の芯

core; cob; tube

→ の
phrase Rare #35,237
core; cob; tube Used after a noun to refer to its central or inner part, such as an apple core, a corn cob, or a toilet-paper tube.
JA: バナナの芯は食べません。
EN: I don't eat the core of a banana.

子猫一匹トイレットペーパーの芯で遊んでるよ

One of the kittens is playing with a toilet paper roll.

トムりんごの芯ゴミ箱捨てた

Tom threw the apple core in the trash.

私は林檎の芯食べません

I don't eat apple cores.

トウモロコシの芯

corn cob

— 続・夕陽のガンマン (1966)

林檎の芯は食べないよ

I don't eat apple cores.