Limonene is a monocyclic monoterpene that is a major component in the oil of citrus fruit peels. It is commonly found in oranges, lemons, and other citrus fruits, contributing to their characteristic aroma. Limonene is used extensively in the food and beverage industry as a flavoring agent due to its pleasant citrus scent. It also finds applications in cleaning products and cosmetics. In terms of chemical properties, limonene is a colorless liquid at room temperature with a strong smell of oranges. It is a chiral molecule, existing in two enantiomeric forms: D-limonene and L-limonene, with D-limonene being the more common form in nature. Limonene is known for its low toxicity and is generally recognized as safe (GRAS) by the FDA. Its volatility makes it an effective solvent and a potential biofuel component.