thaumatin
Concise Oxford English Dictionary © 2008 Oxford University Press:
thaumatin /ˈθɔːmətɪn/
▶noun a sweet-tasting protein isolated from a West African fruit, used as a sweetener in food.
– origin 1970s: thaumat- from mod. L. Thaumatococcus daniellii (name of the plant from which the fruit is obtained) + -in1.
'thaumatin' also found in these Oxford entries:

