CHAJSTGES IN FRESH BEEF DUEING COLD STOEAGE. 97 



on account of the deficiency of our knowledge regarding the nutri- 

 tive vahies of the various cleavage products, it is by no means impos- 

 sible that the nutritive value of beef may be decreased by unduly 

 long periods of storage. 



FACTORS AFFECTING THE TIME THAT FRESH BEEF CAN BE 

 STORED AT TEMPERATURES ABOVE FREEZING. 



One of the objects in conducting the series of experiments reported 

 in this paper was to determine the length of time that fresh beef 

 could be held in cold storage at temperatures above freezing and re- 

 main in wholesome condition. The results of these experiments and 

 of observations upon the commercial handling of fresh beef in cold 

 storage have shown that the possible length of the storage period is 

 aiiected by a number of factors. On account of the importance that 

 has been attached to the time element in the cold storage of fresh 

 beef, and in the storage of other fresh meats as well, it has seemed 

 desirable to present a brief discussion of this phase of the subject. 



The principal factors which affect the length of time that fresh 

 beef can be held in cold, storage at temperatures above freezing are 

 as follows: (1) The character of the beef; (2) the temperature of 

 storage; (3) the humidity of the cold-storage room. 



Character of heef. — The condition of beef, as regards its degree of 

 fatness or finish, is an important factor in determining the length of 

 time that the beef will keep in cold storage. Thin, soft carcasses of 

 old cows or grass-fed cattle are apt to undergo comparatively rapid 

 deterioration in cold storage. The large exposed surface of musculaj* 

 tissue and the soft character of the meat offer favorable conditions 

 for the development of molds and bacteria. It is generally recog- 

 nized l)y packing-house men that beef of this character must be 

 handled with dispatch. On the other hand, highly finished carcasses 

 from prime, grain-fed cattle will keep in cold storage for a much 

 longer time. The flesh of such carcasses, which is firm in character, 

 is usually covered in large part with a surface deposit of fatty tissue, 

 which becomes firm on cooling and through loss of moisture, and thus 

 aids in protecting the muscular tissue against bacterial invasion. 



Temperature of storage. — In commercial practice chilled beef is 

 ordinarily held in cold storage at a temperature between 34° and 

 30'^ F., altljough occasionally temperatures as low as 30° F. or as 

 high as 40° F. may be employed. A temperature of 40° F. is regarded 

 as about the upper limit of safety in the handling of fresh beef in 

 cold storage, while it will freeze at a temperature slightly under 

 31° F. Other conditions being the same it is clearly apparent that 

 chilled beef will keep longest at 31° F. 



Iluraidity of eold-atorage rooms. — The importance of dry coolers 

 for the proper handling of chilled beef is genei-ally recognized. A.s 

 a rule, however, no special means are used to regulate the humidity 

 of beef or other fresh-m<;at coolers, the desired condition usually be- 

 ing obtained by the proper construction and management of the 

 cooler.s. Various factors nuiy a fleet the humidity of coolers, but they 

 will not be discussed. 



There seems to be pnictically no information available regarding 

 the humidity of packing-house cooh'rs in this counti-y. In order to 

 sefure accurate information on this subject, humidity readings were 

 r^',n/i;^ r_i;ull. 4.",:j— 17 7 



