In a large bowl mix walnuts, flours, baking powder, salt, and orange zest. In another bowl beat egg, add milk, syrup and butter and beat until smooth. Add milk mixture to dry ingredients and stir quickly to combine. Do not over mix. Pour into a buttered and floured loaf pan and bake in preheated 350 F oven for about 40 - 45 minutes or until well risen and golden and toothpick inserted in center comes out clean. Cool in pan for about 3 minutes then turn out onto rack and cool completely.