46 BULLETIN 908, U. S. DEPARTMENT OF AGRICULTURE. 



During the first hour (Table 18) nearly 1 pound of material, or 

 0.7 per cent of the total weight of fish and salt at the beginning of 

 the experiment, was lost. The greatest loss occurred at the end 

 of the 4-hour period. After being "dry salted" for 20 hours, the 

 total loss of material, water, salt, and protein substances amounted 

 to 28 pounds, or 19.05 per cent of the weight of the fish and salt at 

 the beginning of the experiment. This is 3.12 per cent less than that 

 found in Experiment 1. The volume of the brine collected during 

 the 20 hours amounted to 10,860 cc, which, as a saturated salt solu- 

 tion, would dissolve 3,910 grams, or 8.6 pounds of salt. This leaves 

 19.4 pounds as the actual loss of water and nitrogenous material re- 

 moved from the fish during the 20 hours in salt, and is 15.65 per cent 

 of the total weight of fish employed at the beginning of the experi- 

 ment. This is 2.75 per cent less than that abstracted in Experiment 

 1 for the same period of time, showing that the fatter fish lose less 

 extractive material while in salt. 



Practically one-quarter and one-fifth, respectively, of the original 

 weight of fish and salt was lost in 20 hours, the smaller loss occurring 

 in the case of the fatter fish. An appreciable amount of nitroge- 

 nous substances was extracted from the fish during the time they 

 remained in salt, although, as shown by the figures in Table 15, not 

 as much as would have been removed had the fish remained in 

 pickle for corresponding periods. This is due to the fact that a 

 number of protein substances are rendered insoluble by salt and 

 very strong salt solutions. As the solution grows weaker, or if very 

 weak pickle is used, a larger proportion of these protein substances 

 are dissolved. These substances give fresh fish the characteristics 

 which distinguish them from salt fish. The maximum quantity 

 of the nitrogenous material was extracted at the end of the first 

 4 and 6 hours, a marked increase being shown at these periods 

 over the 2-hour period when the fish were salted at the rate of 

 one sack per hogshead. 



The results of these experiments indicate that 2 hours or less is the 

 proper period of time for pickling or dry salting the fish, when the loss 

 of the minimum quantity of extractive material is considered. The 

 time allowed in the older method when the fish were pickled in the 

 pickling sheds, usually 2 hours, permits the conservation of the 

 maximum quantity of those extractive substances which are char- 

 acteristic of fresh fish. 



Effect of Various Steps in Canning Process on Salt Content of Sardines. 



A number of analyses were made to determine the variation of the 

 salt content of the fish at different stages of the canning process 

 under actual commercial practice. The results are given in Table 19. 



