Table 4. — The effects of premortem stress, holding temperatures, and freezing on the organoleptic quality of 



canned skipjack tuna. 



Treatment 



Life fish, 0° brine 

 32° F-R-F-6 hr . . 

 32° F-R-UF-6 hr 



Control, R 



32° F-S-F-6 hr . . 

 32° F-S-UF-6 hr 



Control, S 



78° F-R-F-6 hr . . 

 78° F-R-UF-6 hr 



Control, R 



78° F-S-F-6 hr . . 

 78° F-S-UF-6 hr 



Control, S 



60° F-R-F-6 hr . . 

 60° F-R-UF-6 hr 



Control, R 



60° F-S-F-6 hr . . 

 60° F-S-UF-6 hr 



Control, S 



78° F-R-F-9 hr . . 

 78° F-R-UF-9 hr 



Control, R 



78° F-S-F-9 hr . . 

 78° F-S-UF-9 hr 



Control, S 



Freeze control, R 

 Frozen control, S 



Score' 



Scorch 



1.0 

 1.0 

 2.8 

 2.6 

 1.4 

 2.6 

 2.4 

 3.8 

 4.3 

 3.0 

 3.0 

 3.0 

 3.2 

 3.2 

 3.2 

 2.8 

 3.4 

 1.8 

 3.2 

 2.2 

 1.6 

 2.8 

 3.0 

 2.8 

 3.2 

 2.4 

 1.0 



Color 



Odor 



Flavor 



Flakiness 



Firmness 



1.6 

 4.5 

 5.6 

 3.2 

 4.2 

 3.8 

 3.0 

 4.0 

 6.0 

 3.4 

 4.8 

 3.3 

 3.4 

 3.2 

 3.0 

 3.0 

 1.4 

 2.2 

 2.8 

 2.0 

 2.6 

 3.0 

 2.2 

 2.8 

 2.8 

 1.8 

 1.0 



3.6 

 2.8 

 3.6 

 2.4 

 3.0 

 2.6 

 2.4 

 4.6 

 3.5 

 2.6 

 2.8 

 2.3 

 3.2 

 3.6 

 3.4 

 2.6 

 3.2 

 1.8 

 2.2 

 2.8 

 3.2 

 2.6 

 3.0 

 3.6 

 2.2 

 3.2 

 2.0 



3.2 

 4.5 

 3.4 

 2.6 

 2.8 

 3.0 

 2.2 

 3.4 

 3.3 

 2.6 

 2.4 

 2.0 

 2.8 

 3.2 

 3.6 

 2.4 

 2.4 

 2.2 

 2.0 

 2.8 

 3.6 

 2.4 

 2.6 

 2.8 

 2.0 

 2.6 

 1.0 



6.4 

 5.8 

 4.4 

 4.0 

 6.6 

 3.4 

 3.8 

 6.2 

 6.3 

 3.6 

 5.2 

 5.3 

 4.8 

 6.0 

 5.4 

 2.8 

 5.6 

 3.4 

 3.4 

 7.2 

 5.4 

 2.8 

 7.6 

 7.2 

 3.4 

 5.0 



6.6 

 6.5 

 6.2 

 4.0 

 6.6 

 3.4 

 3.4 

 6.2 

 5.3 

 4.8 

 7.2 

 5.7 

 5.0 

 7.2 

 4.8 

 2.2 

 6.8 

 4.8 

 3.4 

 6.4 

 6.0 

 2.2 

 7.0 

 6.8 

 4.8 

 7.8 



Fibers 



5.6 

 7.3 

 6.6 

 5.0 

 6.4 

 6.2 

 5.4 

 5.4 

 7.3 

 8.2 

 6.8 

 6.3 

 6.4 

 7.2 

 7.4 

 7.2 

 4.8 

 6.0 

 6.6 

 6.6 

 5.6 

 7.2 

 4.6 

 5.4 

 6.0 

 5.6 



' See Table 1. 



stressed) were less firm and more flaky (less 

 cohesive) than any of the fish in other treat- 

 ments. Nearly all of the fish that were frozen 

 after holding were firmer and more cohesive 

 in texture than the fish that were held and not 

 frozen. The observation of the effects of freez- 

 ing on flakiness and firmness more or less 

 agrees with that of Crawford et al. (1970). 



Fibers.— The fish held in 32° F RSW, 60° F 

 RSW (rested), and 78° F SW for 6 hr showed 

 a tendency to be fibrous (chewy). It is inter- 

 esting to note that there is no agreement in 

 the unfrozen controls, which show a wide range 

 in this characteristic, with the rested controls 

 being generally more fibrous. 



Off odor and flavor. — There are some no- 

 table general trends in the development of off 

 flavor and odor. However, the most significant 



observation is that the control fish (especially, 

 the frozen stressed controls) were generally 

 scored as having more off flavor and odor than 

 the fish that was held at the various temper- 

 atures before canning. Presumably by defini- 

 tion, off odor and flavor are those attributes 

 not typical or characteristic of fresh fish that 

 has been properly handled and processed. Most 

 assuredly, no commercial procedure could 

 match the care and expediency achieved in the 

 catching, handling, and processing of the con- 

 trols in this experiment. Furthermore, since 

 those fish (controls) presumably represent the 

 epitome of freshness and good handling and 

 processing and since the panel of expert judges 

 was not considering preference, then one must 

 conclude that: 



Fresh skipjack contains inherently objec- 

 tionable flavors and odors in which case some 

 pretreatment is necessary to achieve a prod- 

 uct devoid of these adverse characteristics. 



20 



