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Death rates of salmonellae in fishmeals with different water activities I.—During storage
Author(s) -
Doesburg J. J.,
Lamprecht E. C.,
Elliott M.
Publication year - 1970
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740211208
Subject(s) - salmonella , zoology , nitrogen , chemistry , biology , food science , veterinary medicine , bacteria , medicine , genetics , organic chemistry
Fishmeals with different moisture contents, having water activities ( a w ) ranging from 0.34 to 0.71, were infected with strains of Salmonella oranienburg or S. senftenberg and were stored at 15, 20 and 30°c, packed in nitrogen or air. The initial death rates (calculated over storage periods of 70 days) were not appreciably influenced by reduction of a w from 0.71 to 0.54. Further reduction of a w to 0.34 caused a decrease of the initial death rate, in particular in meals stored at 15 or 20°c. As compared with fishmeals packed in air, meals packed in nitrogen showed a decrease of initial death rates, especially in meals with the lowest a w and stored at 15 and 20°c. Death rates calculated over longer storage periods were smaller than initial death rates, in particular in meals with a w 0.54 stored at 15 and 20°c and meals with a w 0.34 stored at 15, 20 and 30°c. Pelletisation of meals with a w 0.72‐0.74 caused a 10 2 ‐10 3 ‐fold reduction of initial Salmonella counts. The death rates of salmonellae which survived the pelletisation treatments were of about the same order as found for the initial death rates of salmonellae in non‐pelletised meals with about the same a w .