  We analyse Raman-induced self-frequency shift in two-component solitons
supported by both quadratic and cubic nonlinearities. Treating Raman terms as a
perturbation, we derive expressions for soliton velocity and frequency shifts
of the fundamental frequency and second harmonic soliton components. We find
these predictions compare well with simulations of soliton propagation. We also
show that Raman shift can cause two-component solitons to approach the boundary
of their own existence and subsequently trigger soliton instabilities. In some
cases these instabilities are accompanied by an almost complete transfer of
power to the second harmonic, and emergence of a single-component Kerr
solitonic pulse.
