Food scientists have cut the sweetener stevia’s bitter aftertaste by physical—rather than chemical—means.
“The food industry constantly evaluates and uses several alternate high-intensity sweeteners to duplicate the taste of sugar, usually with no calories,” says Samriddh Mudgal of Cornell University, lead author of the study in the journal Food Chemistry.
“Growing demand for natural ingredients have led to the rising popularity of steviol glycosides, which are natural sweeteners extracted from stevia leaves. They’ve been in use for centuries in South America. Since these steviol glycosides have a negligible effect on blood glucose, it is an attractive, natural sweetener for people on carbohydrate-controlled diets.”
The findings could encourage the beverage industry, as well as makers of packaged dressings, cream sauces, powdered soups, and dairy products, to use more stevia.
While previous studies have focused on masking taste receptors, Mudgal and his colleagues took a different approach. One of stevia’s components is rebaudioside A—the glycoside molecule that provides its sugary taste but yields the speck of bitterness that limits the sweetener’s commercial possibilities.
When tasted now, Reb A activates two bitter receptors—hTAS2R4 and hTAS2R14—on the human tongue.
The researchers modified Reb A by applying “hydrophobic effects” to the bovine serum albumin protein, which creates a stable Reb A-protein complex, and it essentially dissipates the Reb A molecular components. This protein solution disengages stevia’s bitter components, as the human tongue’s bitter receptors hTAS2R4 and hTAS2R14 are less likely to recognize the modified Reb A-protein complex.
The researchers tested the modified protein’s sturdiness in orange juice and found the sweet binding remained intact.
“It’s a chemical-free, economical, and purely physical interaction-based approach to control Reb A’s interaction with taste receptors, which will bolster its taste profile,” says Mudgal.
Source: Cornell University