FISHERY BULLETIN: VOL. 69, NO, 1 



Table 3. — Weight gain, feed intake, and protein effi- 

 ciency ratio of groups of 10 rats fed diets of FPC samples 

 prepared from red hake that were heated for varying 

 times and temperatures before being extracted with 

 solvent. 



Sample 



Average daily 

 weight gain 



Averog© daily 

 feed intake 



Protein 

 efficiency 



ratio 



that of casein. When the temperature was in- 

 creased to 121° C, the quality of the samples was 

 slightly lower than that of casein but not sig- 

 nificantly so. At each temperature, the temper- 

 ature at which the samples were heated had a 

 more significant effect on the quality of the 

 samples than did the length of time of heating. 



SUMMARY AND CONCLUSIONS 



We conducted a study to determine the chem- 

 ical composition and nutritional quality of FPC 

 produced from fish that are heated before they 

 are extracted with solvent. Red hake, which 

 are lean fish, were heated at 100° C for 10, 20, 

 40, or 80 min. Other samples were heated for 

 these same lengths of time at 109° or 121° C. 

 The samples were then e.xtracted with isopropyl 

 alcohol. The FPC produced from the samples 

 of hake that were heated contained slightly less 

 crude protein and more ash than did the FPC 

 produced from the samples that were not heated. 

 The amino acid composition of samples that had 

 been heated did not differ markedly from the 



composition of those that were not heated. The 

 nutritive quality of the samples that were heated 

 at 100° and 109° C was not significantly affected. 

 Samples heated at 121° C, however, were lower 

 in quality than was the control sample. 



We conclude that red hake can be heated at 

 temperatures of 100° and 109° C for as long 

 as 80 min before being extracted by solvent with- 

 out the quality of the protein being affected sig- 

 nificantly. 



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