Trehalose is a naturally occurring sugar that has become relevant in modern food science due to its unique chemical properties and growing use in processed foods. As a disaccharide, it is formed from two molecules of glucose, but it behaves differently from common table sugar, or sucrose. This carbohydrate is found naturally in a variety of organisms where it performs a protective function, but it is now manufactured commercially as a versatile food ingredient. Understanding its structure, manufacturing uses, and how the human body processes it clarifies its role in the contemporary diet.
The Structure and Natural Sources of Trehalose
Trehalose is chemically defined by the unusual alpha, alpha-1,1-glycosidic linkage connecting its two glucose units. This specific linkage makes the molecule a non-reducing sugar, differentiating it from common sugars like sucrose. This structure contributes to high stability, making it resistant to breakdown by heat and acid, which is advantageous in food processing.
This disaccharide is widely distributed in nature, synthesized by organisms such as bacteria, fungi, plants, and invertebrates. It is found in high concentrations in baker’s yeast, certain mushrooms, and sea algae. In these organisms, it acts as a stress protectant, allowing them to survive extreme environmental conditions like desiccation and freezing by stabilizing cellular components.
Functional Applications in Food Manufacturing
In food manufacturing, trehalose is primarily used not for its sweetness, which is only about 45% that of sucrose, but for its functional properties. One main application is as a protein stabilizer, preventing the denaturation of proteins during processes like freezing, thawing, and drying. This helps preserve the natural structure of proteins and enzymes, benefiting frozen desserts and prepared frozen meals.
Trehalose also functions as a cryoprotectant and humectant, maintaining the quality and texture of food products. As a cryoprotectant, it inhibits the formation of large ice crystals in frozen foods, preventing textural damage and preserving flavor integrity. Its humectant properties allow it to bind water, helping baked goods retain moisture and softness over time, extending shelf life. Furthermore, its non-reducing nature means it resists the Maillard reaction, which causes non-enzymatic browning, thus maintaining the color and appearance of certain foods during heat processing.
Digestion, Metabolism, and Glycemic Impact
The human body processes trehalose in the small intestine, requiring a specific enzyme called trehalase for breakdown. This enzyme, located on the brush border of the intestinal lining, hydrolyzes the alpha, alpha-1,1-glycosidic bond, splitting trehalose into its two constituent glucose units. The resulting glucose is then absorbed into the bloodstream like any other sugar.
Compared to sucrose, which is rapidly hydrolyzed by the sucrase enzyme, the digestion of trehalose by trehalase is slower. This difference in the rate of breakdown and subsequent absorption leads to a more gradual release of glucose into the blood.
Due to this slower process, trehalose has a lower glycemic index (GI) and causes a less immediate spike in blood glucose and insulin levels than standard table sugar. Studies show that blood glucose and insulin peaks are significantly lower after consuming trehalose compared to an equivalent amount of glucose.
This attenuated response is why it is regarded as a sugar that supports better blood sugar management, even though it provides nearly the same caloric content as sucrose, at approximately 4 kilocalories per gram. The slower metabolic effect may be beneficial for individuals monitoring their blood sugar.
Consumer Labeling and Regulatory Status
In the United States, trehalose has been determined to be Generally Recognized As Safe (GRAS) by the Food and Drug Administration (FDA). This designation allows it to be used as a food ingredient, and the FDA has reviewed notifications for its use in a wide variety of food categories, including baked goods, beverages, dairy products, and frozen desserts.
When checking a product label, trehalose is typically listed simply by its name, “Trehalose,” in the ingredient list. From a nutritional labeling standpoint, it is classified as a carbohydrate and is counted under the “Sugars” subcategory on the Nutrition Facts panel, as it is a disaccharide that the body breaks down into glucose.