MAINE SARDINE INDUSTRY. 71 
Table 30 gives the results of the determinations of ammoniacal 
nitrogen in sardines stored for various periods of time. 
TABLE 30.—Ammoniacal nitrogen content of sardines stored for various periods. 
Ammoniacal _ni- 
trogen per 100 
grams. 
Condition of fish. Period held. , 
Titra- 
Nessler. aya, 
Mg. Mg. 
IPOS es Aiea | ern erence 107.8 147.6 
DO ee ee 24 hours....... 121.7 189.6 
Tn pickle: 
1 (0) | Per ee WemMonthsSseeseeleeeee anes 203.1 
NOUR soe eee (oS eS ARAB ee ceraerenes 206.1 
AHOUTS) oa eee GO Be ensta  it ees 204.5 
2 NOUR ee ee ase LOWMOntHSS ee Pees ee 271. 
1hHOUTE sates lee CLOW eee es ie ae el ate 239.4 
| ISH OUTS ee Alene CB (Oya nr SPENT er ay CU 223.0 
From the nature of the material, coupled with the well-known fact 
that amines are formed in the decomposition of fish, fish brine being 
a source of trimethylamine, amines were naturally looked upon as 
responsible for the discrepancy between the values obtained by the 
two methods of analysis, and possibly were partly responsible for the 
increase in the ammoniacal nitrogen which occurs on standing. 
Evidently a change occurs in canned sardines on standing, sub- 
stances having an alkaline reaction (amines), determined as ammonia 
by the titration method, being liberated. Unfortunately, the Nessler 
method for determining ammonia is not reliable in the presence of 
amines. ‘The difference in the values obtained by the methods em- 
ployed for ammonia, while giving some indication of the amount of 
amines present, is not even sufficiently accurate to warrant regarding 
it as an approximate measure of the amine content. 
The interesting fact that older packs of sardines contain larger 
amounts of ammoniacal material than those which have stood for 
only a short time was definitely proved by analyzing samples of 
commercially packed sardines which had stood for 2, 4, and 6 
years in a cellar where the temperature was practically uniform 
and never reached the freezing point. In these analyses determina- 
tion of the total volatile nitrogen and ‘“‘ammonia’”’ by the Nessler 
method, as well as the separation of ammonia and amines in the total 
volatile material, were made. 
On opening the cans the two brands which had been packed for 2 
years were found to be in very good condition. The fish were 
slightly colored by what appeared to be iron from the lid of the 
can, which was badly detinned. The cans in the 4-year-old lot 
looked worse than any of the other samples. A large amount of a 
white, soft material, probably stearin from the oil, was spread over 
