What is D-glucose monohydrate?
D-glucose monohydrate is the hydrated form of D-glucose, a naturally occurring monosaccharide and carbohydrate. The D prefix specifies its right-handed stereoisomer, also known as dextrose, which is the most abundant and biologically active form of glucose. The monohydrate suffix indicates that each molecule of glucose is bonded with one molecule of water ($H_2O$) in its solid, crystalline state.
This simple sugar is a fundamental energy source for almost all living organisms, powering cellular metabolism and other vital functions. Commercially, it is produced by the enzymatic hydrolysis of starch, which is derived from sources such as corn, potatoes, and wheat. After hydrolysis, the glucose is purified and crystallized below 50°C to form the monohydrate version, which appears as a white crystalline or granular powder.
Key chemical characteristics
As a simple sugar, D-glucose monohydrate exhibits several important chemical properties that make it suitable for its wide range of applications:
- Solubility: It is highly soluble in water, essential for liquid applications like beverages and IV fluids.
- Sweetness: It is about 75% as sweet as sucrose, useful for controlled sweetness in food.
- Reducing Sugar: Possessing a free aldehyde group, it participates in reduction reactions, like browning in baked goods (Maillard reaction).
- Metabolism: The body quickly absorbs and metabolizes it for energy, making it ideal for rapid blood sugar boosts.
Comparison: Monohydrate vs. Anhydrous
Dextrose comes in two forms: monohydrate and anhydrous. The key difference is the presence or absence of a water molecule in their crystalline structure, impacting their properties and uses.
| Feature | D-glucose Monohydrate | Anhydrous D-glucose |
|---|---|---|
| Water Content | ~9.5% water by mass. | No water of crystallization. |
| Molecular Formula | $C6H{12}O_6·H_2O$. | $C6H{12}O_6$. |
| Molar Mass | 198.17 g/mol. | 180.16 g/mol. |
| Manufacturing Temperature | Crystallized below 50°C. | Crystallized above 50°C. |
| Taste Sensation | Slightly cooling taste. | Higher sweetness, less cooling effect. |
| Hygroscopicity | Less sensitive to moisture. | Higher moisture absorption. |
| Cost of Production | Generally less expensive. | More expensive. |
| Common Uses | Sweetener, energy source, oral pharmaceuticals excipient. | Medical injections, oral glucose tolerance tests. |
Diverse applications of D-glucose monohydrate
Its versatility makes D-glucose monohydrate crucial across industries.
Food and Beverage Industry
- Sweetener: Used in baked goods, candies, and dairy.
- Fermentation Substrate: Carbon source for yeast in brewing and winemaking.
- Preservative: Extends shelf life of canned foods.
- Energy Booster: In sports drinks for fast energy.
Pharmaceutical and Medical Industry
- Fluid and Nutrient Replenishment: Component of ORS and IV fluids to restore glucose and provide calories.
- Tableting Excipient: Binder, filler, and diluent in tablets and capsules, especially chewable ones.
- Glycemic Support: Used by diabetics to rapidly raise low blood sugar.
Other Industries
- Chemical Synthesis: Raw material for biochemicals like gluconic acid and antibiotics.
- Animal Feed: Energy supplement for livestock.
- Cosmetics: Humectant in skincare and hair products.
Conclusion
D-glucose monohydrate, a hydrated form of dextrose, is a highly versatile compound used in food, medicine, and industrial chemistry. Its solubility, moderate sweetness, and reducing sugar properties make it essential. The presence of a water molecule distinguishes it from anhydrous dextrose, affecting its physical characteristics and uses. It plays a significant role in modern products, from providing quick energy in sports drinks and IV solutions to serving as a pharmaceutical excipient.
For more technical information on the chemical properties of D-glucose monohydrate, you can consult resources like the NIH PubChem database.
