24-08-2013, 02:36 PM
Stevia
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Introduction
Stevia (/ˈstiːvɪə/, /ˈstiːvjə/ or /ˈstɛvɪə/)[1][2][3][4] is a genus of about 240 species of herbsand shrubs in the sunflower family (Asteraceae), native to subtropical and tropical regions from western North America to South America. The species Stevia rebaudiana, commonly known as sweetleaf, sweet leaf, sugarleaf, or simply stevia, is widely grown for its sweet leaves. As a sweetener and sugar substitute, stevia's taste has a slower onset and longer duration than that of sugar, although some of its extracts may have a bitter or licorice-likeaftertaste at high concentrations.
With its steviol glycoside extracts having up to 300 times the sweetness of sugar,[5] stevia has garnered attention with the rise in demand for low-carbohydrate, low-sugar food alternatives. Because stevia has a negligible effect on blood glucose, it is attractive as a natural sweetener to people on carbohydrate-controlled diets.
The availability of stevia varies from country to country. In a few countries, it has been available as a sweetener for decades or centuries; for example, stevia has been widely used for decades as a sweetener in Japan. In some countries, health concerns and political controversies have limited its availability; for example, the United States banned stevia in the early 1990s unless labeled as a dietary supplement,[6][7] but in 2008 it approved rebaudioside A extract as a food additive. Over the years, the number of countries in which stevia is available as a sweetener has been increasing. In 2011, stevia was approved for use in the EU.[8][9]
Used in treatment
High blood pressure. Some research suggests that taking 750-1500 mg per day of stevioside, a chemical compound in stevia, reduces systolic blood pressure (the upper number in a blood pressure reading) by 10-14 mmHg and diastolic blood pressure (the lower number) by 6-14 mmHg within one week of starting treatment. However, other research suggests that taking stevioside in doses up to 15 mg per kg per day does not significantly reduce blood pressure in patients with mild high blood pressure.
Diabetes. Early research suggests that 1000 mg daily of stevioside, a chemical compound in stevia, might reduce blood sugar levels after meals by 18% in people with type 2 diabetes. However, other research suggests that taking 250 mg of stevioside three times daily does not significantly affect blood sugar levels or HbA1c (a measure over blood sugar levels over time) after three months of treatment in people with type 1 or type 2 diabetes.
Preventing pregnancy.
Heartburn.
Weight loss.
Water retention.
Heart problems.
Other conditions.
Stevia is a small perennial herb belongs to the Asteraceae family of the genus Stevia. Its scientific name isStevia rebaudiana. Some commonly known names are honey leaf plant, sweet chrysanthemum, sweetleaf stevia, sugarleaf...etc.
Stevia plant grows 2-4 feet in height with slender, branched stems and flourishes well all over temperate and some parts of tropical regions. It is being cultivated as commercial crop in Japan, China, Thailand, Paraguay, and Brazil. Today, China is the leading exporter of stevia products.
Almost all the parts of the plant taste sweet; however, the sweet glycosides are typically concentrated more in its dark green serrated leaves. The Guarani Indians of Paraguay have used its leaves to sweeten drinks and foods and in various traditional medicines. In the modern times, it is widely used in foods in many parts East Asian region and South American countries.
Health benefits of stevia
Stevia herb parts are very low in calories. Parts by parts its dry leaves are roughly 40 times sweeter than sugar. The sweetness of sugar in stevia is due to several glycoside compounds includingstevioside, steviolbioside, rebaudiosides A-E, and dulcoside.
Stevioside is non-carbohydrate glycoside compound. Hence, it lack of properties that sucrose and other carbohydrates have. Stevia extracts, like rebaudioside-A, are found to be 300 times sweeter than sugar. In contrast to sugar, however, stevia extracts have several unique properties such as long shelf life, high temperature tolerance, non-fermentative; but contain near-zero calories.