Individual cans of experimental brine pack tuna had oil contaits varying 

 all the way from lo7 to 13.5 percent, a difference of eight times. 

 Packing the tuna in oil resulted in the absorption of considerable vege- 

 table oil into the flesh. Thus of the oil pack samples examinedj oil 

 content of the flesh varied from 9.2 to 20.2 percent. 



Those samples of brine pack tuna having very low oil content dif- 

 fered from the ordinary oil pack to a very marked extent and when exam- 

 ined by tasting panels could be readily distinguished. For example, 

 a low oil conteit brine pack and a normal oil pack of tuna were made 

 into two casserole dishes with spaghetti. A taste panel examined these 

 two dishes without knowing their identity. All eleven members of the 

 panel individually picked out the oil pack as being preferred, even 

 though the tuna was greatly diluted by the presence of the spaghetti. 

 While the difference was not pronounced, it was completely distinguish- 

 able. From an orgsinoleptic standpoint, the difference between oil and 

 brine packs seens to be a matter of a greater oily texture of the oil 

 pack. This texture difference is not so much a matter of tenderness 

 or toughness of the fLesh as it is of a difference in the feel of high 

 and low oil content flakes of fish when held on the tongue. When the 

 texture of oil and brine packs are measured with a penetrometer, the oil 

 packs are only sli^tly more tender than the brine packs. Brine packs 

 had an average penetrometer reading of 10.6 as compared to 11.8 for oil 

 packs o This relatively small difference in no way accounts for the very 

 definite difference noted organoleptically. 



A nimor to the effect that brine packs of tuna toughen upon pro- 

 longed storage was investigated. Preliminary findings Imore prolonged 

 storage tests are still underway) indicate that both brine and oil 

 packs show an increase in t outness in the first few weeks after th^ 

 are canned. Thus iranediately after being canned, brine packs of tuna 

 had an average tenderometer reading of 16. 4 and oil packs prepared 

 from adjacent sections of the same loins had a reading of 15.9. Six 

 weeks after the tests began, the readings had decreased to 13.4 and 

 13,2 respectively. Tests on other tuna, which had been put up for a 

 period of many months, showed average readings of 10.6 for brine packs 

 and 11,8 for oil packs. There was no significant difference in the 

 readings for tuna held for six months as compared to readings on samples 

 held for one or two years. Apparently increasing tou^ness is a change 

 v*iich takes place during the first few months of storage, and probably 

 the texture has already reached its maximum toughness by the time the 

 pack reaches the consumer, 



323 



