Misa and an apple.
The apple is bitter.
If you leave an apple in the refrigerator for too long, it will dry out and become powdery, but it will still remember being an apple, hanging in the tree and soaking in the warmth of summer.
Ryuk's apple only remembers death and an eternity lying in the powdery bodies of shinigamis who had forgotten they weren't alive and become engaged with the living, who would never know or care for them in return.
Misa spat out the bite she took immediately, and though she rinses out her mouth again and again, the bitter taste remains.