﻿2 BULLETIN 17, U. S. DEPABTMENT OF AGEICULTUEE. 



fruit in the boxes. The temperature of the car followed the atmos- 

 pheric fluctuations to a slight degree, while the fruit was frequently 

 unaffected by a car temperature that rose or fell 5 degrees, provided 

 the increased or decreased temperature was not continuous. The 

 present investigation, which includes corresponding data for products 

 requiring lower temperatures than do citrus fruits, confirms and 

 amplifies this information. Powell fixed the fundamentals of the 

 transportation of refrigerated citrus fruits, which do not require a 

 temperature of less than 40° F., and if well handled survive at higher 

 temperatures. He also demonstrated that while the use of low 

 temperatures during transit might enable mechanically injured fruit 

 to reach the market in a salable condition, such fruit would not 

 stand the vicissitudes of marketing and would ultimately redound 

 to the disadvantage of the industries involved, as do all poor products 

 that reach the consumer. In this conclusion, also, the writers of the 

 present bulletin concur, and would lay even more emphasis than 

 does Powell on the bad results seen during the marketing of poultry 

 transported at fluctuating or excessively high temperatures. 



Decay in oranges, as well as in almost all other fruits, is definite, 

 and can be gauged with accuracy by inspection; not so with meats, 

 fish, dressed poultry, or eggs. Deterioration, the gradations of 

 which in these products are almost infinite, is so obscure that a 

 description of the appearance alone does not afford an accurate 

 method of fixing the point to which it has progressed. If an exact 

 statement of condition is desired, the laboratory must be depended 

 upon for the composition, since it is the variation between the com- 

 position at the time of killing and at the time of observation that 

 measures the changes occurring in the interim. In the course of 

 certain investigations conducted in the Food Research Laboratory 

 it has been found necessary to determine by chemical analysis the 

 effect of temperature upon the speed of decomposition of dressed 

 poultry. A summary of a large number of analyses of chicken flesh 

 from dressed birds kept at varying temperatures 1 showed in a strik- 

 ing fashion the relative rate of decomposition when all the factors 

 except the temperature were constant. The analyses include a 

 study of the distribution of protein and nonprotein nitrogen, the 

 latter increasing at the expense of the former as decomposition pro- 

 ceeds. 



Since the amount of nonprotein nitrogenous material is especially 

 indicative of deteriorative changes, an estimation of its quantity in a 

 flesh of known normal composition gives a ready means of measuring 

 the change that has occurred. A method 2 sufficiently rapid and accu- 



i Hearings before the Committee on Manufactures, United States Senate, Sixty-second Congress, May, 

 1911. 



2 An Application of the Folin Method to the Determination of Ammoniacal Nitrogen in Meat. J. Amer. 

 Chem. Soc, 1910, $2: 561. 



