  We study the impact of the fermion vacuum term in the SU(3) quark meson model
on the equation of state and determine the vacuum parameters for various sigma
meson masses. We examine its influence on the equation of state and on the
resulting mass radius relations for compact stars. The tidal deformability
$\Lambda$ of the stars is studied and compared to the results of the mean field
approximation. Parameter sets which fulfill the tidal deformability bounds of
GW170817 together with the observed two solar mass limit turn out to be
restricted to a quite small parameter range in the mean field approximation.
The extended version of the model does not yield solutions fulfilling both
constraints. Furthermore, no first order chiral phase transition is found in
the extended version of the model, not allowing for the twin star solutions
found in the mean field approximation.
