Thermal death times of Hafnia alvei cells in a model suspension and in artificially contaminated hot-smoked kahawai (Arripis trutta).
In New Zealand the product most frequently implicated in cases of scombroid poisoning is hot-smoked kahawai (Arripis trutta). Using a Hafnia alvei strain, previously isolated from a portion of hot-smoked kahawai with a histamine level of 1,659.4 mg/kg, thermal death trials were carried out in a model suspension (0.1% peptone) at 54, 55, 56, 57, and 58 degrees C. From the linear regression line (R2 = 0.98) fitted to observed D values plotted against temperature, calculated D values for 54, 55, 56, 57, and 58 degrees C were estimated to be 0.63, 0.36, 0.20, 0.11, and 0.06 min, respectively, giving a z value of 4.14 degrees C. Thermal death trials were also carried out for H. alvei associated with hot-smoked kahawai at 54, 55, 55.5, 56, and 57 degrees C. From the linear regression line (R2 = 0.93) fitted to the data, calculated D values for 54, 55, 56, and 57 degrees C were estimated to be 1.42, 0.74, 0.38, and 0.20 min, respectively, giving a z value of 3.57 degrees C. Results indicate that hot smoking has the potential to eliminate H. alvei from seafood products.
Seafood Research Unit, New Zealand Institute for Crop & Food Research Ltd, Port Nelson, New Zealand. bremerp@crop.cri.nz
P J
PJ
Bremer
C M
CM
Osborne
R A
RA
Kemp
P
P
van Veghel
G C
GC
Fletcher
D004755:Enterobacteriaceae / Q000502:physiology*; D005396:Fish Products / Q000382:microbiology*; D006632:Histamine / Q000096:biosynthesis; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D013242:Sterilization; D013535:Suspensions; D013997:Time Factors
D013535:Suspensions; D006632:Histamine