The changes in mesophilic bacteria count on coated and uncoated
apples stored in different conditions are presented in Fig. 6. The initial
bacterial count was in the range from 3.15 to 3.78 log CFU/g. It was
observed during apple storage at 16 °C that pullulan coating with SBE
effectively inhibited mesophilic bacteria growth, whose count at the
end of storage period was reduced by nearly 1 logarithmic cycle. The
numbers of mesophilic bacteria on the control apples and those coated
with pullulan coating did not decrease. At a refrigeration temperature of
2 °C, the number of mesophilic bacteria was lowered by 1 logarithmic
cycle on the apples coated with P + SBE coating just during the first
10 days of their storage and after that it was not subject to any significant
changes. In turn, the number of mesophilic bacteria on uncoated
apples and those coated with pullulan coating without SBE decreased
insignificantly after 20 days of storage. Despite the statistically significant
(P b 0.05) reduction in the number of mesophyll on apples coated
with P + SBE compared to uncoated (control) apples, this coating was
found to offer low antibacterial protection. This phenomenon could
result from the large dispersion of antibacterial compounds contained
in plant extracts of the coating, and thus less exposure to bacterial
cells, as pointed out by Ponce, Roura, del Valle, and Moreira (2008). In
view of these authors, non-volatile antibacterial compounds derived
from plant extracts may selectively and gradually migrate from the