The digestion of starch (carbohydrate) is initiated in mouth due to the action of starch digesting enzyme ptyalin or salivary amylase present in saliva secreted by salivary glands. Enzymatic hydrolysis helps in the partial breakdown of starch (polysaccharide) into maltose and isomaltose (disaccharides) and small dextrins called 'limit' dextrins. Nearly 30% of the starch is hydrolysed in the oral cavity because of the shorter time the food is retained here