Stevia rebaudiana Bertoni is an ancient perennial shrub of South American used since ancient times for various purposes throughout the world. Stevia extracts contain high levels of sweetening compounds called steviol glycosides which besides sweetening (300 times sweeter than sacarose) possess antioxidant, antimicrobial and antifungal activity. Stevioside and rebaudioside A are the main sweetening compounds of this plant which are thermostable even at temperatures of up to 200 °C, making them suitable for use in cooked foods. Preparations of steviol glycosides are reported to be used principally as sweeteners in fruit and milk-based drinks, desserts, yoghurts, confectioneries, and pickles. The use of Stevia extract as a table-top sweetener is well known. The leaves of Stevia has functional and sensory properties superior to those of many other high-potency sweeteners and is likely to become a major source of safe and high-potency sweetener for the growing natural food market in the future.​