The structure of strange dwarfs and that of hybrid stars with the same baryonic number is compared. There is a critical mass (M ≈ 0.24M⊙) in the strange dwarf branch, below which configurations with the same baryonic number in the hybrid star branch are more stable. If a transition occurs between both branches, the collapse releases an energy of about of 3 × 1050 erg , mostly in the form of neutrinos resulting from the conversion of hadronic matter onto strange quark matter. Only a fraction (~ 4%) is required to expel the outer neutron-rich layers. These events may contribute significantly to the chemical yield of nuclides with A ≥ 80 in the Galaxy, if their frequency is of about one per 1,500 years.