INVESTIGATIONS IN HUMAN NUTRITION. 375 



the insertion of thermometers into the interior parts of the meat is 

 shown to be the only accurate method of controlling the extent of 

 cooking, because the appearance and temperature of the outside are 

 not reliable evidence, even to the experienced observer, of the tem- 

 perature within. The data reported show that it is possible to 

 obtain uniform results in the cooking of meats. As a whole, the 

 investigations summarized are of great interest and value to the 

 student as well as to the housekeeper. 



Experiments were also made by Grindley and his associates as part 

 of the extended investigations of the comparative composition and 

 quality of fresh and cold-storage beef and fresh and cold-storage 

 chicken, both drawn and undrawn. This work, which is extended 

 and valuable, is referred to elsewhere. (See p. 369.) 



Changes brought about by the action of heat on individual muscle 

 fibers are of importance in discussing cooking problems, as it is the 

 sum of these changes which in a large measure is accountable for the 

 dilYerences in texture between raw and cooked meat. A paper of 

 interest in connection with studies of cooking meat was published by 

 Meigs" under the title "Concerning the Supposed Connection Between 

 Protein Coagulation and the Heat Shortening of Animal Tissues." 



Many cooking tests, which in some cases include records of cost and 

 quantities, have been made by Miss Caroline Hunt at the Oflice of 

 Experiment Stations in connection with studies of the economical 

 use of meat in the home. The data obtained have been reported as 

 part of an extended discussion of the problem recently published by 

 this Oflice as a Farmers' Bulletin.'' 



Various investigators have studied changes produced in starches 

 during cooking, and a report on this subject b}^ Prof. Edna D. Day*= 

 has been published. Careful tests were made of the different forms 

 of amy lose and other constituents of various starch grains, and the 

 amount of heat required to reduce them to a paste; their digestibility 

 in different conditions was also tested artificially. The following 

 practical conclusion is quoted here: 



Increa.«inj^ the proportion of (liasta.«e to starcli in artificial digestion experiments 

 markedly hastens the digestion of both blue and red amylose. It would appear, 

 therefore, that eating starchy foods slowly, which would of course increase the 

 proportion of saliva and ptyalin to a given quantity of starch, would be of more value 

 from the standpoint of fligestion than would any cooking of starch beyond the stage 

 of paste formation. 



A summary of much work with starches Is found in a bulletin by 

 Margaret J. Mitchell, entitled "Course in Cereal Foods and Their 

 Preparation,"*^ intenilod for class-room use, especially in the mova- 



1 Amer. Jour. Physiol., 24 (1909;^, No. 1, p. 178. 

 b U. S. Dept. Agr., Farmers' 15ul. 391. 

 c U. S. Dept. Agr., Office Expt. Stas. Bui. 202. 

 d U. S. Dept. Agr., Office Expt. Stas. Bui. 200. 



