Modelling the behaviour of Listeria monocytogenes in ground pork as a function of pH, water activity, nature and concentration of organic acid salts.
OBJECTIVE
to study and model the effect of sodium acetate, sodium lactate, potassium sorbate and combination of acid salts on the behaviour of Listeria monocytogenes in ground pork.


RESULTS
Water activity (a(w)), pH and concentration of acid salt of the meat were adjusted. The behaviour of inoculated L. monocytogenes was studied and modelled according to physicochemical parameters values. Whatever the acid salt concentration used, we observed an inhibition of the growth of L. monocytogenes at pH 5.6 and a(w) 0.95. At pH 6.2 and a(w) 0.97, addition of 402 mmol l(-1) of sodium lactate or 60 mmol l(-1) of potassium sorbate was required to observe a slower growth.


CONCLUSIONS
The inhibitory effect of acid salts was a function of pH, a(w), as well as of the nature and concentration of acid salts added. When one acid salt was added, the Augustin's model (Augustin et al. 2005) yielded generally correct predictions of either the survival or growth of L. monocytogenes.


CONCLUSIONS
The suggested model can be used for risk assessment concerning L. monocytogenes in pork products.
Zuliani
V
V
IFIP-Institut de la filière porcine Antenne de Maisons-Alfort, Maisons-Alfort, France. veronique.zuliani@ifip.asso.fr
Lebert
I
I
Augustin
J-C
JC
Garry
P
P
Vendeuvre
J-L
JL
Lebert
A
A
D000818:Animals; D015169:Colony Count, Microbial; D005516:Food Microbiology; D005520:Food Preservatives / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects*; D008433:Mathematics; D008460:Meat / Q000382:microbiology*; D008954:Models, Biological; D012492:Salts / Q000494:pharmacology; D019346:Sodium Acetate / Q000494:pharmacology; D019354:Sodium Lactate / Q000494:pharmacology; D013011:Sorbic Acid / Q000494:pharmacology; D013552:Swine; D014867:Water / Q000378:metabolism
D005520:Food Preservatives; D012492:Salts; D014867:Water; D019346:Sodium Acetate; D019354:Sodium Lactate; D013011:Sorbic Acid