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GROWTH OF STAPHYLOCOCCUS AUREUS AND ENTEROTOXIN A PRODUCTION IN FOODS CONTAINING POLYPHOSPHATES
Author(s) -
SHELEF LEORA A.,
WANG ZHILING,
UDEOGU ANTHONY C.
Publication year - 1989
Publication title -
journal of food safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 43
eISSN - 1745-4565
pISSN - 0149-6085
DOI - 10.1111/j.1745-4565.1989.tb00021.x
Subject(s) - enterotoxin , staphylococcus aureus , food science , chemistry , incubation , sodium , pyrophosphate , biochemistry , bacteria , biology , enzyme , escherichia coli , genetics , organic chemistry , gene
Effects of pyro‐, tripoly‐ and hexametaphosphates (0.5 and 1%, w/w) on growth of Staphylococcus aureus strain 196E and enterotoxin A (SEA) production were studied in cooked custard and beef at 22 and 30°C. No effect was observed in custard, where cell numbers/g increased from 10 3 to 10 8 and SEA reached 4.2 ng/g after 48 h at 22°C, irrespective of treatment. Cell numbers in cooked beef were ca. 10 9 /g after 48 h, and reduced numbers (by 1.5–2 log cycles) were found in samples containing 0.5 and 1% pyrophosphate during incubation at 22%, but not at 30°C. SEA concentrations in beef were 28 ng/g after 48 h at 22°C, and 93 and 184 ng/g after 24 and 48 h, respectively, at 30°C. SEA concentration correlated with amount of growth, and was nondetectable when cell numbers were ± 10 6 /g. Reduction of the meat pH by sodium acid pyrophosphate contributed to the observed inhibitory effect.