We propose a new model for describing baryon semileptonic decays for estimating $F$ and $D$ values with explicit breaking effects of both SU(3) and SU(2) flavor symmetry, where all possible SU(3) and SU(2) breaking effects are induced from an effective interaction. An overall fit including the weak magnetism form factor yields $F=0.477\ifmmode\pm\else\textpm\fi{}0.001$, $D=0.835\ifmmode\pm\else\textpm\fi{}0.001$, ${V}_{ud}=0.975\ifmmode\pm\else\textpm\fi{}0.002$, and ${V}_{us}=0.221\ifmmode\pm\else\textpm\fi{}0.002$ with ${\ensuremath{\chi}}^{2}=4.43/5\text{ }\text{ }\mathrm{d}.\mathrm{o}.\mathrm{f}.$. The spin content of strange quarks $\ensuremath{\Delta}s$ is estimated from the obtained values $F$ and $D$, and the nucleon spin problem is reexamined. Furthermore, the unmeasured values of $({g}_{1}/{f}_{1})$ and $({g}_{1})$ for other hyperon semileptonic decays are predicted from this new formula.