Enzymatically modified stevia is a type of sweetener that comes from the stevia plant, Stevia rebaudiana. This modified form is designed to enhance the taste profile of stevia-based sweeteners, making them more appealing for use in various food and beverage products. The primary goal of this modification is to provide a sweetening solution that closely resembles sugar while addressing some inherent taste challenges of natural stevia extracts.
Natural Stevia and Its Challenges
Natural stevia is derived from the leaves of the Stevia rebaudiana plant, native to South America, particularly Paraguay and Brazil, where it has been used for centuries as a sweetener and in traditional medicine. The sweetness of the plant comes from compounds called steviol glycosides, which are found in its leaves. Common steviol glycosides include stevioside and rebaudioside A (Reb A).
While these compounds offer intense sweetness, often 200 to 400 times sweeter than table sugar, natural stevia extracts frequently present a bitter aftertaste or licorice-like notes. This bitterness can be off-putting to consumers and limits its use in many applications. The challenge lies in minimizing these undesirable sensory characteristics while retaining the high sweetness and natural origin of stevia.
How Enzymatic Modification Works
Enzymatic modification addresses the taste challenges of natural stevia by using enzymes to transform existing steviol glycosides into other, more desirable forms. This process typically involves enzymes like cyclomaltodextrin-glucanotransferase (CGTase) or UDP-glucosyltransferase. These enzymes catalyze the addition of glucose units to the steviol glycoside structure, for example, converting Reb A into rebaudioside M (Reb M) or rebaudioside D (Reb D).
The addition of these glucose units alters the chemical structure of the steviol glycosides, which in turn changes how they interact with taste receptors, leading to a cleaner, more sugar-like taste. This enzymatic process mimics natural biological transformations, making the modified stevia a naturally derived ingredient.
Advantages of Modified Stevia
Enzymatically modified stevia offers several advantages over traditional stevia extracts, primarily centered on an improved taste profile. The modification significantly reduces or eliminates the bitter aftertaste often associated with natural stevia, providing a sweetness that more closely resembles sugar.
Beyond taste, modified stevia can exhibit increased solubility, which is beneficial for its incorporation into various food and beverage formulations, particularly liquids. The improved taste and solubility mean that higher levels of sugar replacement can be achieved without compromising flavor or texture. Additionally, certain modified stevia compounds, like Reb M, can be perceived as having a sweetness intensity comparable to sucrose, even at lower concentrations.
Safety and Common Uses
Enzymatically modified stevia has undergone rigorous safety assessments by regulatory bodies around the world. In the United States, it is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA). This GRAS status indicates its safety for food applications. Similarly, in the European Union, enzymatically converted stevia, such as Reb M, has been approved for use, with the European Food Safety Authority (EFSA) concluding that its acceptable daily intake is consistent with other steviol glycosides.
Enzymatically modified stevia can be found in a variety of products, including soft drinks, dairy items like yogurt, baked goods, cereals, and sports nutrition products. It is also commonly used in tabletop sweeteners, providing a versatile, calorie-free option for consumers seeking to reduce sugar intake.