E968 (Erythritol ((2R,3S)-Butan-1,2,3,4-tetrol) is a naturally occurring four-carbon sugar alcohol belonging to the family of sugar alcohols also known as polyols, with no calorific value, found in many fruits and vegetables, mushrooms and in fermented foods such as soy sauce. Its caloric value is almost zero.

The calorific value of erythritol is approximately 1/20th of the calorific capacity compared to cane sugar and 1/15th of the caloric capacity compared to xylitol, The sweetness sensation of erythritol is approximately 70% of that of cane sugar.

Industrially it occurs as a fine white crystalline powder stable at high temperatures.

What it is used for and where

Food

Ingredient included in the list of European food additives as  E968.

Used as a sweetener, erythritol is widely used in a variety of food and oral hygiene products as a sugar substitute. It is frequently used in baked goods such as cakes, biscuits and biscuits at a level of up to 10% to increase baking stability and shelf life by adding softness and freshness to products. It has the prerogative of making the dough more compact. In particular, in sweets, erythritol, which crystallises quickly, provides a good glossy patina and does not absorb moisture. In candies, erythritol controls crystallisation better when combined with maltitol.

Medical
This review thoroughly analyzes the anti-diabetic and antihyperglycemic effects as well as other metabolic effects of xylitol and erythritol using articles published in PubMed since the 1960s, containing research done on experimental animals and humans (1).

Oral health studies revealed that erythritol can reduce dental plaque weight, reduce dental plaque acids, reduce counts of Streptococcus mutans in saliva and dental plaque, and reduce the risk for dental caries better than sorbitol and xylitol, resulting in fewer tooth restorations by dentist intervention (2).

Cosmetics

Erythritol acts as a moderate humectant and moisturiser on the skin and is authorised for the following functions:

Humectant. Hygroscopic compound used to minimise water loss in the skin and to prevent it from drying out by facilitating faster and greater absorption of water into the stratum corneum of the epidermis.  The epidermis is the most superficial of the three layers that make up human skin (epidermis, dermis and hypodermis) and is the layer that maintains hydration in all three layers. In turn, the epidermis is composed of five layers: horny, the most superficial, granular, spinous, shiny, and basal. Humectants have the ability to retain the water they attract from the air in the stratum corneum and have the function of moisturising the skin. They are best used before emollients, which are oil-based.

Moisturizing. This ingredient is responsible for preventing the evaporation of moisture from the skin and improving cellular activity. When exposed to cold or hot air currents, the skin absorbs water from its inner layer to compensate for the evaporated water. If the draught phenomenon persists, the stratum corneum is dry and, if at all, damaged.

Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.

Other uses

Toothpastes. Erythritol has been recognised by the American Dental Association as an alternative to traditional sugars and as part of a comprehensive programme including proper dental hygiene. 

Personal care products such as hair care, oral hygiene, skin care, soaps and bath products, deodorants.

Animal feed. Animal feeds/poultry manure.

Cosmetics. 

Safety

A study at the University of Cleveland, USA, on healthy volunteers found that erythritol intake is associated with a risk of myocardial infarction or stroke. The analysis found, after erythritol intake, an increase above the associated threshold in plasma erythritol levels and an increase in platelet reactivity indicating a potential for thrombosis (3).

Erythritol  studies

Typical optimal commercial product characteristics Erythritol 

• Molecular Formula   C₄H₁₀O₄
• Linear Formula    HOCH₂[CH(OH)]₂CH₂OH
• Molecular Weight 122.12 g/mol
• Exact Mass    122.057907
• CAS    149-32-6 10030-58-7, 188346-77-2, 868541-49-5, 882981-67-1, 1646188-83-1, 1798874-12-0, 2075830-99-6, 909878-64-4
• EC Number    205-737-3
• IUPAC  (2S,3R)-butane-1,2,3,4-tetrol
• InChI=1S/C4H10O4/c5-1-3(7)4(8)2-6/h3-8H,1-2H2/t3-,4+  
• InChl Key      UNXHWFMMPAWVPI-ZXZARUISSA-N
• SMILES   C(C(C(CO)O)O)O
• DSSTox Substance ID: DTXSID6043919
• UNII RA96B954X6
• NSC Number 760400 8099
• Beilstein/REAXYS Number 1719753
• MDL number MFCD00004710
• PubChem Substance ID 329749381

Synonyms:

• Phycitol
• Erythrite
• Erythrit
• Phycite
• Erythrol
• i-Erythritol
• (2R,3S)-butane-1,2,3,4-tetrol
• meso-1,2,3,4-Tetrahydroxybutane
• erythro-tetritol
• 1,2,3,4-Butanetetrol, (2R,3S)-rel-
• (2R,3S)-rel-Butane-1,2,3,4-tetraol
• Butanetetrol
• Mesoerythritol
• (2r,3s)-butane-1,2,3,4-tetraol
• SMR000112220
• (2S,3R)-butane-1,2,3,4-tetrol

References______________________________________________________________________

(1) Metabolic effects of the natural sweeteners xylitol and erythritol: A comprehensive review. Wölnerhanssen BK, Meyer-Gerspach AC, Beglinger C, Islam MS. Crit Rev Food Sci Nutr. 2019 Jun 16:1-13. doi: 10.1080/10408398.2019.1623757

(2) Erythritol Functional Roles in Oral-Systemic Health.  de Cock P.  Adv Dent Res. 2018 Feb;29(1):104-109. doi: 10.1177/0022034517736499.

(3) Witkowski M, Nemet I, Alamri H, Wilcox J, Gupta N, Nimer N, Haghikia A, Li XS, Wu Y, Saha PP, Demuth I, König M, Steinhagen-Thiessen E, Cajka T, Fiehn O, Landmesser U, Tang WHW, Hazen SL. The artificial sweetener erythritol and cardiovascular event risk. Nat Med. 2023 Feb 27. doi: 10.1038/s41591-023-02223-9.