  Protoneutron stars are hot and lepton rich objects formed as a result of type
II supernovae explosion. This paper describes results of analysis of
protoneutron star models constructed under the assumptions that strange
particles are present in the core. All calculations have been performed for the
neutrino opaque matter when the entropy per baryon is of the order 2. The
equation of state which is crucial for the structure and composition of a star
has been obtained in the framework of the chiral SU(3) model and compared with
the one involving derivative coupling of baryons to mesons. Of special interest
in this paper is the comparison of the two protoneutron star models with those
formed when neutrinos leak out of the system, described as cool, deleptonized
neutron stars. It has been shown that the maximum mass of the hot protoneutron
star with trapped neutrinos is close to 1.9 M (the Sun Mass) in case of the
SU(3) model. However, deleptonization reduces the value of stable protoneutron
star mass significantly to 1.5 M.
