HANDLING AND TRANSPORTING TU THE CANNERY 

 Part B 



by 

 Sven Lassen 1/ 



The technological problems which I shall discuss are some which I have had a 

 chance to study as a result of my contract with the Bureau of Commercial Fisheries. The 

 title of the contract is: "A Study of Methods of Handling, Freezing and Thawing of Tuna 

 at Sea, and the Resulting Effect on Quality and Yield of the Canned Product." To do 

 justice to a project like this, it is, of course, necessary for the investigator to have 

 a fairly clear picture of what happens to a tuna from the moment it hits the deck of the 

 tuna clipper until it ends its usefulness in the form of a tasty dish on the consumer's 

 table. Of course the part of the overall processing of tuna which takes place at the 

 shoreside cannery may more readily be subjected to a study and analysis, and that is why 

 more is known about the influence upon quality and yield of handling during the shoreside 

 processing of tuna. While we have studied some important aspects of this last phase of 

 tuna processing, it is what happens to the quality and yield of tuna during the transit 

 period from the fishing area to the home port of the tuna clipper that I should like to 

 say something about. 



To learn more about the procedure 

 followed by the tuna clipper for the pres- 

 ervation of tuna while in transit, a survey 

 covering 103 tuna clippers was made by 

 Mr. Van Atta of the California State Board 

 of Health, and paid for by the Bureau of 

 Commercial Fisheries. I had the privilege 

 of analyzing and summarizing the results 

 of this survey. While much useful knowl- 

 edge was gained of the various steps 

 involved in the treatment of tuna on board 

 ship, it became evident from this survey 

 that the methods of preservation, while 

 similar in outline, varied enough in es- 

 sential detail that a picture of a uniform 

 procedure could not be obtained. This 

 explains in part why some boats bring in 

 better fish than othdrs. To clarify this 

 situation and at the same time try to unify 

 preservative methods on board the tuna 

 clippers, an attempt was made to write a 

 set of general recommendations which, if 

 followed, would give a uniform, improved, 

 high quality tuna product delivered at the 

 dockside. These recommendations were 



1/ Director, Philip R. Park Research 

 Foundation, San Pedro, California. 



embodied in a manual. The recommendations 

 were based upon the valuable advice and 

 help by many people with whom Mr. John 

 Rawlings, my collaborator in this effort, 

 and I came into contact. 



As a part of the effort to learn more 

 about what happens to the tuna on board 

 ship, Mr. Rawlings made observations and 

 measurements at sea on the treatment of* 

 tuna in transit. The results from the two 

 cruises of Mr. Rawlings have been reported 

 in various communications from the Bureau 

 of Commercial Fisheries, and will not be 

 delt with here to any extent. Mention 

 shall only be made of the temperature meas- 

 urements of the freshly-caught tuna on deck 

 and in the filled wells of the tuna clipper 

 which contributed much to a better under- 

 standing of the problem. 



One might ask what is the nature of 

 the changes which freshly-caught tuna 

 undergo when stowed in the wells of a tuna 

 clipper and kept under refrigeration while 

 being transported to the cannery. These 

 changes apparently begin the moment the 

 tuna hits the deck and continue at various 



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