Targeting use levels
The higher purity levels of rebaudoside-A, such as RA 80 or RA95 (80% or 95%, respectively) are essentially the same sweetness; RA50 is only a bit less sweet (sucrose equivalent). Formulating with more than 400ppm leads to bitterness so it’s diminishing returns. Next-gen stevia extracts may allow for somewhat high sweetness to facilitate deeper calorie reductions.
With beverages, for example, a 10% sucrose equivalent is a pretty important target. Because you can’t get there with Reb-A alone, blending is an important strategy. You can add a 2% sweetness equivalent – a zero-cal option like erythritol (derived from corn) works – so stevia starts at 2% and then you can get to 10% sucrose equivalent sweetness. So in addition to added sweetness, can also have positive effect on quality – quicker sweetness onset and more.
Managing sweet-sour balance
Blending acids balance taste. Citric acid and sugar have been blended for years. They’re equivalent and give a well-rounded taste. Blending lactic and malic acids is a good strategy to balance and round the taste experience with stevia.
Mouthfeel concerns is the primary textural attribute concern when you lose sugar. Losing sugar from foods also loses functionality like brown-ness. Mouthfeel provides a rounding effect. To help, use hydrocolloids like pectin or carageenan in dairy; erythritol and other polyols in other applications.
Flavors provide the finishing touches. Stevia taste modifiers and sweetness enhancers give a more sugar-like experience like masking off-notes and boosting sweetness intensity. In general, the more stevia you use requires more taste modification. Flavor suppliers design taste modifiers to work with specific flavor optimizers and offer them as a blended flavor solution. There’s no universal answer. The blends have to be tailored to work with the product you’re developing.