There are three main salivary glands, which include the parotid, mandibular and sub-lingual glands. Saliva secretion is a reflex act stimulated by the presence of food in the mouth. The amount of mucus present in saliva is regulated by the dryness or moistness of the food consumed. Thereby in a dry diet, more saliva mucus is secreted while in a moist diet, only an amount to assist with swallowing is secreted. Saliva generally contains very low levels of amylase, the enzyme that hydrolyses starch to maltose. The contribution of digestive enzymes from saliva is minor but still noteworthy.