KUDO ET AL.: TEXTURE QUALITY OF PACIFIC WHITING 



P = 0.008). Incidences of heavy infections of black 

 pseudocysts were 2 to 3% at the nape and about 1 

 to27f atthetaiUr = 0.71 at P = 0.06). In general, 

 there tend to be more black and/or white pseudo- 

 cysts in the nape than in the tail area, although 

 the correlation of white pseudocysts in the dorsal 

 to ventral direction was rather low (r = -0.21 at 

 P = 0.035). 



Sensory texture profiles shown in Table 7 indi- 

 cated that more abnormal textures were found in 

 the nape area (11 to 8%) than in the tail area (5 

 to 4%) ofthe fish examined (r = 0.48 at P = 0.16). 



Effect of Culling 



At the present time, there is no accepted 

 method or methods for efficiently detecting and 

 culling Pacific whiting infected with white or 

 black pseudocysts. Ultraviolet light and back 

 lighting with white light have been tried on occa- 

 sion, but these techniques have not been devel- 

 oped enough to be effective for use in Pacific whit- 

 ing production. This leaves visual detection as the 

 only on-site method for detecting and removing 

 suspect Pacific whiting from the production line. 

 However, as there are no reliable data available 

 concerning the effectiveness of visual culling, an 

 attempt was made in this study to estimate its 

 potential usefulness. 



Criteria for culling (Patashnik et al. 1982) in 

 this study was described in a previous section. Of 

 the 562 fish examined, 34 were visually culled on 

 the basis of a moderate to heavy degree of white 

 and black pseudocyst infection. Of these, 10 fillets 

 were moderately to heavily infected with white 

 pseudocysts, 7 with both black and white pseudo- 

 cysts, and 17 with only black pseudocysts. Based 

 on the criteria developed by Patashnik et al. 

 (1982), these results suggest that culling fillets 

 that are moderately or heavily infected with 

 pseudocysts appears possible. However, since 

 culling has not been successfully demonstrated in 

 a commercial setting, the technique may prove to 

 be too difficult and time consuming to be practi- 

 cal. 



CONCLUSIONS 



Overall, 18^^ ofthe Pacific whiting samples col- 

 lected for this study were uninfected with Kudoa . 

 Furthermore 65^7? had counts of <10 white pseu- 

 docysts, and only 10% had counts over 100 white 

 pseudocysts. By comparison, 81% ofthe fish sam- 

 ples had <10 black pseudocysts counted and only 



1% were infected with over 100 black pseudocysts 

 counted. 



When both the white and black pseudocyst 

 counts were considered collectively, the varia- 

 tion in white pseudocysts explained 55% of the 

 variation in sensory texture, whereas black 

 pseudocysts accounted for 14%. However, when 

 the effect of the white pseudocysts was mathe- 

 matically removed from the fish samples having 

 both, the black pseudocysts were found to 

 explain only 1.5% of the variation in sensory 

 texture. 



Infections of white K. panifor/nis and white 

 mixed infections correlated (r = 0.80 and 0.79, re- 

 spectively) with the variations in sensory texture 

 better than the black K. paniformis or black 

 mixed infections (0.66 and 0.49, respectively). 

 Neither the white nor the black /if . thyrsitis pseu- 

 docyst counts correlated well with sensory tex- 

 tures. Although common in the Pacific whiting 

 samples examined in this study, K. thyrsitis con- 

 sistently were found in low numbers. On the 

 other hand, K. paniformis were identified in 26% 

 ofthe sample, and mixed infections were observed 

 in 34% of the fish examined. 



The heaviest infections of white and black 

 Kudoa sp. pseudocysts were found in the Pacific 

 whiting caught off the coast of California. The 

 highest percentage of abnormal sensory textures 

 were also observed in the fish harvested off the 

 California coast. 



Generally, in this study, we found that the 

 larger the fish the greater the incidence of abnor- 

 mal textures. Sex of the fish had no apparent ef- 

 fect on the quality of sensory texture. 



Anatomically, the nape and dorsal areas of the 

 Pacific whiting samples examined tended to have 

 higher counts of white pseudocysts, and therefore 

 more abnormal textures, than the other areas of 

 the fish examined. The occurrence of heavy white 

 pseudocyst infections in the nape, middle, and tail 

 sections ofthe fish samples averaged 11.5%, 8.5%, 

 and 8%, respectively. Heavy black pseudocyst in- 

 fections were 2.5%, 2%, and 1.5% for nape, mid- 

 dle, and tail sections. Overall, abnormal textures 

 were found 9.5% ofthe time in the nape, 6.5% in 

 the middle, and 4.5% in the tail. Differences in 

 the number of white pseudocyst counts found be- 

 tween the dorsal and ventral sides ofthe fish were 

 small. The occurrence of abnormal texture was 

 30% greater for the dorsal side ofthe fish than the 

 ventral side. 



Results of visual culling in this study suggest 

 that the method may have some potential, but 



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