Bonjour Ayanah,
Both adjectives have a meaning very similar -- pimentée --> hot, spicy, pour rendre plus piquant, plus savoureux,
-- piquante --> biting, sharp, tart (hot, spicy) sauce très relevée.
I believe that the adjective piquante is used to describe the taste of moutarde, vin and other foodstuffs whereas pimentée mainly dishes prepared for consumption.
https://www.cnrtl.fr/
This is my understanding -- perhaps a staff expert will be able to comment further.
Bonne continuation
Jim