Mastication, << `mas` tuh KAY shuhn, >> is the first process in the digestion of food. It involves chewing or breaking the food into small pieces by grinding with the teeth. Mastication mixes the food with saliva, which reacts chemically with the food and also gives it a pasty texture. Saliva contains enzymes, including ptyalin, or amylase, which digests cooked starches into sugars; and lipase, which digests fats. It also contains a slimy mucus that lubricates the food so it can be swallowed. In addition, saliva contains bicarbonate of soda and other salts that buffer the acids or alkalis found in some foods and drinks. Poor mastication causes overworking of digestive organs and indigestion. See also Digestive system ; Indigestion .
