The impact of a cold chain break on the survival of Salmonella enterica and Listeria monocytogenes on minimally processed 'Conference' pears during their shelf life.
BACKGROUND
In recent years, improved detection methods and increased fresh-cut processing of produce have led to an increased number of outbreaks associated with fresh fruits and vegetables. During fruit and vegetable processing, natural protective barriers are removed and tissues are cut, causing nutrient rich exudates and providing attachment sites for microbes. Consequently, fresh-cut produce is more susceptible to microbial proliferation than whole produce.


RESULTS
The aim of this study was to examine the impact of storage temperature on the growth and survival of Listeria monocytogenes and Salmonella enterica on a fresh-cut 'Conference' pear over an 8 day storage period. Pears were cut, dipped in antioxidant solution, artificially inoculated with L. monocytogenes and S. enterica, packed under modified atmospheric conditions simulating commercial applications and stored in properly refrigerated conditions (constant storage at 4 °C for 8 days) or in temperature abuse conditions (3 days at 4 °C plus 5 days at 8 °C). After 8 days of storage, both conditions resulted in a significant decrease of S. enterica populations on pear wedges. In contrast, when samples were stored at 4 °C for 8 days, L. monocytogenes populations increased 1.6 logarithmic units, whereas under the temperature abuse conditions, L. monocytogenes populations increased 2.2 logarithmic units.


CONCLUSIONS
Listeria monocytogenes was able to grow on fresh-cut pears processed under the conditions described here, despite low pH, refrigeration and use of modified atmosphere. © 2016 Society of Chemical Industry.
Food Technology Department, University of Lleida, XaRTA-Postharvest, Agrotecnio Center, Rovira Roure, 191, 25198, Lleida, Catalonia, Spain.
Pilar
P
Colás-Medà
Food Technology Department, University of Lleida, XaRTA-Postharvest, Agrotecnio Center, Rovira Roure, 191, 25198, Lleida, Catalonia, Spain.
Inmaculada
I
Viñas
Food Technology Department, University of Lleida, XaRTA-Postharvest, Agrotecnio Center, Rovira Roure, 191, 25198, Lleida, Catalonia, Spain.
Isabel
I
Alegre
IRTA, XaRTA-Postharvest, Edifici Fruitcentre, Parc Científic i Tecnològic Agroalimentari de Lleida, Parc de Gardeny, 25003, Lleida, Catalonia, Spain.
Maribel
M
Abadias
D005506:Food Contamination / Q000517:prevention & control; D005511:Food Handling / Q000379:methods*; D005519:Food Preservation; D061353:Food Storage; D005638:Fruit / Q000737:chemistry* / Q000382:microbiology; D008089:Listeria monocytogenes / Q000254:growth & development*; D050296:Microbial Viability; D031989:Pyrus / Q000737:chemistry / Q000382:microbiology*; D012034:Refrigeration; D019779:Salmonella enterica / Q000254:growth & development*
cold; foodborne pathogen; fruit; ready-to-eat