92 



BULLETIN 908, U. S. DEPARTMENT OF AGRICULTURE. 



the analyses of the different lots of fish packed without oil agreed 

 very well with the results on the packs in oil, about the same quan- 

 tity of ammonia being found in both cases. These results show that 

 canned sardines contain more ammoniacal material than the fresh 

 fish. 



Table 40. — Total volatile nitrogen {ammonia and amines) on water and fat free basis in 



packs with and 'without oil. 1 



Condition of fish. 



Total volatile ni- 

 trogen (ammonia 

 and amines) on 

 water and fat 

 free basis per 100 

 grams. 



Fresh (3 hours out of water): 



Not in pickle 



In pickle — 



30 minutes 



1 hour 



14 hours 



2 hours 



12 hours old: 



Not in pickle 



In pickle — 



30 minutes 



1 hour 



14 hours 



2 hours 



24 hours old: 2 



Not in pickle 



In pickle— 



30 minutes 



1 hour 



1| hours 



2 hours 



207.0 



194.0 

 173.0 

 217.3 

 199.0 



221.0 



206.3 

 201.0 

 189. 3 

 177.0 



1 These sardines had been packed about 7 months. - Same as lot of fish given in Table 38. 



In the case of fish which had undergone an excessive decomposition 

 the results point to the possibility of detecting this degree of spoilage 

 in the packed goods. The length of time in pickle had a more 

 marked influence on the ammonia content when the fish were in an 

 advanced stage of decomposition than when they were fresh. 



The determination of volatile alkaline material, expressed in terms 

 of ammonia and amines, in the canned product, therefore, becomes of 

 doubtful value as a means for detecting decomposition of a less 

 degree in fish which have been in salt or pickle. 



The process of pickling and salting the fish is subject to extreme 

 variations. There is no uniformity in the length of time the fish 

 remain in pickle, in the degree of salinity of the pickle, in the amount 

 of salt used in dry salting, in pumping off the brine formed when the 

 fish are dry salted, or in the length of time of processing, all of which 

 have a marked effect upon the ammonia and amine content of canned 

 fish. In consideration of these factors it would be impossible to gage 

 the extent of decomposition undergone by the commercial canned 



