  We use a proper-time regularization to define the one-loop fermion
determinant for the case in which explicit chiral symmetry breaking takes
place. We show how to obtain the polynomial by which the standard definition of
lndetD needs to be modified in order to arrive at the fermion determinant whose
transformation properties are consistent with the general symmetry requirements
of the basic Lagrangian. As an example it is shown how the fundamental
symmetries and the explicit chiral symmetry breaking pattern associated with
the ENJL model are preserved in a consistent way.
