VEGETABLE FOOD 121 



182. Fermentation of grain in the alimentary canal. 



Owing to its large amount of starch and sugar, and to its comparatively 

 slow digestion, grain foods are liable to ferment. Fermentation will be 

 the least apt to occur with a mixture of about equal parts of animal and 

 vegetable food. 



183. Bread. Bread is the most common form of food 

 made from grain. Usually some means are employed to 

 make the bread porous and soft. Yeast is commonly 

 added. Its germs grow and change the sugar of the flour 

 to carbonic acid gas and alcohol. The gas, bubbling 

 through the wet and sticky flour, puffs it up and fills it 

 with small cavities, whose form the stiff and sticky gluten 

 preserves. Corn meal has but little gluten to make it 

 sticky, and so it will not preserve enough porous character 

 to form a loaf of bread. 



Instead of yeast, baking powder is often used to make 

 bread or biscuit light. The powder develops carbonic acid 

 gas, which bubbles through the dough. Nearly all baking 

 powders are minerals, and their use in large quantity is 

 undesirable. 



Bread made from wheat flour requires less energy in its 

 digestion than any other kind of vegetable food. Since 

 some starch must be eaten, bread, in combination with 

 milk, eggs, and meat, forms the best diet for everyday 

 use. Rye flour makes nearly as good bread as wheat flour. 



184. Other forms of grain food. Biscuit is bread with a 

 little fat added and baked in small lumps. 



Cake is a mixture of flour, eggs, fat, and sugar. A large amount of 

 fat or shortening tends to make it indigestible. 



Pancakes are made of flour, corn meal, or buckwheat flour. If they 

 are light and well cooked, they are of as much value as bread. 



Cracked wheat and other preparations of wheat are often boiled in 

 water, forming a mush or pudding. This has the composition and 

 digestibility of bread. 



