A considerable quantity of mannitol is produced during fermentation of kimchi, a Korean pickled vegetable. As the fermentation proceeds, glucose, fructose and mannose are liberated from cabbage or radish and most of the free sugars are transformed into mannitol. The maximum amount of mannitol produced is around 4-5 g per kg kimchi at 25 degrees C. Fructooligosaccharides added play an important role in mannitol production during the fermentation of kimchi.