Fructose, also known as fruit sugar or levulose, is a simple ketonic monosaccharide. It has the same molecular formula as glucose (C₆H₁₂O₆) but differs in structure. Fructose is highly soluble in water and has a low glycemic index compared to glucose and sucrose, making it a preferred sweetener in certain dietary applications. In crystalline form, fructose is approximately 1.7 times sweeter than sucrose at room temperature, though its relative sweetness decreases at higher temperatures. It exhibits excellent humectant properties, helps preserve moisture in baked goods, and enhances fruit flavors in beverages.