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IUPAC name
Other names
23140-52-5 N
ChEBI CHEBI:27605 YesY
ChemSpider 81254 YesY
Jmol-3D images Image
MeSH psicose
PubChem 90008
Molar mass 180.16 g·mol−1
Melting point 58 °C (136 °F; 331 K) [1]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

D-Psicose (D-allulose, D-ribo-2-hexulose, C6H12O6) is a low-energy monosaccharide sugar. Psicose (allulose) is one of many sugars that exist in nature. First identified in wheat more than 70 years ago, psicose is a C-3 epimer of D-fructose, and is present in small quantities in agricultural products and commercially prepared carbohydrate complexes. It is found in small quantities in certain fruits including jackfruit, figs and raisins, and in foods such as caramel sauce, maple syrup, and brown sugar.[2] The sweetness of psicose is 70% of the sweetness of sucrose.[3]

Psicose has been reviewed by the U.S. Food and Drug Administration (FDA) and is generally recognized as safe (GRAS).[4] It can be used in foods and beverages as a low-calorie sugar substitute in a variety of food products, including beverages, yogurt, ice cream, and baked products. It provides the taste and texture of sugar and can reduce the amount of calories consumed from sugar by 90%.

A study consisting of eight healthy adults who consumed 15 grams of unlabeled psicose with 776 nCi of 14C-psicose showed that it was not significantly metabolized. Results show the majority (86%) of the radioactive dose was excreted in the urine.[5] Results of this study supported by Tate and Lyle show that psicose is not metabolized, thus its caloric value is insignificant. Consumers who are monitoring their caloric intake can benefit from psicose because it contains a small amount of food energy.

Psicose can benefit consumers who monitor their sugar intake because it does not impact the glycemic response significantly. A study showed that when 25 grams of psicose were ingested compared to 25 grams of sugar, psicose did not raise blood sugar levels above the baseline for two hours after ingestion.[6] [7]

Psicose can be incorporated into food and beverages so they taste the same as full-sugar versions, maintaining the taste and texture that people expect from these foods, but with fewer calories. It also can be used in combination with sweeteners to make products that are already low in calories taste even better.

The first mass-production method for psicose was established when Ken Izumori at Kagawa University in Japan discovered the key enzyme, D-tagatose 3-epimerase, to convert fructose to D-psicose in 1994.[8][9] This method of production has a high yield, but suffers from a very high production cost, in the hands of the Kagawa research group.


  1. ^ David R. Lide, G.W.A. Milne, ed. (December 30, 1993). CRC Handbook of Data on Organic Compounds (3rd ed.). CRC Press. p. 4596. 
  2. ^ Miller BS, Swain T. Chromatographic analysis of the free amino acids, organic acids and sugars in wheat plant extracts. J Sci Food Agric. 1960;11:344–348.
  3. ^ Chung MY, Oh DK, Lee KW. Hypoglycemic health benefits of D-psicose. J Agric Food Chem. 2012, 60:863-869.
  4. ^ FDA: U.S. Food and Drug Administration generally recognized as safe(GRAS)notice;
  5. ^ Kendall C, Wolever T, Vuksan V, Jenkins AJ, Campbell J. Comparison of glycemic responses elicited by 25g glucose, 25g allulose. 2014. Glycemia Consulting Inc. Toronto, ON, Canada
  6. ^ Chung MY, Oh DK, Lee KW. Hypoglycemic health benefits of D-psicose. J Agric Food Chem. 2012, 60:863-869.
  7. ^ Wolever T, Jenkins AJ. A Randomized, Controlled, Crossover Study to Assess the Effects of a Sweetener on Postprandial Glucose and Insulin Excursions in Healthy Subjects. 2015. Glycemic Index Labs. Toronto, ON, Canada.
  8. ^ Itoh H, Okaya H, Khan AR, Tajima S, Hayakawa S, Izumori K (1994). "Purification and characterization of D-tagatose 3-epimerase from Pseudomonas sp. ST-24". Biosci Biotechnol Biochem. 58: 2168–2171. doi:10.1271/bbb.58.2168. 
  9. ^ Itoh H, Sato T, Izumori K (1995). "Preparation of d-psicose from d-fructose by immobilized d-tagatose 3-epimerase." J Fermentation and Bioengineering 80(1): 101–103.