  Complementary to high-energy experimental efforts, indirect astrophysical
searches of particles beyond the standard model have long been pursued. The
present article follows the latter approach and considers, for the first time,
the self-consistent treatment of the energy losses from dark flavored particles
produced in the decay of hyperons during a core-collapse supernova (CCSN). To
this end, general relativistic supernova simulations in spherical symmetry are
performed, featuring six-species Boltzmann neutrino transport, and covering the
long-term evolution of the nascent remnant proto-neutron star (PNS)
deleptonization for several tens of seconds. A well-calibrated hyperon equation
of state (EOS) is therefore implemented into the supernova simulations and
tested against the corresponding nucleonic model. It is found that supernova
observables, such as the neutrino signal, are robustly insensitive to the
appearance of hyperons for the simulation times considered in the present
study. The presence of hyperons enables an additional channel for the
appearance of dark sector particles, which is considered at the level of the
$\Lambda$ hyperon decay. Assuming massless particles that escape the PNS after
being produced, these channels expedite the deleptonizing PNS and the cooling
behaviour. This, in turn, shortens the neutrino emission timescale. The present
study confirms the previously estimated upper limits on the corresponding
branching ratios for low and high mass PNS, by effectively reducing the
neutrino emission timescale by a factor of two. This is consistent with the
classical argument deduced from the neutrino detection associated with SN1987A.
