The Nambu-Jona-Lasinio model for quarks has been extensively used as an effective description of Quantum Chromodynamics at low energies. Its extension, the Polyakov-NJL model incorporates a coupling of the Polyakov loop to dynamical quarks.
I will describe how to construct mesons and baryons from the elementary interactions provided by these models. Then, it is straightforward to compute the hadronic masses as a function of temperature and pin down the melting temperature at which hadrons are unstable against decay into quarks. The results show a clear evidence of a flavor dependence of the meson/baryon melting temperature. This idea has already been suggested by experimental results in heavy-ion collisions, and supported by recent lattice-QCD results for the freeze-out temperature.