  This work is a follow-up of our recent observation that in the SU(3) flavor
limit with vanishing current quark masses the temperature for the chiral
transition is substantially reduced by adding eight-quark interactions to the
Nambu - Jona-Lasinio Lagrangian with U_A(1) breaking. Here we generalize the
case to realistic light and strange quark masses and confirm our prior result.
Additionally, we demonstrate that depending on the strength of OZI violating
eight-quark interactions, the system undergoes either a rapid crossover or a
first order phase transition. The meson mass spectra of the low lying
pseudoscalars and scalars at T=0 are not sensitive to the difference in the
parameter settings that correspond to these two alternatives, except for the
singlet-octet mixing scalar channels, mainly the sigma meson.
