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



the fish. The fish in the cans of the 6-year-old lot were covered 

 with the same soft, white material. These cans contained only a 

 small amount of visible oil, and the fish adhered to the lid of the can 

 when opened. The interior of the can was detinned to a greater 

 extent in this lot than in any of the others. The results of these 

 analyses are given in Table 31. 



Table 31. — Ammonia and amine content of sardines after long periods of storage. 



Condition offish. 



Best grade, packed 2 and 

 held 2 years. 



Poorer grade,packed and 

 held 2 years. 



Packed 

 years. 



Packed 

 years. 



and held 4 



and held 6 



P.ct. 



(55. 88 



154. 15 



(57 A 

 \55. '. 



/50. 01 



J57/ 



P.ct. 



20.73 

 21.76 



18.73 

 20. 9i 



33. 60 



Total volatile 

 nitrogen (N) 

 per 100 grams, 

 by— 



Mg. 



46.6 

 40.8 



39.6 

 43.1 



Mg. 



17.3 

 17.4 



14.7 

 18.9 



14.0 



Mg. 



29.3 

 23.4 



24.9 

 24.2 



.Total volatile 



nitrogen (N) 



per 100 grams, 



as 1 — 



Mg 



46.9 

 46.6 



44.7 

 37.7 



37.2 

 45.9 



51.1 



69. 3 



Mg. 



20.1 

 15.6 



17.8 

 5.0 



5.9 



6 4 



Mg. 



26.8 

 31.0 



26.9 

 32.7 



31.2 

 39.5 



42.5 

 (?) 



Percent 



age of 



total as— 



42.9 

 33. 5 



P.ct. 



57.1 

 66.5 



39.8 60.2 

 13.3 86.7 



15.9 

 13.9 



84.1 

 86.1 



Appearance. 



Good; slightly colored, 

 apparently by iron: 

 lid badly detinned. 



1 Particularly bright and 

 ( firm. 



I Very poor; soft white 

 material, probably 

 stearin, spread over 

 fish. 



Poor, covered with 

 white material; small 

 amount of visible oil; 

 fish adhered to lid; 

 large amount of de- 

 tinhing. 



1 Determinations and separations made on 50-gram samples. 



2 Determinations made on 3-gram samples. 



3 Lost. 



The results show that a change in the relative amount of ammonia 

 and amines occurred, the degree depending on the time the fish 

 remained in storage. The total amount of alkaline material was 

 quite constant in the 2-and 4-year-old goods, but increased noticeably 

 in the 6-year-old pack. The quantity of ammonia, both in the actual 

 amount obtained and in the percentage of the total volatile nitrogen, 

 decreased, while the amines increased directly with the age of the 

 goods. Eliminating one determination, which shows a very low 

 ammonia content on the 2-year-old packs, the average percentage 

 amount of the total was 38.7, while the three determinations on the 

 4-and 6-year-old packs showed only 15.5 per cent of the total alkaline 

 material as ammonia, with a corresponding increase of from 61.3 to 

 84.5 per cent, respectively, in nitrogen as amines. 



An experiment was conducted to ascertain whether these changes 

 in the canned fish could be followed during shorter periods of standing 

 at ordinary room temperature. A pack of a little more than half a 

 case of quarter oils was made from fish which had just been landed 



