Stevia rebaudiana, often referred to as stevia, is a plant native to South America, particularly Paraguay, Argentina, and Brazil. It is recognized for its intensely sweet-tasting leaves and has become a natural, calorie-free alternative to sugar in various food and beverage products.
Understanding the Rebaudiana Plant
Stevia rebaudiana is a small shrub in the Asteraceae family, also known as the “sunflower family.” This perennial plant typically grows to 30 to 100 centimeters and features oblong, aromatic leaves arranged oppositely along its stems. It thrives in warm, humid conditions and prefers well-drained, sandy soils.
Indigenous populations, such as the Guarani people of Paraguay, have used stevia leaves for over 1,500 years, traditionally sweetening yerba mate tea and other beverages. They also incorporated it into folk medicine. The plant’s sweet components are concentrated in its leaves, which are harvested and dried for various uses.
The Sweetness of Rebaudiana
The sweetness in Stevia rebaudiana leaves comes from naturally occurring compounds called steviol glycosides. Rebaudioside A (Reb A) is a prominent one used in commercial sweeteners. These compounds are significantly sweeter than table sugar, ranging from 200 to 400 times its sweetness, yet contribute no calories.
To produce high-purity commercial sweeteners, steviol glycosides are extracted from dried stevia leaves. This involves steeping the leaves in water, followed by filtration. The liquid extract then undergoes purification, often using water or alcohol, to isolate and concentrate the steviol glycosides, resulting in a naturally sourced, high-intensity sweetener.
Applications of Rebaudiana Sweeteners
Rebaudiana-derived sweeteners are widely incorporated into the food and beverage industry due to their zero-calorie profile and natural origin. They are a desirable ingredient for manufacturers seeking to reduce sugar content. These sweeteners are stable under various heat and pH levels, making them versatile for different applications, including baking and cooking.
Stevia sweeteners are found in products such as soft drinks, flavored waters, juices, dairy products like yogurts and ice cream, chewing gum, baked goods, and snack bars. It is also used in sugar-free medications, protein powders, and certain oral hygiene products.
Safety and Health Considerations
High-purity steviol glycosides from rebaudiana have received regulatory approvals from major health organizations worldwide, including the United States Food and Drug Administration (FDA), the European Food Safety Authority (EFSA), and the Joint Expert Committee on Food Additives (JECFA). These purified extracts are deemed safe for use as food additives.
The Acceptable Daily Intake (ADI) for steviol glycosides is 4 milligrams per kilogram of body weight per day, expressed as steviol equivalents. This level can be consumed daily over a lifetime without appreciable health risk. High-purity stevia leaf extracts are considered safe for the general population, including children, pregnant or nursing women, and individuals with diabetes, as they do not affect blood glucose levels. Concerns about adverse effects have been linked to crude stevia extracts, not the high-purity form approved globally.