  Within the chiral soliton model the SU(3) breaking collective hamiltonian
introduces representation mixing in the baryonic wave functions. We calculate
${\cal{O}}(m_s)$ effects of this mixing on the decay widths of decuplet and
antidecuplet baryons. We find importance of the 27-plet admixture in the
$\Theta^+$ and $\Xi_{\bar{10}}$ decays. The role of the $1/N_c$ nonleading
terms in ${\cal{O}}(m_s)$ transition matrix elements is discussed.
