What is Trehalose?
Trehalose is a disaccharide, or a double sugar, formed from two molecules of glucose joined by a unique alpha-1,1 glycosidic bond. Unlike table sugar (sucrose), this specific linkage gives trehalose exceptional stability, making it resistant to heat and acid and preventing it from participating in the Maillard browning reactions during baking. This stability is crucial to its function in nature and its various industrial applications. Found in many life forms—including certain plants, insects, fungi like mushrooms, and yeast—trehalose acts as a cellular protectant, shielding against environmental stressors like heat, cold, and dehydration. In the food industry, this function is harnessed to preserve the texture, color, and flavor of products, and to extend their shelf life.
Where is trehalose found naturally?
Trehalose exists naturally across the biological world, demonstrating its ancient and vital role as a protective molecule.
- Fungi: A common dietary source is mushrooms, which can contain a significant percentage of trehalose by dry weight.
- Plants: It is found in certain plants that can withstand severe dehydration, such as the 'resurrection plant' (Selaginella lepidophylla).
- Invertebrates: Many insects, including bees, use trehalose as their primary blood sugar for energy. Tardigrades (water bears), renowned for their ability to survive in extreme conditions, utilize trehalose as a protective agent.
- Seafood: Some shellfish also contain naturally occurring trehalose.
Industrial applications of trehalose
The unique properties of trehalose, including its high stability and moisture-retaining capacity, make it an extremely valuable ingredient in commercial products.
- Food and Beverage: Trehalose is used as a natural sweetener, texturizer, and stabilizer. It is only about 45% as sweet as sucrose and provides a balanced flavor profile. Its low hygroscopicity means it resists absorbing moisture, which is ideal for dry goods like cookies and candies. As a cryoprotectant, it prevents ice crystal formation in frozen foods, improving texture in items like ice cream and frozen dough.
- Cosmetics: In skincare, trehalose is a powerful humectant, a substance that attracts and retains moisture. It helps protect the skin from dehydration and environmental damage, and is used in moisturizers, serums, and masks.
- Pharmaceutical and Biomedical: The stabilizing effects of trehalose are leveraged to preserve sensitive biological materials. It is used in the cryopreservation (freezing) of cells, tissues, and vaccines, and as a stabilizer for enzymes and other proteins.
- Industrial Protection: Beyond food and health, trehalose's protective abilities are used in materials science for things like functional fiber coatings for textiles and in the preservation of cultural artifacts.
Trehalose vs. Sucrose: A Comparison
| Feature | Trehalose | Sucrose (Table Sugar) |
|---|---|---|
| Sweetness | Approximately 45% of sucrose's sweetness. | The benchmark for sweetness. |
| Glycemic Index | Low GI, leading to a slower and steadier blood sugar response. | High GI, causing rapid blood sugar spikes. |
| Chemical Structure | Non-reducing disaccharide, composed of two glucose molecules. | Non-reducing disaccharide, composed of one glucose and one fructose molecule. |
| Stability | Highly stable under heat and acidic conditions; resistant to Maillard browning. | Less stable under acidic and high-heat conditions; participates in Maillard browning. |
| Functional Role | Excellent bioprotectant; acts as a stabilizer and humectant. | Primary use is as a sweetener; also provides bulk. |
| Digestion | Slowly hydrolyzed into glucose by the enzyme trehalase. | Quickly hydrolyzed into glucose and fructose. |
Potential health benefits of trehalose
Researchers are investigating trehalose's potential health impacts, focusing on its unique metabolic properties and its ability to trigger cellular processes.
- Autophagy Activation: Trehalose has been shown to activate autophagy, a cellular process that removes damaged cells and protein aggregates. This has led to research exploring its potential role in neurodegenerative diseases like Alzheimer's and Parkinson's.
- Glucose and Lipid Metabolism: Studies in animal models suggest trehalose can improve glucose homeostasis and lipid metabolism, which could benefit cardiometabolic health and help manage conditions like hepatic steatosis (fatty liver disease).
- Antioxidant Properties: Its ability to help reduce inflammation and oxidative stress provides protection for cells throughout the body.
Safety and potential concerns
Trehalose is widely considered safe by regulatory bodies such as the U.S. FDA and Health Canada. However, some considerations are worth noting.
- Digestive Issues: In rare cases, individuals with a trehalase deficiency may experience gastrointestinal discomfort, such as bloating and diarrhea, after consuming trehalose. This deficiency is much less common than lactose intolerance.
- C. difficile Link: A highly publicized 2018 Nature paper linked trehalose consumption to the rise of virulent C. difficile strains. However, subsequent research and epidemiological evidence have largely refuted this claim, showing no correlation between trehalose usage and the outbreaks. The overall consensus is that trehalose is safe for consumption.
Conclusion
In summary, what is trehalose in English? It is a remarkable, naturally occurring sugar composed of two glucose molecules that offers much more than simple sweetness. Its unique cellular protective capabilities, high stability, and moisture-retaining properties have secured its place as a valued ingredient across food, cosmetic, and pharmaceutical industries. Beyond its industrial uses, ongoing research continues to unveil potential health benefits related to cellular function and metabolism, though further clinical validation is needed. Overall, trehalose is a safe and versatile compound, providing a host of advantages far beyond what one might expect from a simple sugar.
