New York Agricultural Experiment Station. 



8i 



would indicate that this temperature marlced about the limit of re- 

 sistance on the part of the germ. Variations in the age of the peas, 

 in the density of the same in the cans, and other like factors would 

 then show their maximum influence on the results of the heating. It 

 should also be remembered that in the experimental cans the amount 

 of infection was much greater than would be expected in nature, and 

 the chance of an unusually resistant spore surviving was correspond- 

 ingly increased. 



In the same factory where the heating at 230° F. for 30 minutes 

 had failed so completely a heating at 238° F. for 35 minutes gave 

 good results, the loss being no greater than that ordinarily attributed 

 to leaks in the cans. 



Two Pound Cans of Peas Heated to 240° F. at Laboratory. 



Time in minutes. . . 

 No. cans heated. . . 

 No. cans swelled. . . 

 Percentage swelled 



30 

 36 



o 







The results at 240° F. are very uniform. This uniformity is more 

 striking from the fact that cans were tested at this temperature on the 

 same days, inoculted with portions of the same culture as that used 

 in three of the tests at 236° F. where the results were so irregular. 

 It would seem that 240° F. quickly destroys the germs but the num- 

 ber of cans is so small that it would not be safe, on the basis of these 

 figures, to risk processing at this temperature for less than 20-25 

 minutes. 



The effect upon the commercial quality of a short exposure to 240° 

 F. has not been accurately determined and there seems to be a dif- 

 ference of opinion upon this point among canners. It is probable 

 that at least within some grades of peas this is very close to the limit 

 of the heating compatible with a first-class product. 



