KOURY. SPINELLI, and WIEG: PROTEIN AUTOLYSIS RATES 



TEMPERATURE 

 400r '0°'^ 



TEMPERATURE 

 40°C 



TEMPERATURE 

 50°C 



TEMPERATURE 

 300r 60° C 



200 



20 30 40 

 TIME ( MIN ) 



TEMPERATURE 

 70° C 



20 30 40 

 TIME (MIN.) 



4,0 

 50 



163 



MO 



TEMPERATURE 

 80°C 



20 30 40 

 TIME (MIN) 



Figure 1. — Protein autolysis rates of whole herring homogenates held at various pH's and temperatures. 



40 



45 



30 



!50 



re.e 



50 60 



TEMPERATURE 

 30-0 



TEMPERATURE 

 40- C 



TEMPERATURE 

 50° C 



TEMPERATURE 

 60°C 



20 30 40 

 TIME (MINI 



TEMPERATURE 

 70°C 



10 20 30 40 

 TIME (MIN 1 



TEMPERATURE 

 80° C 



10 20 30 40 

 TIME (MIN.) 



30 



50 



45 



 40 



(67 



50 60 



Figure 2. — Protein autolysis rates of eviscerated herring homogenates held at various pH's and temperatures. 



are shown in Figure 5. The pattern is similar 

 to that of whole hake, both in magnitude of ac- 

 tivity and the effects of pH and temperature. 

 Previous investigations in this laboratory (Das- 

 sow, Patashnik, and Koury, 1970) have shown 

 that hake is often infected with the parasite, 

 myxosporidian. The degree of this infestation 

 is much greater in the outside than in the inside 



hake (Patashnik, personal communication, 

 1970) . These investigators reported that infest- 

 ed hake autolyze rapidly during storage, mak- 

 ing them unsuitable for processing into blocks 

 or poi'tions. No detailed study relating to par- 

 asites was made in this study, but the similar 

 autolytic rates between whole and eviscerated 

 outside hake shows that the main source of pro- 



243 



