Rebaudioside is a term for a group of natural compounds, known as steviol glycosides, responsible for the sweet taste of the stevia plant. These are high-intensity, non-caloric sweeteners that provide a taste hundreds of times more potent than sugar without contributing calories. Because of this, they have become a widespread alternative to sugar in many foods and beverages.
The Source and Extraction of Rebaudioside
Rebaudioside compounds originate from the leaves of the Stevia rebaudiana plant, a shrub native to South America. The process to obtain these sweeteners begins with harvesting and drying the plant’s leaves. The sweet compounds are extracted by steeping the dried leaves in water, creating a crude extract that contains the rebaudiosides along with other plant materials.
To isolate the sweet components, the extract undergoes further purification. This process involves filtration and chromatography techniques that separate the rebaudioside molecules from the plant extract. The resulting purified extract is then dried to create a concentrated powder, yielding the high-purity stevia extracts used by the food industry.
Understanding Different Rebaudiosides
The term “rebaudioside” encompasses a family of related molecules identified by a letter, such as A, B, D, or M. These different forms are found in the stevia leaf, but they vary in their abundance and taste profile. The most commercially relevant are Rebaudioside A (Reb A), Rebaudioside D (Reb D), and Rebaudioside M (Reb M), each offering a distinct sensory experience.
Reb A was one of the first rebaudiosides to be widely commercialized and is the most abundant in the stevia leaf. While it is intensely sweet, it can have a slightly bitter or licorice-like aftertaste, especially at higher concentrations. This characteristic prompted researchers to explore the taste profiles of other, less common rebaudiosides.
In contrast, Reb M and Reb D are found in much smaller quantities in the stevia leaf, with Reb M accounting for less than 0.1% of the glycosides. Despite their rarity, they are highly valued because their taste is remarkably similar to sugar, with minimal bitterness or lingering aftertaste. Reb M is noted for its clean sweetness, making it a preferred choice for creating sugar-free products that closely mimic their full-sugar counterparts.
Health and Safety Profile
High-purity steviol glycosides, including the various forms of rebaudioside, have been evaluated by regulatory agencies globally. In the United States, the Food and Drug Administration (FDA) has designated high-purity extracts (95% purity or higher) as “generally recognized as safe” (GRAS). This status permits their use as general-purpose sweeteners in many foods and beverages, but it applies to the purified extracts, not to whole-leaf or crude stevia extracts.
The human body does not metabolize steviol glycosides, meaning they pass through the upper gastrointestinal tract without being broken down for energy. Consequently, rebaudioside is a zero-calorie sweetener. It also has a glycemic index of zero, signifying that it does not raise blood glucose or insulin levels.
This characteristic makes rebaudioside a suitable sweetener for individuals managing blood sugar, such as those with diabetes. Its lack of calories also makes it a popular ingredient for people focused on weight management or reducing sugar intake. Major health organizations have found no adverse effects associated with the consumption of high-purity stevia extracts.
Common Uses in Food and Beverages
Rebaudioside is utilized across the food and beverage industry as a sugar substitute. Its stability under heat and across various pH levels makes it a versatile ingredient. Common applications include:
- Zero-sugar soft drinks, flavored waters, and powdered drink mixes
- Dairy products, such as yogurts and ice creams
- Nutritional products like protein powders and bars
- Tabletop sweetener packets and liquids for home use
- Baked goods, often blended with other ingredients to provide bulk and texture