Lime is a term referring to a number of different fruits (generally citruses), both species and hybrids, which have their origin in the Himalayan region of India, and which are typically round, green to yellow in color, 3â€“6 cm in diameter, generally containing sour and acidic pulp. They are frequently associated with the lemon. Limes are often used to accent the flavors of foods and beverages. They are usually smaller than lemons, and a good source of vitamin C. Limes are grown all year round and are usually sweeter than lemons. Freeze-drying (also known as lyophilization or cryodesiccation) is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport. Freeze-drying works by freezing the material and then reducing the surrounding pressure and adding enough heat to allow the frozen water in the material to sublime directly from the solid phase to gas.