Effective Lagrangian approach to multi-quark interactions

In this workshop we have presented the results obtained in the three-flavour ($N_f=3$) Nambu--Jona-Lasinio model Lagrangian which includes all non-derivative vertices at NLO in the $1/N_c$ expansion of spin zero multi-quark interactions. In particular the role played by the explicit chiral symmetry breaking interactions has been discussed in comparison with previous model Lagrangians.