476 STATE BOARD OF AGRICULTURE 



SUMMARY AND CONCLUSIONS 



1. Organisms resembling aerobic spore-forming soil organisms may cause 

 flat sours when gro%\Ti under anaerobic conditions, such as we have in 

 canned goods. 



2. The organisms studied are more likely to produce flat sours at room 

 temperatures than at 37° or 55°C. 



3. The organisms causing flat sours in the experiments cited are killed by 

 exposure to a temperature of 110°C. for ten minutes. 



4. The entire contents of the original cans of peas did not reach a suf- 

 ficiently high temperature or were not kept at 100° for a sufficiently long time 

 to destroy the spores of the isolated organisms. 



5. The organisms under the conditions studied are favored by temperatures 

 of 20° to 37°. Therefore flat sours may develop (1) when blanched products 

 are allowed to stand, (2) when cans are not cooled quickly after processing, 

 and (3) when storage temperature is too high. In both of the latter cases 

 the assumption is that the product is not sterile. 



6. From a scientific standpoint it would be well to sterilize all canned 

 goods, but from a practical standpoint this may not be advisable. All 

 cans, however, should be cooled rapidly after being processed and stored at a 

 low temperature. 



7. Thermophiles may cause flat sours if the temperature of the food 

 products is sufficiently high for a long enough time to allow thermophiles to 

 develop. The indications from these experiments are that this is not prob- 

 able as the thermophiles encountered did not cause flat sours. 



BIBLIOGRAPHY 



(1) Canners' Problems, Unpublished Thesis, Univ. of Illinois, 1913. 



(2) Canning of Fruits and Vegetables — Za valla, J. P., p. 53, John Wiley 



and Sons. N. Y., 1916. 



(3) Canning and Preserving of Food Products — Duckwall, E. W., pp. 348- 



354 and 369, Pittsburgh Printing Co., Pittsburgh, Pa., 1905. 



(4) Journal of Bacteriology, Vol. I, 1916, pp. 273-321 and 493-533. 



