( ( ( The digestion ) ( of starch ) ) ( ( ( begins ( in ( the mouth ) ) ) ( through ( ( the action ) ( of ( salivary amylase ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN digestion)) (PP (IN of) (NP (NN starch)))) (VP (VBZ begins) (PP (IN in) (NP (DT the) (NN mouth))) (PP (IN through) (NP (NP (DT the) (NN action)) (PP (IN of) (NP (JJ salivary) (NN amylase)))))) (. .)))
The digestion of starch begins in the mouth through the action of salivary amylase.
(ROOT (S (NP (NNP Digestion)) (VP (VBZ begins) (PP (IN in) (NP (DT the) (NN mouth)))) (. .)))