“Sweetness is measured in how quick and how long sweet lasts in your mouth," explains Laura Ennis, senior beverage innovation technologist, David Michael & Co., Philadelphia. This can be measured by a temporal sweetness profile. “Different sweeteners are rated on their intensity over time, and these results can be plotted onto a graph. For example, crystalline fructose peaks very early and fades rather quickly, whereas sucrose peaks later and lasts longer, hence the reason that most chewing gums are accentuated with artificial sweeteners to keep the sweet profile lasting longer. Non-nutritive sweeteners tend to take the longest to peak and, therefore, lack this upfront sweetness."
Perception of sweetness occurs when a sweet molecule comes in contact with a sweet receptor in the taste bud. “Protein conversions lead to depolarization of the cell, which then leads to a buildup of the ions within the cell and causes the neurons to perceive sweetness," says Richard Davidson, vice president, Hagelin Flavor Technologies, Inc., Branchburg, NJ.
When the receptor is saturated, more sweetness can’t be detected. “If you drink a soda and then eat a piece of candy, depending on how much sugar is in the candy, you can’t taste the sweetness of the candy because you’ve already peaked the receptor. It can’t detect any more sweetness. You get to a point of diminishing returns."
Sweetness can seem enhanced by mouthfeel. “Perceiving more fullness in your mouth aids in sweetness perception," says Ennis. “Fats and bases that coat the mouth can detract from sweetness."
In the search to reduce sugar consumption and to optimize sweeteners, the industry is trying to come up with a silver bullet that will trick the cell into thinking a molecule is more sweet than it actually is.
“You can go the old-fashioned way and use a molecule that is sweet. Sometimes we use vanillin, ethyl vanillin or helioptropine," Davidson says. "Those are components that will make you perceive more sweetness, but unfortunately they also carry flavor characteristics. Vanillin is going to taste vanilla-like. Heliotropine is going to be more of a cotton candy type flavor. Caramel furanones add sweetness, but again, they are characterizing."
Flavor companies are developing molecules built to get the receptor to depolarize more rapidly to give a stronger sweetness perception without adding a flavor note. “You want to act on the chemistry on the cell, not to induce the flavor response," Davidson says. “That’s been the trick."
