  We obtain the in-medium effective potential of the three-flavor
Polyakov-Quark-Meson model as a real function of real variables in the Polyakov
loop variable, to allow for the study of all possible minima of the model. At
finite quark chemical potential, the real and imaginary parts of the effective
potential, in terms of the Polyakov loop variables, are made apparent, showing
explicitly the fermion sign problem of the theory. The phase diagram and other
equilibrium observables, obtained from the real part of the effective
potential, are calculated in the mean-field approximation. The obtained results
are compared to those found with the so-called saddle-point approach. Our
procedure also allows the calculation of the surface tension between the
chirally broken and confined phase, and the chirally restored and deconfined
phase. The values of surface tension we find for low temperatures are very
close to the ones recently found for two-flavor chiral models. Some
consequences of our results for the early Universe, for heavy-ion collisions,
and for proto-neutron stars are briefly discussed.
