Some definition of staling:            Broadly speaking, bread staling refers to all changes that occur in bread after baking. Changes occur in both the crumb and the crust of the bread. The increase in crumb firmness has probably been used to the largest extent by investigators following bread staling. Other changes, however. Such as loss of flavor, decrease in water absorption capacity, amount of soluble starch and enzyme susceptibility of starch, increase in starch crystalline and opacity. Firmness is an important sensory attribute of bread. Bice and Greddes (1949) concluded that firmness and crumbliness are related closely to organoleeptic assessment of staleness . Literature on the staling of bread and on the methods for the  measurements of the extent of the staling are scare.