Introduced Organisms Recovered 



Sterility. A can of salmon examined in this experiment was de- 

 termined to be sterile when the meat and juice cultures incubated in 

 the petri dish produced less than three colonies of any one bacterium, 

 when a spreader was present which was the result of less than three 

 colonies, when the mass culture showed sterility, and when no gas was 

 produced in the anaerobic culture tube. In the case of the meat and 

 juice petri plate cultures, the one or two colonies found at times 

 may have been caused by an error in the technique, unsterile media, 

 or an organism may have fallen into the plate. Thus judgment was 

 somewhat reserved. The following table gives the results of the 

 experimental pack : 



NON-STERILE CANS IN EXPERIMENTAL PACK 



From the above it appears that about 77 per cent of the 45-minute 

 process were non-sterile, 22 per cent of the 60-minute process, 14 

 per cent of the 75-minute process, and 9 per cent of the 90-minute 

 process. These results compare favorably with the results obtained 

 in the National Canners' laboratory at Seattle. It should be remem- 

 bered that this experimental pack was put up under the same condi- 

 tions that prevail in the average salmon cannery. The fish used 

 were somewhat older than those usually canned in a commercial 

 plant, giving more chance for bacterial infection. 



115 



