The ash content is a measure of the total amount of minerals present within a food, whereas the mineral content is a measure of the amount of specific inorganic components present within a food, such as Ca, Na, K and Cl. Thus, ash content refers to the total mineral residue left after incineration of organic matter. It has no nutritional significance per se, but the value for ash is a useful check in summing up the proximate composition of food and a measure of its mineral content. It is expressed as g ash per 100 g sample. Determination of the ash and mineral content of foods is important for a number of reasons: