"We do need that too." Senku said agreeably. "But the zest is the orange part on the outside. Normally you wouldn't eat the outside, and you can't really eat all of it."

He washed an orange first, before cutting it half and putting the flat side down on the cutting board, then he took the knife to try and slice thin pieces off. "You want just the orange part. There's tools that do this so much easier but I'm working with what I've got here. What you can't really eat is the white part inside the orange part so...." He held it up for inpsection before cutting it into tiny strips. "It's supposed to make things taste more like orange than they would with just the juice."