The mean numbers of Salmonella inoculated onto agar-filled eggs
were 4.76±0.17 (SD) log10 CFU/egg for control and test eggs coated
with 1% chitosan, and 3.77±0.32 (SD) log10 CFU/egg for control and
test eggs coated with 2% chitosan. There was no significant difference
(pN0.05) between the initial numbers on coated eggs and the
corresponding control eggs. The initial rate of shell penetration was
S. Leleu et al. / International Journal of Food Microbiology 145 (2011) 43–48 45
not affected by the presence of a chitosan coating. For both coated and
uncoated eggs, most shells were penetrated after 4 days of storage
(Table 3). In Experiments 1 and 2, most eggshells that were
penetrated had been penetrated by day 14 or 10 of storage,
respectively. At the end of storage, there was no significant difference
(pN0.05) in the percentage of penetrated eggs in the 1% chitosan
coated egg and the control groups. However a significantly smaller
(pb0.05) percentage of the eggs was penetrated in the 2% chitosan
coated group of eggs than in the control group (Table 3).
3.4. Influence of Salmonella shell contamination on trans-shell penetration
At the end of storage, the numbers of Salmonella on all agar-filled eggs
were determined (Fig. 2). The numbers of Salmonella on eggshells were
significantly higher (pb0.05) for eggshells that were penetrated
compared to those that were not