Temporal pattern of microbial indicators of ready-to-eat rocket salads during shelf life.
BACKGROUND
From 2001-2009 there have been numerous community alerts and notifications about the rocket salad produced in Italy and distributed in Europe. Our study describes the evolution of the microbial quality of ready to eat rocket salad during shelf life among three different Italian producers.


METHODS
Total Mesophilic Count (TMC) and Escherichia coli (EC) count were measured in 248 samples. We used Wilcoxon test to compare the median values of TMC and EC counts and Kruskal Wallis test to compare the producers.


RESULTS
The TMC and EC values differed among producers at the stages of raw material and in the finished product (Kruskall Wallis test, p < 0.05). The evolution of bacterial charges had significant differences among producers at expiration date (Wilcoxon test, p < 0.05). More than half of the samples (54.8%) exceed reference standard for TMC after 48 h from packaging.


CONCLUSIONS
Differences among producers may linked to the different minimal processing technologies adopted after harvesting.
Dipartimento di Sanità Pubblica e Malattie Infettive, Sapienza Università di Roma, Rome, Italy. E-mail: maria.degiusti@uniroma1.it.
Maria
M
De Giusti
Angelo G
AG
Solimini
Alessia
A
Cottarelli
Corrado
C
De Vito
Caterina
C
Aurigemma
Daniela
D
Tufi
Ludovico
L
Piccinato
Antonio
A
Boccia
Lucia
L
Marinelli
D058491:Bacterial Load; D015169:Colony Count, Microbial; D005506:Food Contamination; D005516:Food Microbiology / Q000379:methods*; D007558:Italy; D014675:Vegetables / Q000382:microbiology