be spread during processing and thus further contaminate uncontaminated
products. In this sense, it is assumed that the potential for crosscontamination
is present if one (or more) units are contaminated. If
cross contamination occurs and no lethal or inactivation treatments
are applied afterward, sampling plans may become important tools
intended to detect the possible contamination (Jongenburger et al.,
2011a, 2011b), although their effectiveness will depend on the levels
of contamination and their distribution in the final product to be tested.
In this study apples were chosen as a model product for tree fruits for
investigating the potential for cross contamination and survival of an
enteric pathogen such as Salmonella spp. during industrial processing
and subsequent storage, respectively.
The aim of this work was i) to study the potential for cross contamination
of apples simulating industrial processing, ii) to assess the survival
Salmonella on the apples after a cross contamination event, and
iii) based on these data, to assess suitable sampling plans to detect
Salmonella in apples.
in apples, and only environmental samples showed contamination by Salmonella after processing including both
water and sponges. Experiments on the survival of Salmonella on apple showed that the pathogen was capable to
survive for 12 days, only showing a significant drop at the end of the experiment. Finally, two-class attribute
sampling plans were assessed as tool to detect Salmonella in different contamination scenarios in fresh apple.
This analysis indicated that with the highest inoculum level, a total of 16 apples would be needed to reach 95%
of detecting Salmonella (i.e. lot rejection). In turn, when low levels were assessed (5–6 log cfu/apple), a large
number of apples (n= 1021) would have to be sampled to obtain the same confidence level (95%). If the environment
is sampled (i.e. water and sponges), a lower number of samples would be needed to detect the pathogen.
However, the feasibility of environmental sampling has not been assessed from a practical point of view.
Overall, the results in this study evidenced that cross contamination by Salmonella might occur during processing
of fresh apples and subsequently, the pathogen might survive for a noticeable period of time.
© 2014 Elsevier B.V. All rights reserved.