https://en.wikipedia.org/wiki/Saliva#Digestion https://en.wikipedia.org/wiki/Saliva#Digestion It's not clear that salivary digestion is categorically different

https://en.wikipedia.org/wiki/Saliva#Digestion https://en.wikipedia.org/wiki/Saliva#Digestion It's not clear that salivary digestion is categorically different from non-salivary digestion -- it works on compounds the rest of the GI tract also deals with -- but as a matter of degree, as a matter of the extent to which your food is digested, it certainly seems important. 30% is nothing to sneeze at.