The Plant Behind the Sweetness: Stevia rebaudiana
Stevia is derived from the leaves of the Stevia rebaudiana plant. Native to South America, including Paraguay and Brazil, this plant's leaves have been used for centuries to sweeten foods and drinks. The Guaraní people called it "ka'a he'ẽ," meaning "sweet herb". The sweet compounds in the leaves are called steviol glycosides and are responsible for stevia's intense, zero-calorie sweetness.
The Industrial Process: From Leaf to Packet
Creating commercial stevia sweeteners involves an industrial process to isolate and purify the sweet compounds from the leaves. This purification is essential to remove the bitter aftertaste often present in crude stevia leaf extracts, resulting in a flavor closer to sugar.
The Extraction and Purification Journey
The process involves several steps:
- Harvesting and Drying: Stevia leaves are harvested and dried.
- Water Extraction: Dried leaves are steeped in hot water to extract steviol glycosides.
- Filtration: Leaf material is filtered, leaving a liquid extract with the sweet compounds.
- Purification: The extract is purified, often using crystallization with food-grade solvents, to concentrate specific steviol glycosides and remove bitter elements.
- Bioconversion and Fermentation: Some methods use bioconversion or fermentation to produce specific steviol glycosides like Reb M, improving taste and consistency.
- Drying: Purified steviol glycosides are dried to produce the final powder or liquid sweetener.
Types of Steviol Glycosides
Stevia's sweetness comes from various steviol glycosides, with over 40 types identified, each having a slightly different taste and sweetness level. Key commercial types include:
- Rebaudioside A (Reb A): A common, less bitter glycoside used in products like Truvia and PureVia.
- Stevioside: Another major glycoside, sometimes associated with a stronger aftertaste.
- Rebaudioside M (Reb M): Often produced via fermentation, noted for its clean, sugar-like taste.
Comparison Table: Stevia vs. Sugar
| Feature | High-Purity Stevia Leaf Extract | Standard Table Sugar (Sucrose) |
|---|---|---|
| Source | Leaves of the Stevia rebaudiana plant | Sugarcane or sugar beets |
| Calories | Zero calories | Approximately 16 calories per teaspoon |
| Glycemic Impact | No impact on blood glucose levels | Significant impact on blood glucose |
| Sweetness Intensity | 200-400 times sweeter than sugar | Standard reference for sweetness |
| Processing | Extraction and purification of steviol glycosides | Refinement of plant juice |
| Aftertaste | Can have a licorice-like or bitter aftertaste at high concentrations, though newer varieties minimize this | No aftertaste, universally recognized sweet flavor |
Regulatory Status and Safety
Regulatory bodies like the FDA and those in the European Union approve only highly purified steviol glycoside extracts for food use, deeming them generally recognized as safe (GRAS). Crude stevia leaf or whole leaves are not approved for food due to insufficient toxicological data. The safety of high-purity stevia is supported by numerous studies and global health agencies.
Conclusion
To summarize, what is stevia sweetener made out of refers to the highly purified extract of sweet compounds called steviol glycosides from the Stevia rebaudiana plant. This process transforms the plant's leaves into a zero-calorie sweetener used globally in thousands of products. High-purity stevia provides a safe, plant-based sugar alternative for reducing calorie intake.
Key Takeaways
- Plant-Based Origin: Stevia sweetener is derived from the leaves of the Stevia rebaudiana plant, native to South America.
- Key Compounds: Its sweetness comes from naturally occurring compounds known as steviol glycosides.
- Industrial Production: Commercial sweeteners are made by extracting and purifying the steviol glycosides from the leaves.
- High Purity: Only high-purity stevia extracts (containing at least 95% steviol glycosides) are approved for use in food.
- Zero Calories: Steviol glycosides are not metabolized by the human body, so they provide zero calories.
- Global Approval: High-purity stevia extract is approved as a food additive in over 150 countries.
- Multiple Glycosides: There are many types of steviol glycosides, with Reb A and Reb M being the most common in commercial products.
Outbound Link
For more information on the history and modern uses of stevia, you can visit the comprehensive Wikipedia article on the topic: https://en.wikipedia.org/wiki/Stevia.
FAQs
Q: Is stevia a natural sweetener? A: Yes, stevia has a natural origin as it is extracted from the leaves of the Stevia rebaudiana plant. However, the final product is a highly purified extract, not the whole leaf.
Q: What is the difference between raw stevia leaf and stevia sweetener? A: Raw stevia leaf is simply the dried and crushed plant material, which contains many compounds and can have a bitter taste. Stevia sweetener is a highly purified extract of the sweet-tasting steviol glycosides, with the bitter components largely removed.
Q: Can people with diabetes use stevia? A: Yes, high-purity stevia sweeteners are safe for people with diabetes. They are non-nutritive and do not impact blood glucose or insulin levels.
Q: Why does some stevia have a bitter aftertaste? A: The bitter aftertaste is often associated with the less-purified, crude extracts of the stevia leaf. Commercial sweeteners have undergone purification to minimize this, and newer fermenting methods create even less-bitter tasting glycosides.
Q: What is Reb A? A: Reb A, or Rebaudioside A, is one of the specific types of steviol glycosides extracted from the stevia leaf. It is known for its clean taste profile compared to other glycosides.
Q: Are stevia sweeteners safe? A: High-purity steviol glycoside extracts have been extensively researched and deemed safe for consumption by major regulatory bodies around the world, including the FDA.
Q: How is stevia made without using the plant? A: Some high-purity steviol glycosides, like Reb M, can be produced through bioconversion and fermentation processes without needing to cultivate large amounts of the plant. This method offers a sustainable and scalable way to produce high-quality stevia sweeteners.
