In John there's no Eucharist ritual, but there's a scene where Jesus dips bread and feeds it to Judas.
This is explained away as a sign of who will betray Jesus.
In Mark, this again happens, but now it doesn't mention that it's bread, and immediately precedes a Eucharist ritual.
In Matthew, which was copying from Mark, it makes it a dipped 'hand' instead, further distancing any association with bread.
On a completely unrelated note, anyone ever wonder why in the Eucharist ritual, if the bread is supposed to be the body of 'Christ,' which is the Greek word literally meaning 'anointed,' the bread isn't being anointed or dipped in anything before being consumed?
In the Roman Catholic ceremony, the priest drops a piece of the Eucharist into the wine and then drinks that together. That's the ceremonial 'dipping' part. It's easy to miss but I remember always wondering how that tastes, because those Jesus breads dissolve when you breathe on them.
(I don't know how strict Roman Catholic churches are, but I imagine they try to keep that shit pretty standard)