  We examine the sensitivity of neutrino emissions to stellar evolution models
for a 15$M_\odot$ progenitor, paying particular attention to a phase prior to
the collapse. We demonstrate that the number luminosities in both electron-type
neutrinos ($\nu_e$) and their anti-partners ($\bar{\nu}_e$) differ by more than
an order of magnitude by changing spatial resolutions and nuclear network sizes
on stellar evolution models. We also develop a phenomenological model to
capture the essential trend of the diversity, in which neutrino luminosities
are expressed as a function of central density, temperature and electron
fraction. In the analysis, we show that neutrino luminosity can be well
characterized by these central quantities. This analysis also reveals that the
most influential quantity to the time evolution of $\nu_e$ luminosity is matter
density, while it is temperature for $\bar{\nu}_e$. These qualitative trends
will be useful and applicable to constrain the physical state of progenitors at
the final stages of stellar evolution from future neutrino observations,
although more detailed systematic studies including various mass progenitors
are required to assess the applicability.
