84 COOKING AND ITS EFFECT ON FOOD 



tissue is made up of bundles of muscular fibers, which appear 

 single to the unaided eye, but which are in reality composed 

 of hundreds of thin, delicate muscle tubes held together by con- 

 nective tissue. The delicate muscle tubes are composed of a 

 substance known as fibrin, while the connective tissue which 

 binds them together is composed of a totally different substance 

 known as collagen or gelatin. 



Meat juices are rich in albumin and in extractives or sub- 

 stances which give flavor to the meat. The substances which 

 give flavor to meat are called extractives because they are easily 

 removed or extracted from it. For instance, if meat is soaked 

 in cold water, the flavoring substances pass into the water 

 and the meat becomes tasteless. 



The effect of heat on the constituents of meat. One 

 object of cooking is to soften and to loosen up the con- 

 nective tissue and to make it easier for the digestive juices to 

 act upon both connective tissue and muscle fibers. Gelatin, 

 the main constituent of connective tissue, softens and swells 

 under the influence of heat, and if the heat is continued long 

 enough, it slowly dissolves. Meat should not be cooked until 

 the gelatin of the connective tissue dissolves and the muscle 

 fibers fall to pieces, but it should be cooked until the raw gelatin 

 has been softened and converted into a substance readily soluble 

 in the digestive juices of the body. 



Gelatin is frequently removed from meat and used as a 

 basis of desserts. It is obtained by cooking meat in hot 

 water until the gelatin in it softens and dissolves in the water. 

 The water is then evaporated away and the soft dry mass 

 which is left is packed in boxes and sold as prepared gelatin. 



Albumin which is present in the meat juices is affected by 

 heat in exactly the same way that albumen in eggs is affected. 

 Slow cooking with moderate heat softens and loosens the con- 

 nective tissue, makes the muscle tubes tender and less compact, 



