USES OF CEREALS 559 



cereals ground which must be prepared for the table be- 

 fore serving; (2) the prepared breakfast foods, which 

 have been steamed or otherwise cooked and then rolled or 

 ground ; and *(3) malted foods, in which a portion of the 

 starch has been changed chemically by the action of malt. 



609. Unprepared foods. Twenty-five years ago prac- 

 tically the only cereal foods on our market were wheat 

 flour, corn meal, and hominy, though oatmeal had been 

 introduced but was not yet widely used. Barley, rye, 

 and rice were used in a small way. Oatmeal is yet prob- 

 ably the most important unprepared breakfast food. It 

 also contains the largest quantities of the important 

 nutrients, with a fairly low proportion of crude fiber. 

 Snyder concluded from experiments that the difficulty 

 in digesting imperfectly cooked oatmeal is due to the 

 large amounts of glutinous material which surround 

 the starch grains and prevent their disintegration. When 

 thoroughly cooked, the protecting action of this mucilagi- 

 nous material is overcome, and the compound starch 

 grains are sufficiently disintegrated to allow the digestive 

 juices to act. Heat also has the direct effect of rupturing 

 hard cell walls. Cereals differ very much in the amount of 

 cooking required to make them as digestible as possible. 

 It may always be remembered that over-cooking is unusual 

 and harmless, while under-cooking is common and undesir- 

 able. Some cereals absorb much more water than others 

 before they are sufficiently cooked. Oatmeal increases 

 its water content from 70 per cent to 84 per cent in cook- 

 ing. Puffed rice and puffed wheat are kernels expanded 

 by heating them under pressure at a high temperature, 

 and then suddenly releasing the pressure. 



Barley water is an old-fashioned beverage made by 

 boiling barley in water and straining the clear liquid 



