THE CANNED PEA INDUSTRY 51 



a brighter can. Cans heated gradually by turning 

 steam on slowly have a clearer liquid than when 

 steam is turned on suddenly at full pressure. Very 

 quick heating injures the peas in contact with the 

 can, and also causes a blackening inside of the can. 

 As the calcium system is maintained at a high heat 

 the effect upon the peas is more like that of the 

 quick dry steam. Sterilization is effective in either 

 of the three processes. 



The experienced packer cools the cans immedi- 

 ately after taking from the processing vats. If cans 

 are only slightly cooled and stacked in large quan- 

 tities, those in the center will retain heat for many 

 days. This will tend to break down the peas, and 

 injure their final appearance as they come onto the 

 table. Cooling prevents this. Then, too, it aids in 

 prompt detection of leaks. 



Peas Spoiling". All factories face the possibility 

 of more or less loss through spoilage. This may 

 be due to insufficient processing, to leaks in the can, 

 or possibly spoilage prior to the canning. Hard- 

 ing and Nicholson 3 report studies of bacteria caus- 

 ing serious losses in canned peas. In general, the 

 spoiled cans presented a bulged appearance, and in 

 some cases were actually broken open. The peas 

 had a disagreeable odor, suggesting hydrogen sul- 

 phide. They were mushy, skins were inflated, and 

 liquor was darkened and of a greenish tinge, due to 

 the particles of the ruptured peas. A microscopical 

 examination of the juice showed that the cans in 

 which the disagreeable odor was noticed carried 

 bacteria, which survived the heat employed in proc- 



8 N. Y. Exper. Sta., Bui. 249, pp. 153-168. 



