Stevia is a plant extract commonly used as an alternative sweetener for people who want to reduce their sugar intake or manage diabetes. It is significantly sweeter than sugar but contains zero calories and has a negligible effect on blood sugar levels.
Stevia is derived from the leaves of the Stevia rebaudiana plant, native to South America. Stevia is available in various forms, including liquid extracts, powdered extracts, and granulated blends, and is used to sweeten a wide range of foods and beverages.
Stevia is produced by extracting sweet compounds from the leaves of the Stevia rebaudiana plant. The leaves are harvested, dried, and steeped in water. This water extract is then filtered to remove impurities and other plant components. The resulting liquid extract is then further processed to isolate sweet compounds known as steviol glycosides. These steviol glycosides are then dried and powdered to create the final stevia product. Some stevia products may undergo additional refining processes to remove residual flavors or aftertaste.
Here is an example formulation table for stevia sweetener with the composition of ingredients:
Rebaudioside A is the sweetest and most stable steviol glycoside. The sweetener can be improved further by adding sugarcane-derived extracts and specific auxiliary additives to transglucosylated stevia sweeteners.
Here is an example formulation table for high-fiber cookies with the composition of ingredients:
The heat endurance of stevioside and its compatibility with other ingredients makes it suitable to use under various operating conditions, including high-temperature processing. In this formulation, stevioside also reduces soybean dietary fiber’s off-putting smell.
Here is an example formulation table for a carbonated drink with the composition of ingredients:
Here is an example formulation table for sugar-free chocolate with the composition of ingredients:
The leaves of stevia are about 30 times sweeter than sucrose, whereas the compounds called steviol glycosides isolated from the leaves of stevia are 200–300 times sweeter. There are 11 major steviol glycosides, as shown in the table below, of which rebaudioside A and stevioside are the most abundant.
Glucosylated steviol glycosides (GSG) are a mixture of larger glycosides of steviol derived by glucosylation of steviol glycosides extracted from leaves of the Stevia rebaudiana Bertoni plant.
Steviol glycosides have carbohydrate molecules attached to a central steviol (terpenoid) moiety. Naturally occurring steviol glycosides such as stevioside and rebaudioside A can be modified by allowing an alpha-glucosyltransferase to react on an aqueous solution containing one or more steviol glycosides and a glucose donor such as starch or cyclodextrin whereby one or more glucose units are transferred from the glucose donor to the steviol glycoside.
Modified stevoil products can provide an improved sensory experience. For example, in the case of rebaudioside A, the bitterness, aftertaste, and astringency can be decreased.
Steviol glycosides generally have a slower onset and longer sweetness duration than sugar. Each steviol glycoside has a slightly different flavor. For example, stevioside has a slight herbal taste, rebaudioside-A has a clean taste, and other minor steviol glycosides have a bitter or licorice-like aftertaste. Some people find the lingering sweetness and bitter taste to be less desirable. The composition of the steviol glycoside mixtures may differ according to the cultivar from which the steviol glycosides are extracted and the manufacturing process. The following table provides in-depth information about the sensory properties of stevia.
Off-taste can be addressed by blending steviosides with other nutritive and nonnutritive sweeteners. Synergistic use can also improve functional, processing, cost, and stability-related factors.
