Trehalose

Trehalose Sources

Trehalose occurs naturally in small amounts in mushrooms, honey, lobsters, shrimps, certain seaweeds (algae), wine, beer, bread and other foods produced by using baker’s or brewer’s yeast ^[3].

As a food additive, trehalose is artificially produced from corn starch using several bacterial enzymes such as alpha-amylase, obtained from Bacillus licheniformis, and isoamylase from Pseudomonas amyloderamosa ^[1,3,4]. Trehalose is heat stable and preserves the cell structure of foods after heating and freezing, so it is used as a food texturizer and stabilizer in dried foods, frozen foods, nutrition bars, fruit fillings and jams, instant noodles and rice, white chocolate, sugar coating, bakery cream, processed seafood and fruit juices ^[3,4].

Trehalose Function in the Human Body

Trehalose is a source of energy – it can provide about 4 Calories per gram, about the same as sucrose ^[3].

Trehalose Safety

In the EU ^[5] and Australia ^[3], trehalose is considered a novel food – a food that does not have a long-term history of safe use. Trehalose as a food additive is safe to use; it is Generally Recognized As Safe (GRAS) by the U.S. Food and Drug Administration (FDA) ^[6]. Trehalose is approved and commonly used in Japan, Taiwan and south Korea; it is also approved in the EU, Australia and New Zealand ^[7].

According to some laboratory studies published in Nature in January 2018, trehalose stimulates the growth of certain strains of Clostridium difficile bacteria. These bacteria can cause severe inflammation of the colon, especially in the patients treated in hospitals. In one study in mice, dietary trehalose increased the severity of the infection caused by C. difficile. More studies are needed to find out if trehalose increases the risk and severity of the infection in humans.

Trehalose Digestion

In the small intestinal lining, the enzyme trehalase breaks trehalose into two glucose molecules, which are then absorbed ^[3]. Healthy individuals can completely digest 10-50 grams of trehalose from a single meal ^[4,7]. Some individuals, especially those with irritable bowel syndrome (IBS) and digestive problems mentioned below, may be sensitive to lower amounts, though. Any undigested trehalose passes to the large intestine where normal bacteria break it down to gases and irritant substances that can cause abdominal bloating or diarrhea ^[7].

Who can benefit from avoiding/limiting trehalose intake?

Individuals with the following conditions can benefit from avoiding trehalose:

• Active celiac disease ^[4].
• Trehalase deficiency–a rare genetic disorder most common in  Greenland ^[4,8,9,10]. The yeast Saccharomyces boulardii, sold as a prebiotic, releases the enzyme trehalase, so it could theoretically help reduce symptoms in individuals with trehalase deficiency, but there is a lack of human clinical trials ^[11].
• Glucose-galactose malabsorption ^[13]
• GLUT1 deficiency syndrome ^[14]

Trehalose and Dental Caries

Trehalose has a low potency of promoting tooth decay ^[12,15].

Trehalose and Blood Glucose, Insulin and Diabetes

• Trehalose triggers only a small increase of blood insulin levels ^[2].
• Trehalose glycemic index is 72, which is relatively high ^[16-p.9].

Trehalose and Cooking

• Trehalose is a white crystalline substance, 45% as sweet as sucrose ^[1].
• Trehalose has low hygroscopicity – it does not readily absorb water ^[17].
• Trehalose solubility in water at 68 °F (20 °C) is 69 g/100 mL ^[6,18]. Trehalose is slightly soluble in ethanol ^[1].
• The melting point of trehalose dihydrate is 207 °F (97 °C) and trehalose anhydride 210.5 °C (411 °F) ^[18].
• Trehalose is a non-reducing sugar ^[1], so it does not react with amino acids to initiate the Maillard browning reaction ^[6].