Wright, Bbvis, and Nelson. — Chemistry of Flesh Foods. 479 



Art, LII. • — ■ The Chemistry of Flesh Foods. — (5) The Nitrogenous 



Constituents of Meat-extracts. 



By A. M. Wright, A.I.C., F.C.S. ; (Miss) J. F. Bevis, B.Sc. ; and the late 



P. S. Nelson, M.Sc* 



[Head before the Philosophical Institute of Canterbury, 1st December, 1920 ; received by 

 Editor, 31st December, 1920 ; issued separately, 12th August, 1921.] 



This paper is a continuation of the investigations of flesh foods which 

 are being carried out in the laboratory of the New Zealand Refrigerating 

 Company (Limited) (1. 2), and covers a number of investigations dealing 

 with the composition of meat-extracts. These have been carried out since 

 the publication of a former contribution on the subject (3). 



Manufacture. 



In general, commercial meat-extracts are manufactured from finely 

 chopped lean meat (the muscular tissues of flesh), which is placed in 

 tanks containing cold water ; steam is admitted, and the material is heated 

 for about half an hour. The liquor obtained from meat which is parboiled 

 in the process of preparing certain canned meats is also utilized. The 

 liquors while hot are pumped into a large tank and there settled in order 

 to separate out in part the particles of meat-fibre which are present ; the 

 supernatant liquor is then filtered to remove any solids in suspension, the 

 fat present is skimmed off, and the clear liquid is concentrated in steam- 

 heated pans, either under vacuum or at ordinary atmospheric pressure, 

 the partially concentrated liquor being finally transferred to a finishing- 

 pan and heated until the water content approximates 20 per cent, and 

 the material is of a syrupy consistency. 



It is obvious, therefore, that meat-extract can contain only a small 

 part of the nutriment of meat, for there is practically no albumen or fat 

 present, and very little gelatine ; the extract consists of salts and extractives 

 of the meat. It is the nitrogenous extractives which give meat-extracts 

 their chief value, and these have been classed under the sornewhat loose 

 term of "meat-bases" (3). The meat-bases are products of the breaking- 

 down of proteins in the vital processes of the body, and are excreted for 

 the most part unchanged, and have little or no value as builders of tissue ; 

 they cannot be strictly regarded as foods, but possess certain stimulating 

 properties, and apparently furnish relief to fatigued muscle and are powerful 

 excitants of gastric secretion. 



The results of an examination and identification of the various nitro- 

 genous constituents of a number of meat-extracts have already been 

 published by one of us (A. M. W.) (3), so that it is unnecessary to record 

 the data covering the work then published. 



* The late P. S. Nelson was killed in action during June, 1917. 



