CULTIVATION AND USES OF STEVIA ( Stevia rebaudiana   Bertoni): A REVIEW

Stevia [Stevia rebaudiana Bertoni; Family Asteraceae] is a natural sweetener plant that is grown commercially in many parts of Brazil, Paraguay, Central America, Thailand, Korea, China and India. The leaves of stevia are the source of sweet glycosides. It is mainly used as a sweetener and flavor enhancer in the food and beverage industry. The chemical compound obtained from stevia is considered to be the best alternative source of sugar especially for diabetes patients. Climatic factors and agronomical practices affect the quality and quantity of yield. The concentration of stevioside in the leaves is higher when the stevia plants are grown under long days and when these plants are harvested just prior to flowering. Time of harvesting depends on land type, type of stevia and growing season. The first harvest can be done four months after planting and subsequent harvest once after every 3 months. Such medicinal plants are becoming fairly popular for the treatment of different diseases all over the world. It could be suitable for diabetic and obese persons. It also showed antibacterial, antiseptic, anti-inflammatory, anti-fertility, hypotensive, diuretic and cardiotonic properties. Stevia is a small perennial shrub that has been used for centuries as a bio-sweetener and for other medicinal purposes. In addition, alternative sweeteners offer another benefit in maintaining good dental health. S. rebaudiana sweeteners are used sparingly and there seems to be no threat to public health. Stevia has been introduced to the Kenyan market as one of the cash crops for agro-based industry. The changes in leaf yield and accumulation of stevioside in response to different environmental conditions and nutritional variations might provide some leads to develop strategies for increasing the productivity of the stevia. Quality of the stevia product depends on drying temperature; high temperatures negatively affect quality, diminishing medicinal and commercial value. Multiple global regulatory organizations have determined that consumption of high quality stevia products within recommended doses is safe for all.

Keywords
Stevia; Cultivation; Medicinal uses; Diabetes; Natural sweetener; Flavor enhancer; Glycosides