  The distortions in the thermal energy spectra for neutrinos produced in a
supernova when a resonant oscillation, MSW effect, occurs are determined. In
order to show this effect for some relevant and representative examples of
unified gauge models, we have chosen $SO(10)$, and $SU(5)_{SUSY}$,
$SO(10)_{SUSY}$ with a particular scheme for fermion masses (DHR model). The
analysis has been performed for two choices of neutrinos parameters, predicted
by the above models, and capable to explain the solar neutrino problem. In both
cases one observes a strong distortion in the electron neutrino energy
spectrum. This effect, computed for a wide range of $SO(10)_{SUSY}$ models has
produced the same results of the previous supersymmetric ones.
