130 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



are not apparently affected at all ; but if you increase the tem- 

 perature 100° or thereabouts they will suddenly be transformed 

 into dextrin. The change is an isomeric one, for dextrin is of 

 the same composition as starch. 



Now, the primary purpose in cooking the starch foods placed 

 on our tables should be to convert the starch so far as possible 

 into dextrin. Starch, as it is obtained in grain foods, cannot 

 be converted into dextrin without subjecting it for a long time 

 to heat, either directly or through convection in cooking in 

 water. The boiling of raw oatmeal for say thirty minutes will 

 not in all probability suffice to carry the starch far along in 

 the process of digestion, and this work must be completed after 

 the food is taken into the stomach if much nutritive value is to 

 be derived from it. On the other hand, if the cooking had 

 been carried on for a longer period less would have been left 

 for the stomach to do, which is the great object to be attained 

 in the cooking of these foods, — the relief of the digestive appa- 

 ratus. The processes essential to complete starch digestion 

 have been excellently set forth in a pamphlet presenting the 

 results of experiments prosecuted in the food laboratories of the 

 Battle Creek Sanitarium, in which it is shown that "water- 

 brash" and other dyspeptic symptoms so common among the 

 Scotch Highlanders is due to the excessive use of "Scotch brose," 

 which is simply raw oatmeal stirred up in hot water. The prev- 

 alence of indigestion in our own country, too, is due princi- 

 pally to the same cause, — the use of starchy or cereal foods in 

 an uncooked or imperfectly cooked condition. The pamphlet 

 goes on to say that : 



"The bread of the olden time consisted of thin cakes formed from a 

 mixture of flour and water, well kneaded and baked on a tin or stove 

 kept hot by a glowing fire. Bread prepared in this manner is ready 

 for prompt digestion and assimilation. 



"The transformation of starch into sugar — in other words, the diges- 

 tion of starch — takes place by stages. The starch is first converted 

 into 



"(a) Amylo-dextrine, or soluble starch. This is the form in which 

 it is found in well-boiled paste and in ordinary baker's bread, in so- 

 called ready-cooked breakfast cereals, and in mushes, gruels, vegeta- 

 ble soups, and similar preparations of starch. 



