New Federal Standards for Tuna 



In 1925 the Bureau of Chemistry, United States Department of Agri- 

 culture, following meetings with the tuna industry, published in its 

 Trade Announcements, certain recommendations on the canning of tuna. In 

 part, the recommendations for the No« -g^-tuna cans called for a drained 

 weight of not less than ^-3/h ounces for hand-packed, solid-pack tuna. 

 (Machine packing was not used at that time and the chunk and flalce type 

 packs were not marketed.) Apparently these recommendations were satis- 

 factory as long as the solid-pack tuna was hand packed. However, when 

 the chunk and flake style packs were introduced and the machine packing 

 began to replace hand packing the absorption of oil by the tuna no "long- 

 er followed a fixed pattern. Machine packed tuna because of its twisted 

 or distorted fibers absorbs more oil than the hand packed product. Simi- 

 larly chunk-pack and flake-pack tuna absorb more oil than the solid-pack. 

 Therefore, the drained weight procedures pre^.dously used to denote the 

 "fill-in" weight of tuna were no longer applicable. 



During the past several years the Federal Food and Drug Admihis- 

 tration has again been working closely with the tuna industry toward 

 the eventual setting up of standards for canned tuna. Thousands of 

 laboratory tests have been carried out on such subjects as fill of con- 

 tainer and methods of determining it, and on color determination of the 

 canned product. At the present time these discussions and experiments 

 have nearly been concluded. Although the final specifications have hot 

 been resolved, tentative specifications are under consideration and it is 

 expected that the final specifications may be adopted sometime during 

 1953= One of the particularly important problems in standardizing canned 

 tuna products involves the matter of fish "fill-in" weight of the contain- 

 er. For example, packers have been putting about 5-3/ii ounces of fish 

 into hand-packed No. ■§• tuna cans which are labeled "net contents 7 ounces." 

 Machine-packed No. f cans may have ^2 ounces "fill-in" weight and sometimes 

 even less. (These "fill-in" weights represent the precooked loins - not 

 the raw meat, 5 The fish absorbs sufficient added oil to give a higher 

 drained weight with the machine-packed than with hand-packed fish. Similar 

 relationships hold for the other types of packs. 



The ordinary drained weight determination is carried out as follows s 

 The canned product is opened and the contents of the can are placed on a 

 standard gauge wire screen. The material is allowed to drain a specified 

 time and the solid material weighed. The weight of the solid material is 

 called the "drained weight." The drained weight is an estimation of the 



3U 



