1921.] Wright.—Chemical Technology of Meat Industry. 79 
product is an art. Processing, more than any other single operation, should 
be based upon an exact knowledge of the requirements of each article. 
Raw material of the finest character may be supplied, but by improper 
processing may become of inferior quality ; while low-grade stock or that 
which is partially decomposed may be sterilized, but the most careful 
manipulation will not convert it to a first-class article of food. Intelligent 
processing must depend not only upon a knowledge of the types of 
organisms found upon the different foods and upon the character of the 
product with reference to the conduction of heat, but also upon the 
changes effected by various degrees of heat. 
From a commercial point of view the effect of the processing upon a 
product 'must be considered of equal importance to that of sterilization, 
and vice versa. 
It will thus be seen that any detailed account which may afford exact 
data regarding the processing of a given product is of little use unless 
supplemented by the modifications and reservations which are necessary 
if details were given. For this reason it is possible to note at this stage 
only the general principles involved. 
The temperature and time of heating depend chiefly upon the size of 
the can, but also to some extent upon other conditions. Probably the 
most usual temperatures for processing are from 225° to 250° F. As meats 
are but poor conductors of heat, it is important to be sure that the 
temperature in the centre of each can is maintained adequately. 
Usually the cans are first processed in a bath of brine made with calcium 
chloride in solution, and possessing a high boiling-point ; it is thus possible 
to “boil off” at a temperature well above 212° F. At the close of this 
process the vents in the cap of the can are closed with a drop of solder. 
The cans are then removed to large iron retorts, which are heated by 
superheated steam, and the processing finished. 
The cans are then subjected to a cold spray until the contents are 
chilled, when the ends of the can should be slightly concave, and should 
remain so until the can is opened for use. 
In some plants the cans are placed with the open vent in a vacuum 
apparatus, the air is extracted, and the vent closed in vacuo. By this 
means it is possible to eliminate the preliminary “ boiling off ” process 
and to conduct the processing in one operation. 
It should be borne in mind, however, that the sealing in vacuo does 
not in any way obviate the necessity for thoroughly processing and sterilizing 
the can by heat, after sealing the vent. 
The meats used in the preparation of corned mutton and beef are the same 
as those used for the boiled and roast meats. The pieces, cut and trimmed 
as described, are cured in a brine of salt and saltpetre, with or without the 
addition of sugar. The period of curing varies in accordance with the 
ideas of the individual manufacturer, but is usually about twenty days. 
The corned meat must be boiled for a longer time than the fresh, owing 
to the large amount of salt that is left from the curing process. 
The canning of the corned meat is similar to that of the boiled and 
roast. 
On account of the thorough cooking which corned meat receives before 
canning, as well as the sterilization of the curing process itself, it may be 
processed at a lower temperature or in less time than roast or boiled 
meats. 
Tongues are cured in a manner similar to that adopted for corned 
meats, except that in some cases more sugar is added to the brine. After 
removal from the curing-brine the tongues are cooked by boiling, trimmed, 
