It means proteins derived from 'new' sources. Animal proteins are inefficient to make (as the animal has to make them from vegetable matter first-cows eating grass!). Novel proteins are either isolated directly from plants, or obtained by microbiological methods from fungi or yeasts.
Novel protein can also mean a protein that you have never been exposed to before-in vet science, some animals can be allergic to certain proteins and are tried on different types to see if it suits them better.
Novel protein can also mean a protein that you have never been exposed to before-in vet science, some animals can be allergic to certain proteins and are tried on different types to see if it suits them better.