THE SALTING OF FISH. 43 



method is, therefore, more economical in regard to salt, as well as to 

 labor. 



SUMMARY. 



1. The formation of amino-acid nitrogen was followed in the brine 

 during the salting of fish by two methods — salting by use of dry 

 salts and salting by use of brine. 



2. The total amount of amino-acid nitrogen formed during salt- 

 ing was calculated. 



3. More amino acid was formed by the brine method of salting. 



4. The estimation of the amino-acid nitrogen content of fish and 

 brine was suggested as a means of detecting and also forecasting 

 spoilage, 



5. Tlie rate of penetration of salt into the squeteagu© when salted 

 with dry salt and when salted with brine was detennined. Salt 

 applied dry goes into the fish more rapidly. 



6. Samples of the fish salted by the two methods under considera- 

 tion were cooked. It was found that all of the fish salted with dry 

 salt at 80° F. were edible. Those salted with brine were unfit for 

 consumption. 



7. The dry-salt method was found to be more economical both of 

 labor and salt. 



These rasults show that the dry-salt method of salting fish, as 

 practiced conmiercially, is much more efficient in preserving fish than 

 the brine method. The dry-salt method is also the more economical 

 of the two. 



III. INFLUENCE OF METHOD OF CLEANING FISH FOR SALTING. 



INTRODUCTION. 



IMPORTANCE OF METl'HOD OF CLEANING. 



It has always been known that the method of cleaning a fish pre- 

 paratory for salting has an important influence on the quality of 

 the product. From the first the writer noted that the salt penetrated 

 more rapidly through the cut flesh of fish than through a surface 

 covered with skin. This was first noticed while following the pene- 

 tration into the fish of salt containing calcium chloride. The cal- 

 cium chloride produced a marked whitening of the tissue. This was 

 observed to proceed more rapidly on the cut side of the fish than on 

 the side covered with skin. 



The common practice in rating the quality of a salted herring or 

 alewife is to break the fish open so that the backbone is exposed. 

 The odor of the dark red or brown spots is then observed. The 

 experienced fish Salter knows that these spots are the first parts of the 

 fish to spoil. They are caused by the coagulation and partial de- 

 composition of the blood. Most fish salters seem to realize that the 

 blood is the most unstable substance contained in fish, for they rate 

 the efficiency of difi^erent procedures in fish salting by the amount 

 of blood that the processes " draw out." They are welt aware of the 

 fact that round fish can not be salted at as high a temperature as cut 

 fish. Numerous fishermen have advised the writer that very little 

 35286°— 21 16 



