July 1951 



COmEECIAL FISHERIES REVIEW 



LABORATORIES 



June 1951 



REFRIGERATION ; Freezing-Flah-At-Sea ; In order to test on a commercial scale 

 the freezing of round (inftiole) fish at sea for later defrosting, filleting, and re- 

 freezing ashore, a surplus trawler, the IS/V Delaware was obtained from another 

 goTei-miiental agency, The Delaware was received in Boston in December I95O. During 

 the past several months the vessel was overhauled, reconditioned, and outfitted. 

 Fish-handling and refrigeration test eq^uipment was installed, the captain and crew 

 were recruited, and on June I9 the vessel left for its first or "shakedown" cruise 

 to the Georges Banks fishing grounds. The Delaware returned to Boston on June 23. 



Vessel and gear were in good order, and fish-handling and refrigeration eq^uip- 

 ment seemed to operate satisfactorily as far as could be determined. The Diesel 

 generator, which furnished power for the foregoing equipment, did not operate satis- 

 factorily and will be replaced before the next voyage is made. A number of other 

 alterations and adjustments will also be necessary. 



Approximately 6,000 pounds of fish were landed of iitoich 1,000 pounds were fro- 

 zen at sea for experimental use. (Boston) 



Freezing and Storing Alaska Shrimp and Dungeness Crab ; Frozen Alaska shrimp 

 were examined after storage at 0° F, for seven months. The highest -quality pack was 

 that in which raw shrimp tails were frozen in either sealed cans or as a glazed 

 block, and their storage life was greater than 7 months at 0°F. 



Coon-stripe (Pandalus hyainotus ) and side-stripe ( Pandalopsis dispar ) shrimp 

 which were precooked for 4 minutes, peeled, packaged in sealed cans, and frozen were 

 rated unmarketable or on the borderline. Their storage life was less than 7 months 

 at 0° F. 



Examination of two packs of side-stripe shrimp which were precooked for 4 min- 

 utes, peeled, packaged and frozen in vacuum-sealed cans and in plastic-top cans 

 showed that the vacuum pack was definitely superior in color and flavor. However, 

 the vacuum-packed shrimp had a flat flavor and lacked a desirable crisp texture. The 

 storage life of these shrimp was a little over 6 months at 0° F. (Ketchikan) 



Studies on Methods of Handling Frozen Salmon for Canning : The second examina- 

 tion of canned, frozen sockeye salmon, prepared from salmon taken in Southeastern 

 Alaska during the I950 season, was carried out. 



This examination reaffirmed the results reported earlier. Sockeye salmon fro- 

 zen at -20° F, and stored at that temperature for 22 weeks prior to canning were not 

 noticeably higher in quality than the same fish frozen at -20° F. and stored at 0° F . 

 for 22 weeks. In both cases the Ltuality was markedly reduced as compared to the 

 fresh-canned fish. Excessive curd and toughening as well as a reduced amount of 

 free oil and liquid and slight off -odor, color, and flavor were noticeable in both 

 experimental packs. (Ketchikan) 



