Absolutely not sure but isn't starch just a long chain of sugars that we can break apart?
Might not get it down to a monomer but certainly breaks it apart for the enzymes to have more ends to attack.
I worked on a process to reduce a vatful of long-chain polysaccharides to dextrose. The resulting dried powder was shipped as 'coffee creamer'. But not sure how efficient the process would be on starch - we started with much shorter chains (sucrose etc but some starch).
I don't believe that's possible either, but processing can make a lot more surface area available on which enzymes can then act.