April 1951 COMMERCIAL FISH3RIES REVIEW 25 



RECOMMENDATIONS 



In order to obtain the highest quality pack of canned salmon, it is reoomnanded 

 that wherever possible unfrozen fish be used. When frozen salmon are used for can- 

 ning, the pack will always be slightly inferior even though the utmost precautions 

 are taken and the best technical knowledge is applied to the freezing and cold stor- 

 age of the fish. If such technical knowledge is used throughout the processing of 

 the fish, it should be possible to obtain a product which is perfectly marketable 

 even though slightly inferior to the best packs of unfrozen fish. Adverse quality 

 changes are greater for salmon which have been frozen for long periods even though 

 proper storage procedures are observed. For this reason it is reconmended that the 

 length of storage for the frozen fish be held to a minimum. To minimize quality 

 changes during storage, periods longer than two to three months at 0° F. are not re- 

 commended. If frozen fish must be used, it is of extreme ingjortance to use the best 

 modern knowledge of freezing and storing techniques. If such practices are ignored, 

 packs will result anywhere from being of extremely low quality to an extreme case 

 where the pa"ck is completely inedible and must be discarded or. re-processed at con- 

 siderable loss to the packer. 



REFRIGERATED LOCKER STORAGE OF FISH AND SHELLFISH 



Too frequently the locker operator and user fail to realize that 

 fish as well as other foods have a maximum storage life even in the 

 frozen state. The dry atmosphere of the storage room and the difficulty 

 encountered in sealing the product away from air contribute mojst to 

 shortening storage life. 



Several changes take place in looker storage which must be guarded 

 against by adequate packaging to exclude air. One change, common to all 

 frozen fish, is a gradual removal of moisture from the flesh over a 

 prolonged storage period in the relatively dry atmosphere of the cold- 

 storage room. This drying renders the fish tough, fibrous, and insipid. 

 The other change which occurs with certain oily fish is an oxidation 

 resulting in development of rancidity, fading or other changes in the 

 pigments of fish having colored flesh (as salmon), and development of 

 off-colors (usually yellow or brown) sometimes known as "rust." These 

 changes eventually render the fish flesh inedible. A guide by Stansby 

 and Harrison (1942) and Stanaby and Dassow (l942)for selecting a packing 

 method and estimating the storage life of frozensalt-water fishes asserts 

 that, in general, a locker storage life of at least six months may be 

 expected for the most properly packaged frozen fish. 



—Fishery Leaflet 128 



