Preheat oven to 350 degrees.
Beat the melted butter, sugar, eggs, vanilla extract, lemon juice, white bean puree and lemon zest together until combined. In a separate bowl, combine the flours, baking powder and salt.
Stir the flour mixture into the egg mixture alternating with the buttermilk, starting and ending with the flour mixture.
In a separate bowl, toss the blueberries with 1 tablespoon of flour, fold into the batter. Pour the batter into prepared loaf pan.
Bake for 50-55 minutes, until a toothpick inserted into the center comes out clean. Cool bread in loaf pan on wire rack for one hour.