Preheat oven to 350F. In a medium mixing bowl, whisk together oil, milk, orange zest and orange juice concentrate. Set aside. Sift together cake flour, salt and baking powder into a bowl. Set aside.
In the bowl of an electric mixer, whisk together eggs and sugar on high until doubled in volume and pale. Replace the whisk attachment with the paddle and add wet ingredients to mixer. Beat on low until incorporated. Gradually add dry ingredients to the mixer and beat on low until incorporated. Fold in pine nuts and orange segments. Lightly oil a 12-inch round baking pan. Pour batter into pan. Bake 35-40 minutes.