorie sweeteners in beverages, yogurt, ice cream, baked goods, and other typically high-calorie items. London-based Tate & Lyle released its proprietary variant of allulose, known as Dolcia Prima allulose, [26] and U.S.-based Anderson Global Group released its own proprietary variant into the North American market in 2015. [27] [28] The first major food company to adopt allulose as a sweetener was Quest Nutrition in some of their protein bar products. [17]
On April 16, 2019, US Food and Drug Administration (FDA) issued a draft guidance, allowing food manufacturers to exclude allulose from total and added sugar counts on Nutrition and Supplement Facts labels. [29] Like sugar alcohols and dietary fiber, allulose will still count towards total carbohydrates on nutrition labels. [29] This, combined with the GRAS designation, has increased interest in including allulose in food products instead of sucrose.
A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 and thus with the empirical formula Cm(H2O)n, which does not mean the H has covalent bonds with O. However, not all carbohydrates conform to this precise stoichiometric definition, nor are all chemicals that do conform to this definition automatically classified as carbohydrates.
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose, lactose, and maltose. White sugar is a refined form of sucrose. In the body, compound sugars are hydrolysed into simple sugars.
Sucralose is an artificial sweetener and sugar substitute. As the majority of ingested sucralose is not metabolized by the body, it adds very little food energy. In the European Union, it is also known under the E number E955. It is produced by chlorination of sucrose, selectively replacing three of the hydroxy groups—in the C1 and C6 positions of the fructose portion and the C4 position of the glucose portion—to give a 1,6-dichloro-1,6-dideoxyfructose–4-chloro-4-deoxygalactose disaccharide. Sucralose is about 600 times sweeter than sucrose, 3 times as sweet as both aspartame and acesulfame potassium, and 2 times as sweet as sodium saccharin.
Splenda is a global brand of sugar substitutes and reduced-calorie food products. While the company is known for its original formulation containing sucralose, it also manufactures items using natural sweeteners such as stevia, monk fruit and allulose. It is owned by the American company Heartland Food Products Group. The high-intensity sweetener ingredient sucralose used in Splenda Original is manufactured by the British company Tate & Lyle.
Fructose, or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed by the gut directly into the blood of the portal vein during digestion. The liver then converts most fructose and galactose into glucose for distribution in the bloodstream or deposition into glycogen.
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula C
12H
22O
11.
A sugar substitute is a food additive that provides a sweetness like that of sugar while containing significantly less food energy than sugar-based sweeteners, making it a zero-calorie or low-calorie sweetener. Artificial sweeteners may be derived through manufacturing of plant extracts or processed by chemical synthesis. Sugar substitute products are commercially available in various forms, such as small pills, powders, and packets.
Corn syrup is a food syrup which is made from the starch of corn/maize and contains varying amounts of sugars: glucose, maltose and higher oligosaccharides, depending on the grade. Corn syrup is used in foods to soften texture, add volume, prevent crystallization of sugar, and enhance flavor. It can be processed into high-fructose corn syrup (HFCS) by using the enzyme D-xylose isomerase to convert a large proportion of its glucose into sweeter fructose.
In chemistry, a hexose is a monosaccharide with six carbon atoms. The chemical formula for all hexoses is C6H12O6, and their molecular weight is 180.156 g/mol.
Inulins are a group of naturally occurring polysaccharides produced by many types of plants, industrially most often extracted from chicory. The inulins belong to a class of dietary fibers known as fructans. Inulin is used by some plants as a means of storing energy and is typically found in roots or rhizomes. Most plants that synthesize and store inulin do not store other forms of carbohydrate such as starch. In the United States in 2018, the Food and Drug Administration approved inulin as a dietary fiber ingredient used to improve the nutritional value of manufactured food products. Using inulin to measure kidney function is the "gold standard" for comparison with other means of estimating glomerular filtration rate.
In organic chemistry, a ketose is a monosaccharide containing one ketone group per molecule. The simplest ketose is dihydroxyacetone, which has only three carbon atoms. It is the only ketose with no optical activity. All monosaccharide ketoses are reducing sugars, because they can tautomerize into aldoses via an enediol intermediate, and the resulting aldehyde group can be oxidised, for example in the Tollens' test or Benedict's test. Ketoses that are bound into glycosides, for example in the case of the fructose moiety of sucrose, are nonreducing sugars.
Erythritol (, ) is an organic compound, the naturally occurring achiral meso four-carbon sugar alcohol (or polyol). It is the reduced form of either D- or L-erythrose and one of the two reduced forms of erythrulose. It is used as a food additive and sugar substitute. It is synthesized from corn using enzymes and fermentation. Its formula is C
4H
10O
4, or HO(CH2)(CHOH)2(CH2)OH.
Tagatose is a hexose monosaccharide. It is found in small quantities in a variety of foods, and has attracted attention as an alternative sweetener. It is often found in dairy products, because it is formed when milk is heated. It is similar in texture and appearance to sucrose :215 and is 92% as sweet,:198 but with only 38% of the calories.:209 Tagatose is generally recognized as safe by the Food and Agriculture Organization and the World Health Organization, and has been since 2001. Since it is metabolized differently from sucrose, tagatose has a minimal effect on blood glucose and insulin levels. Tagatose is also approved as a tooth-friendly ingredient for dental products. Consumption of more than about 30 grams of tagatose in a dose may cause gastric disturbance in some people, as it is mostly processed in the large intestine, similar to soluble fiber.:214
High-fructose corn syrup (HFCS), also known as glucose–fructose, isoglucose and glucose–fructose syrup, is a sweetener made from corn starch. As in the production of conventional corn syrup, the starch is broken down into glucose by enzymes. To make HFCS, the corn syrup is further processed by D-xylose isomerase to convert some of its glucose into fructose. HFCS was first marketed in the early 1970s by the Clinton Corn Processing Company, together with the Japanese Agency of Industrial Science and Technology, where the enzyme was discovered in 1965.
Isomaltulose is a disaccharide carbohydrate composed of glucose and fructose. It is naturally present in honey and sugarcane extracts and is also produced industrially from table sugar (sucrose) and used as a sugar alternative.
Agave syrup, also known as maguey syrup or agave nectar, is a sweetener commercially produced from several species of agave, including Agave tequilana and Agave salmiana. Blue-agave syrup contains 56% fructose as a sugar providing sweetening properties.
Critics and competitors of high-fructose corn syrup (HFCS), notably the sugar industry, have for many years used various public relations campaigns to claim the sweetener causes certain health conditions, despite the lack of scientific evidence that HFCS differs nutritionally from sugar. The HFCS industry has tried to respond to these campaigns with their own efforts.
Isomaltooligosaccharide (IMO) is a mixture of short-chain carbohydrates which has a digestion-resistant property. IMO is found naturally in some foods, as well as being manufactured commercially. The raw material used for manufacturing IMO is starch, which is enzymatically converted into a mixture of isomaltooligosaccharides.
Added sugars or free sugars are sugar carbohydrates added to food and beverages at some point before their consumption. These include added carbohydrates, and more broadly, sugars naturally present in honey, syrup, fruit juices and fruit juice concentrates. They can take multiple chemical forms, including sucrose, glucose (dextrose), and fructose.