The chemical process of digestion in the oral cavity is initiated by

Salivary amylase contributes to the chemical digestion in the mouth. It is secreted by the salivary glands. It initiates the breakdown of starch. Most of the dietary carbohydrates are starches, but only monosaccharides can be absorbed into the bloodstream. The function of salivary amylase is digestion of starch. It is broken down to smaller molecules such as the disaccharide maltose, the
trisaccharide maltotriose, and short-chain glucose polymers called α-dextrins.

Mastication of food by teeth is mechanical digestion.

Lysozyme present in the saliva exerts antimicrobial activity against microbes.

Saliva also contains lingual lipase. It is secreted by lingual glands in the tongue. This enzyme becomes activated in the acidic environment of the stomach. It breaks down dietary triglycerides (fats and oils) into fatty acids and diglycerides.