GAMMA IRRADIATION OF SALMONELLA SPECIES IN FROZEN WHOLE EGG
A study was undertaken to establish the survival pattern of 18 Salmonella species in frozen whole egg exposed to gamma radiation from a Co/sup 60/ source as part of a program to investigate the possibilities of using radiation for the destruction of micro-organisms in foods. A definite variation in sensitivity to radiation was found among these 18 species commonly occurring in frozen egg. The dose levels, applied at a dose rate of 0.491 Mrad/hr, required for a 10/sup 7/-fold reduction of these species ranged from 0.36 to 0.54 Mrad. Variation in sensitivity to radiation was also detected with three cultures of S. pullorum that appeared similar except in origin. Variation in sensitivity within all species of Salmonella studied apparently indicates that no one species can be considered most resistant. These studies reveal that a level of 0.54 Mrad of gamma radiation would reduce the salmonellae to a safe level in frozen egg. However, this is based on the supposition that 10/sup 5/ cells is a reasonable number to consider necessary for the initiation of salmonellosis. The most heavily contaminated frozen egg melange examined contained approximates 2 x 10/sup 5/ cells of salmonellae/ml. Of these, any process giving a 10/sup 7/-fold reduction would leave only 2 x 10/sup -2/ cells/ml, i.e., 2 cells/100 ml or about 10 cells per lb. Apparently it would be necessary to consume several tons of uncooked melange to obtain an infective dose and therefore the 10/sup 7/-fold reduction is adequate from the viewpoint of the public health hazard. Although off-flavors develop in frozen whole egg irradiated with 0.5 Mrad, they disappear on storage and the irradiated product was found acceptable for commercial use. Thus irradiation of frozen whole egg melange with 0.54 Mrad would not be expected to markedly increase the unfavorable alterations in the product, indicating that gamma radiation possesses a distinct potential for removing Salmonella from frozen whole egg melange. (BBB)
- Research Organization:
- Ontario Agricultural Coll., Guelph
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-18-000522
- OSTI ID:
- 4167142
- Journal Information:
- Canadian Journal of Microbiology (Canada), Vol. Vol: 9; Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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