  Neutrinos coming from the Sun's core are now measured with a high precision,
and fundamental neutrino oscillations parameters are determined with a good
accuracy. In this work, we estimate the impact that a new neutrino physics
model, the so-called generalized Mikheyev-Smirnov-Wolfenstein (MSW) oscillation
mechanism, has on the shape of some of leading solar neutrino spectra, some of
which will be partially tested by the next generation of solar neutrino
experiments. In these calculations, we use a high-precision standard solar
model in good agreement with helioseismology data. We found that the neutrino
spectra of the different solar nuclear reactions of the proton-proton chains
and carbon-nitrogen-oxygen cycle have quite distinct sensitivities to the new
neutrino physics. The $HeP$ and $^8B$ neutrino spectra are the ones for which
their shapes are more affected when neutrinos interact with quarks in addition
to electrons. The shape of the $^{15}O$ and $^{17}F$ neutrino spectra are also
modified, although in these cases the impact is much smaller. Finally, the
impact in the shape of the $PP$ and $^{13}N$ neutrino spectra is practically
negligible.
