I do not believe there is a single word that exactly means the same as jutha, as that concept is particular to Hinduism. We would use the word as a loanword if necessary to be specific.
However, there are several general terms for left over food from plates, as opposed to leftover food which was never served (that being called leftovers).
- swill (specific to food waste given to pigs)
- food waste
As an aside, whilst this concept persists as a religious observance, there is the opposite end of the scale that should be more widely known, see the Filipino slum food pagpag.