Prepare two 9x5 loaf pans with parchment paper or with cooking spray and dusting with flour.
Preheat oven to 350.
Zest 2 oranges and set zest aside. Juice oranges and the grapefruit. Collect enough juice to measure 1-1/2 cups. Add water if you don't have enough juice.
Heat juice over medium heat until steaming then remove from heat and stir in sugar until dissolved. Then stir in canola oil.
In a large bowl mix together flours, baking powder, baking soda and salt. Stir in zest and berries. Then stir in orange juice mixture into dry ingredients until just combined.
Evenly divide batter between the two loaf pans. Place in the oven on a middle rack and bake until crust is golden brown and crisp. About 45-50 minutes or until a tooth pick inserted into the centre comes out clean.
Let cool in pan on a wire rack for 10 minutes, then remove from the pan and let cool completely
Slighlty adapted from 350 best vegan recipes by Deb Roussou