psicose

The sweetness of allulose is estimated to be 70% of the sweetness of sucrose.{{cite journal |last1=Chung |first1=Min-Yu |last2=Oh |first2=Deok-Kun |last3=Lee |first3=Ki Won |title=Hypoglycemic Health Benefits of d -Psicose |journal=Journal of Agricultural and Food Chemistry |date=February 2012 |volume=60 |issue=4 |pages=863–869 |doi=10.1021/jf204050w |pmid=22224918 }}{{cite book|author=Karl F. Tiefenbacher|title=The Technology of Wafers and Waffles I: Operational Aspects|url=https://books.google.com/books?id=jysUDgAAQBAJ&pg=PA182|date=16 May 2017|publisher=Elsevier Science|isbn=978-0-12-811452-0|pages=182–}} It has some cooling sensation and no bitterness. Its taste is said to be sugar-like, in contrast to certain other sweeteners, like the high-intensity sugar substitutes aspartame and saccharin. 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. In rats, the relative energy value of allulose was found to be 0.007 kcal/g, or approximately 0.3% of that of sucrose. Similar to the sugar alcohol erythritol, allulose is minimally metabolized and is excreted largely unchanged. The glycemic index of allulose is very low or negligible.

Allulose is a weak inhibitor of the enzymes α-glucosidase, α-amylase, maltase, and sucrase. Because of this, it can inhibit the metabolism of starch and disaccharides into monosaccharides in the gastrointestinal tract. Additionally, allulose inhibits the absorption of glucose via transporters in the intestines. For these reasons, allulose has potential antihyperglycemic effects, and has been found to reduce postprandial hyperglycemia in humans.{{cite journal |last1=Lê |first1=Kim-Anne |last2=Robin |first2=Frédéric |last3=Roger |first3=Olivier |title=Sugar replacers: from technological challenges to consequences on health |journal=Current Opinion in Clinical Nutrition & Metabolic Care |date=July 2016 |volume=19 |issue=4 |pages=310–315 |doi=10.1097/MCO.0000000000000288 |pmid=27168355 |s2cid=5300107 }} Through modulation of lipogenic enzymes in the liver, allulose may also have antihyperlipidemic effects.

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. The maximum non-effect dose of allulose in causing diarrhea in humans has been found to be 0.55 g/kg of body weight. 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).{{cite journal |last1=Mäkinen |first1=Kauko K. |title=Gastrointestinal Disturbances Associated with the Consumption of Sugar Alcohols with Special Consideration of Xylitol: Scientific Review and Instructions for Dentists and Other Health-Care Professionals |journal=International Journal of Dentistry |date=2016 |volume=2016 |pages=1–16 |doi=10.1155/2016/5967907 |pmid=27840639 |pmc=5093271 |doi-access=free }}{{cite book|author1=Kay O'Donnell|author2=Malcolm Kearsley|title=Sweeteners and Sugar Alternatives in Food Technology|url=https://books.google.com/books?id=3Mnwdwx2xDgC&pg=PT322|date=13 July 2012|publisher=John Wiley & Sons|isbn=978-1-118-37397-2|pages=322–}}{{cite book|author1=Kathleen A. Meister|author2=Marjorie E. Doyle|title=Obesity and Food Technology|url=https://books.google.com/books?id=8zdeA2QZjJQC&pg=PA14|year=2009|publisher=Am Cncl on Science, Health|pages=14–|id=GGKEY:2Q64ACGKWRT}}

D-allulose was found to be more reactive than fructose and glucose in glycation reactions.{{cite journal |last1=Namli |first1=Serap |last2=Sumnu |first2=S. Gulum |last3=Oztop |first3=Mecit H. |title=Microwave glycation of soy protein isolate with rare sugar (D-allulose), fructose and glucose |journal=Food Bioscience |date=April 2021 |volume=40 |page=100897 |doi=10.1016/j.fbio.2021.100897 }}

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 incremental area under the curve (iAUC) of postprandial glucose.{{cite journal |vauthors=Braunstein CR, Noronha JC, Khan TA, Mejia SB, Wolever TM, Josse RG, Kendall CW, Sievenpiper JL |title=Effect of fructose and its epimers on postprandial carbohydrate metabolism: A systematic review and meta-analysis |journal=Clinical Nutrition |date=November 2020 |volume=39 |issue=11 |pages=3308–3318 |doi=10.1016/j.clnu.2020.03.002 |pmid=32220498 |doi-access=free }} The quality of the evidence was rated as moderate.

File:D-Psicose Haworth.svg of D-psicose]]

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.{{cite journal |last1=Mu |first1=Wanmeng |last2=Zhang |first2=Wenli |last3=Feng |first3=Yinghui |last4=Jiang |first4=Bo |last5=Zhou |first5=Leon |title=Recent advances on applications and biotechnological production of d-psicose |journal=Applied Microbiology and Biotechnology |date=June 2012 |volume=94 |issue=6 |pages=1461–1467 |doi=10.1007/s00253-012-4093-1 |pmid=22569636 |s2cid=15940502 }} It is a C3 epimer of fructose. Fructose can be converted to allulose by the enzymes D-tagatose 3-epimerase ({{EC number|5.1.3.31}}) and/or D-psicose 3-epimerase ({{EC number|5.1.3.30}}), which has allowed for mass production of allulose. The compound is found naturally in trace amounts in wheat, figs, raisins, maple syrup, and molasses. Allulose has similar physical properties to those of regular sugar, such as bulk, mouthfeel, browning capability, and freeze point depression. This makes it favorable for use as a sugar replacement in food products, including ice cream.

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.{{cite journal |doi-access=free |doi=10.2903/j.efsa.2021.6565 |journal=EFSA Journal |volume=19 |issue=4 |date=30 April 2021 |title=Safety evaluation of the food enzyme d-psicose 3-epimerase from the genetically modified Escherichia coli strain K-12 W3110 (pWKLP) |author=Claude Lambré |author2=José Manuel Barat Baviera |display-authors=etal|hdl=10251/185436 |hdl-access=free }} 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.

Allulose was first discovered in the 1940s. 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.{{Cite journal |last1=Itoh |first1=Hiromichi |last2=Okaya |first2=Hiroaki |last3=Khan |first3=Anisur Rahman |last4=Tajima |first4=Shigeyuki |last5=Hayakawa |first5=Shigeru |last6=Izumori |first6=Ken |display-authors=3 |year=1994 |title=Purification and characterization of D-tagatose 3-epimerase from Pseudomonas sp. ST-24 |journal=Biosci Biotechnol Biochem |volume=58 |issue=12 |pages=2168–2171 |doi=10.1271/bbb.58.2168 }}{{cite journal |last1=Itoh |first1=Hiromichi |last2=Sato |first2=Tomoko |last3=Izumori |first3=Ken |title=Preparation of d-psicose from d-fructose by immobilized d-tagatose 3-epimerase |journal=Journal of Fermentation and Bioengineering |date=January 1995 |volume=80 |issue=1 |pages=101–103 |doi=10.1016/0922-338X(95)98186-O }} 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. In June 2014, a similar GRAS letter was issued to Matsutani Chemical Industry Company, Ltd. of Japan. Non-GMO allulose manufactured by Samyang Corp. of South Korea was approved as GRAS in March 2020.{{Cite web|title=GRAS Notice GRN 000828|url=https://www.fda.gov/media/137310/download}}

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".

Allulose is not currently approved in Canada, the EU or UK.{{cite news |last1=Corbyn |first1=Zoe |title=The quest to find healthy and cheap sweeteners |url=https://www.bbc.com/news/business-67448897# |work=BBC |date=15 December 2023}}{{cite web |title=What You Need To Know About Allulose |url=https://health.clevelandclinic.org/what-is-allulose |website=Cleveland Clinic |date=2024-11-04}}

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.{{cite web| url=https://food.ec.europa.eu/system/files/2019-05/novel-food_sum_ongoing-app_2018-0394.pdf | title=Application for the Approval of Allulose as a Novel Food Ingredient in the European Union | date=25 April 2018}} CJ-Tereos Sweeteners of France filed for such an approval in April 2018. 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.{{cite web| url=https://www.ingredion.com/na/en-us/news-events/news/Ingredient-Companies-Create-Consortium-to-Put-Allulose-on-European-Menus1.html |title=Ingredient Companies Create Consortium to Put Allulose on European Menus |date= 29 November 2021 |publisher=Ingredion Incorporated}}

Allulose is produced by an enzymatic reaction that converts fructose into allulose. As of 2018, most commercially available allulose uses corn (maize) as the source of fructose.[https://www.fooddive.com/news/a-new-way-to-make-allulose-may-not-sweeten-the-sugars-appeal/526732/ A new way to make allulose may not sweeten the sugar's appeal] Another source of fructose is from sugar beet.{{cite web |url=https://www.savanna-ingredients.com/en/food/allulose/ |title=Allulose |access-date=2019-11-10}}

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.{{cite news|last1=Daniells|first1=Stephan|title=Rare sugar may replace sucrose for bakery and beyond|url=http://www.foodnavigator.com/Science/Rare-sugar-may-replace-sucrose-for-bakery-and-beyond|access-date=12 July 2015|publisher=Food Navigator|date=9 June 2008}}

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,{{cite web |last= Watson |first= Elaine |title= Tate & Lyle unveils Dolcia Prima allulose low-calorie-sugar: 'We believe this will change the food and beverage landscape forever' |website= foodnavigator-usa.com |publisher= William Reed Business Media SAS |date= 25 Feb 2015 |url= http://www.foodnavigator-usa.com/Suppliers2/Tate-Lyle-unveils-Dolcia-Prima-allulose-low-calorie-sugar}} and U.S.-based Anderson Global Group released its own proprietary variant into the North American market in 2015.{{cite news|last1=Gelski|first1=Jeff|title=New low-calorie sweetener to launch at I.F.T.|url=http://www.foodbusinessnews.net/articles/news_home/Supplier-Innovations/2015/06/New_lowcalorie_sweetener_to_la.aspx?ID={C0B602CE-EFF5-4686-81B7-B8382DFF113F}|access-date=12 July 2015|publisher=Food Business News|date=30 June 2015}}{{cite web|title=AllSweet|url=http://www.andersonglobalgroup.com/products/allsweet.php|publisher=Anderson Global Group}} The first major food company to adopt allulose as a sweetener was Quest Nutrition in some of their protein bar products.{{Cite web|url=https://www.chicagotribune.com/business/ct-biz-allulose-sugar-substitute-20190822-ayfcmkmol5a33jziuoguubrt7i-story.html|title = A natural sweetener with a tenth of sugar's calories. Allulose, developed in Hoffman Estates, could be 'breakthrough ingredient.'}}

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.{{Cite web|url=https://www.fda.gov/NewsEvents/Newsroom/FDAInBrief/ucm636183.htm|title=FDA In Brief - FDA In Brief: FDA allows the low-calorie sweetener allulose to be excluded from total and added sugars counts on Nutrition and Supplement Facts labels when used as an ingredient|last=Commissioner|first=Office of the|website=www.fda.gov|language=en|access-date=2019-04-17}} Like sugar alcohols and dietary fiber, allulose will still count towards total carbohydrates on nutrition labels. This, combined with the GRAS designation, has increased interest in including allulose in food products instead of sucrose.

As of April 2025, allulose is not approved as a food additive in Canada and the EU.

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{{Carbohydrates}}

Category:Ketohexoses

Category:Pyranoses

Category:Furanoses