 | |
| Names | |
|---|---|
| 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 |
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| ECHA InfoCard | 100.008.182 |
| MeSH | psicose |
| UNII | |
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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 theirstandard state (at 25 °C [77 °F], 100 kPa). | |
D-Psicose (C6H12O6), also known asD-allulose or simplyallulose, is anepimer offructose 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 theenzymes 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 forgenerally 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 theNutrition 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 raiseinsulin levels, but more testing may be needed to evaluate any other potential side effects.[6] In 2020, the U.S. FDA accepted the conclusion bySamyang that the maximum tolerable consumption for a 60 kg adult was 33 to 36 grams per day.[7]
Thesweetness of allulose is estimated to be 70% of the sweetness ofsucrose.[8][9] It has some cooling sensation and nobitterness.[2] Its taste is said to be sugar-like, in contrast to certain other sweeteners, like the high-intensitysugar substitutesaspartame andsaccharin.[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 thesugar alcoholerythritol, allulose is minimallymetabolized and isexcreted largely unchanged.[9] Theglycemic index of allulose is very low or negligible.[2][9]
Allulose is a weakinhibitor of theenzymesα-glucosidase,α-amylase,maltase, andsucrase.[2] Because of this, it can inhibit themetabolism ofstarch anddisaccharides intomonosaccharides in thegastrointestinal tract.[2] Additionally, allulose inhibits the absorption ofglucose viatransporters in theintestines.[2] For these reasons, allulose has potentialantihyperglycemic effects, and has been found to reducepostprandialhyperglycemia in humans.[2][10] Through modulation oflipogenicenzymes in theliver, allulose may also haveantihyperlipidemic effects.[2][10]
Due to its effect of causing incomplete absorption of carbohydrates from thegastrointestinal tract, and subsequentfermentation of these carbohydrates by intestinal bacteria, allulose can result in unpleasant symptoms such asflatulence,abdominal discomfort, anddiarrhea.[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 inglycation reactions.[15]
Ameta-analysis was conducted of the effect onpostprandial 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 incrementalarea under the curve (iAUC) of postprandial glucose.[16] The quality of the evidence was rated as moderate.[16]
Allulose, also known by itssystematic nameD-ribo-2-hexulose as well as by the nameD-psicose, is amonosaccharide and aketohexose.[2][11] It is a C3epimer offructose.[2] Fructose can be converted to allulose by theenzymesD-tagatose 3-epimerase (EC5.1.3.31) and/orD-psicose 3-epimerase (EC5.1.3.30), which has allowed formass production of allulose.[2] The compound is found naturally in trace amounts inwheat,figs,raisins,maple syrup, andmolasses.[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 theEuropean 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 ofE. 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 atKagawa 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 ofCJ CheilJedang, Inc. of South Korea that allulose isgenerally 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]
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 not currently approved in Canada, the EU or UK.[21][22]
In theEuropean 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.[23] CJ-Tereos Sweeteners of France filed for such an approval in April 2018.[23] 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.[24]
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.[25] Another source of fructose is fromsugar beet.[26]
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 ofegg white protein and the production of antioxidant substances produced through theMaillard reaction.[27]
Commercial uses of allulose includelow-calorie sweeteners in beverages, yogurt, ice cream, baked goods, and other typically high-calorie items. London-basedTate & Lyle released its proprietary variant of allulose, known as Dolcia Prima allulose,[28] and U.S.-based Anderson Global Group released its own proprietary variant into the North American market in 2015.[29][30] The first major food company to adopt allulose as a sweetener wasQuest Nutrition in some of theirprotein 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 onNutrition and Supplement Facts labels.[31] Like sugar alcohols and dietary fiber, allulose will still count towards total carbohydrates on nutrition labels.[31] This, combined with the GRAS designation, has increased interest in including allulose in food products instead of sucrose.
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