• Non ci sono risultati.

Survival of Listeria monocytogenes in Food Residues on Packaging Materials for Dairy Products

N/A
N/A
Protected

Academic year: 2021

Condividi "Survival of Listeria monocytogenes in Food Residues on Packaging Materials for Dairy Products"

Copied!
2
0
0

Testo completo

(1)

22 July 2021

AperTO - Archivio Istituzionale Open Access dell'Università di Torino

Original Citation:

Survival of Listeria monocytogenes in Food Residues on Packaging Materials for Dairy Products

Terms of use:

Open Access

(Article begins on next page)

Anyone can freely access the full text of works made available as "Open Access". Works made available under a

Creative Commons license can be used according to the terms and conditions of said license. Use of all other works

requires consent of the right holder (author or publisher) if not exempted from copyright protection by the applicable law.

Availability:

This is the author's manuscript

(2)

"Survival of Listeria monocytogenes in Food Residues on Packaging Materials for Dairy Products"

Pierluigi Di Ciccio, Francesco Chiesa, Ausilia Grassi, Selene Rubiola, Tiziana Civera

Dipartimento di Scienze Veterinarie, University of Turin, Largo P. Braccini 2, Grugliasco, TO 10095, Italy

L. monocytogenes (L.m) is known for causing foodborne infections often associated with a high mortality rate. Survival

under adverse conditions of L.m for extended periods of time has been largely reported. L.m contamination in dairy

products may be transferred on packaging materials which could then potentially serve as source of cross-contamination

in the home.

The purpose was to quantify the survival of L.m on packaging materials soiled with cheese purge and stored at different

temperatures.

Three materials, used for packaging of dairy products, with different physico-chemical properties:

poly-coated

materials

(

polythene/parchment paper - A; polythene/polyamide - B) and parchment paper - C were selected. Each material (5x5

cm) was inoculated with a 5-strain mixture of L.m (2.5 log CFU/cm

2

) of dairy origin suspended in a non

sterile-homogenate, simulating cheese purge . Samples were stored for up to 56 days at 4°C, 12 and 37°C, and periodically

analyzed for L.m and total bacterial populations. Three samples were analyzed at each sampling point.

Survival of L.m varied among packaging materials as well as at different storage temperatures. Counts decreased on all

materials stored at 37°C and reached non-detectable levels on B by day 4 and on A and C by day 7. Initial levels (2.5

log CFU/cm

2

) of L.m increased to 3 log CFU/cm

2

within 4 days of storage at 12°C on A and C. After 56 days at 4 and

12 °C, L.m was recovered from all the tested materials, with counts ranging from 1.64 log CFU/cm

2

(B) to 3.24 log

CFU/cm

2

(C)

and from 0.4 log CFU/cm

2

(B)

to 3.68 log CFU/cm

2

(C), respectively.

Survival of L.m on packaging materials raises concern because consumers may not expect pathogen contamination on

the package and could consequently do nothing to prevent cross-contamination in the home environment.

Riferimenti

Documenti correlati

Moreover, we can trace the particles’ propagation outside the neutron stars’ magnetospheres through their synchrotron emission, responsible for X-ray extended features, and their

Fitting the extracted spectrum with a sample of spectra of low mass objects, we were able to classify HR 2562 B as an early T (T2-T3) spectral type, although the H broad-band

(Colour online) Reflectance spectrum of the asteroid (311999) 2007 NS2 (black dotted line) compared with average spectra for A (red), S.. (green) and S a (purple)

We further demonstrate that our results are not showing redshift trends by constraining the mass and observable bias parameters for each tested scaling relation in two

• definition of a possible strategy to be adopted for Demand Planning and Supply Planning, according to customer requirements, for future developments;

Figure 2: Variation of the water ice absorption band at 2.02 µm on Enceladus’ South Pole, for four ranges of phase angles.. LPI

In questa tesi abbiamo applicato per la prima volta il metodo RG alla gravit`a massiva nella teoria non Fierz-Pauli, abbiamo studiato la teoria dal settore IR, dove presenta

Using time- resolved high-resolution X-ray spectroscopy of a stellar flare on the active star HR 9024 observed with Chandra/HETGS, we distinctly detected Doppler shifts in S xvi,