Only Google books even comes close :-)
I have yet to gain sufficient experience in indexing but coming from an IT background, I would expect it to be easier to code. For the indexer it should make no change to their current method unless they were indexing a reference book. For a reference book it would add an entry per headword but that would be a very simple entry.
However, it is my limited experience in searches returning erroneous results on ingredients and my difficulty in finding appropriate ingredients for manually added online recipes that made me create the suggestion