These Treasures affect most special abilities that are limited to certain types of enemies. Each Fruit Treasure is limited to one type and with all seven activated, the only anti-trait abilities that will not get the bonus are those targeting Traitless, Aku or Relic enemies.
At 100% on all Fruit Treasures:
The Strong Against effect goes from 1.5x damage dealt to 1.8x damage dealt, and 0.5x damage received to 0.4x damage received.
The Massive Damage effect goes from 3x damage dealt to 4x damage dealt.
The Insane Damage effect goes from 5x damage dealt to 6x damage dealt.
The Resistant effect goes from 1/4 damage received to 1/5 damage received.
The Insanely Tough effect goes from 1/6 damage received to 1/7 damage received.
The Freeze, Slow, Weaken, Curse and Dodge Attack effects are increased in duration by 20%.
Finally, the Knockback effect's distance is increased by 30%.
Like the abilities they affect, they do not stack on multi-traited enemies. There still appears to be some uncertainty about what exactly each Treasure set's effect is alone.
If the Fruit Treasures are not at an equal amount when a cat with multiple targeted traits is used against an enemy with more than one of its targets (e.g., Baby Gao vs. Bears Be Back while Blood Fruit is at 100% and other Fruit Treasures are at 200%), the Fruit Treasure with the highest % will take priority.
The Fruit Treasures originally only improved the Weaken effect's duration by 10% and the Knockback effect's distance by 20%. This was changed at an unknown date.
Even though the Titanium Fruit does boost Strong Against, Massive Damage and Insane Damage, they will not affect Metal enemies unless combined with a Critical Hit.