As nouns the difference between sweetener and thaumatin
is that sweetener is a food additive that sweetens, especially an artificial substitute for sugar while thaumatin is a virtually calorie-free protein sweetener and flavour modifier.
sweetener
English
Noun
(
wikipedia sweetener)
(
en noun)
a food additive that sweetens, especially an artificial substitute for sugar
(informal) something added as an inducement or incentive; a kickback
thaumatin
English
Noun
A virtually calorie-free protein sweetener and flavour modifier.