title: Determination ofListeria monocytogenesGrowth during Mushroom Production and Distribution.
abstract: In the EU, food is considered safe with regard toListeria monocytogenesif its numbers do not exceed 100 CFU/g throughout the shelf-life of the food. Therefore, it is important to determine if a food supports growth ofL. monocytogenes. Challenge studies to determine the ability of a food to support growth ofL. monocytogenesare essential as predictive modelling often overestimates the growth ability ofL. monocytogenes. The aim of this study was to determine if growth ofL. monocytogeneswas supported during the production and distribution of mushrooms. A three-strain mixture ofL. monocytogeneswas inoculated onto three independent batches of whole mushrooms, sliced mushrooms, mushroom casing and mushroom substrate at a concentration of about 100-1000 CFU/g. The batches were incubated at potential abuse temperatures, as a worst case scenario, and at intervals during storageL. monocytogenesnumbers, % moisture and pH were determined. The results showed that the sliced and whole mushrooms had the ability to support growth, while mushroom casing allowed survival but did not support growth. Mushroom substrate showed a rich background microflora that grew onListeriaselective media and this hindered enumeration ofL. monocytogenes. In the case of this study, Combase predictions were not always accurate, indicating that challenge studies may be a necessary part of growth determination ofL.monocytogenes.
authors.affiliation: Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. dara.leong@teagasc.ie.
authors.forename: Dara
authors.initials: D
authors.lastname: Leong
authors.affiliation: Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.
authors.forename: Avelino
authors.initials: A
authors.lastname: Alvarez-Ordóez
authors.affiliation: Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. floriane.guillas@sfr.fr.
authors.forename: Floriane
authors.initials: F
authors.lastname: Guillas
authors.affiliation: Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. kieran.jordan@teagasc.ie.
authors.forename: Kieran
authors.initials: K
authors.lastname: Jordan
keywords: Listeria monocytogenes; challenge tests; food safety; growth; mushrooms