94 



of such materia] is an important matter, and studies with special ref- 

 erence to the ])odies existing in fats are needed. From the investiga- 

 tions made in this laboratory and other available data, it seems fair to 

 conclude that the flavors developed in the cooking of meat ])y the 

 ordinar}' household methods are due very largely to the oxidation of 

 extractive bodies in the meat juice and to the oxidation of fat. 



BEEF BONES COOKED AS IN SOUP MAKING. 



Series XV. — Experiments Nos. 127-130. 



The four experiments included in this series were made with bones 

 rather than meat in order to investigate the losses and changes which 

 they sustain when cooked in hot water at different temperatures, as in 

 ordinary household soup making. 



In general the same methods were followed as in the tests in which 

 meat was boiled, save that no attempt has as yet been made to analj^ze 

 the bones before and after cooking. So far the amount and nature 

 of the substances which bones yield when cooked in hot water have 

 been determined entirely from the chemical composition of the 

 resulting broths. 



For the first two experiments (Nos. 127 and 128) beef rib bones, 

 scraped to remove as much of the meat as possible, chopped into pieces 

 from 0.6 to 1 inch in length, and thoroughly mixed, were divided into 

 two portions, each weighing 1,000 grams. The first portion, for 

 experiment No. 127, was placed in 2,000 cubic centimeters of vigorously 

 boiling water and cooked for five hours. The resulting soup or broth 

 was filtered and analyzed according to the methods described in an 

 earlier section. 



The second portion of bones (experiment No. 128) was cooked in 

 2,000 cubic centimeters of distilled water for ten minutes at the tem- 

 perature of boiling water and for five hours at a considerably lower 

 temperature, i. e., 84° or 85° C. The soup or broth was analyzed in 

 the same way as the meat broths. 



For the last two experiments of this series (Nos. 129 and 130) beef 

 shank bones were scraped to remove as much of the meat as possible, 

 sawed into pieces about 1.6 to 2 inches long, thoroughly mixed 

 and divided into two portions weighing 1,000 grams each. The first 

 portion (experiment No. 129) was placed in 2,000 cubic centimeters of 

 vigorously boiling water and cooked at this temperature for five hours. 

 The resulting broth was subjected to the usual treatment and analysis. 



The second portion of shank bones (experiment No. 130) was cooked 

 in 2,000 cubic centimeters of distilled water for ten minutes at the 

 temperature of boiling water and for five hours at 84° to 85° C 



The results of these four experiments are given together in Tables 

 95 and 96. 



