Cream butter, shortening, granulated sugar and brown sugar together until light and fluffy. Beat in egg, lemon juice and lemon peel, mix well In a separate bowl, combine remaining ingredients. Stir in creamed mixture. Cover, refrigerate for 1 hour Remove from refrigerator and form into 2 10" rolls on waxed paper. Wrap tightly and refrigerate overnight. Preheat oven to 400F. Slice rolls into 1/4inch slices, and bake on ungreased cookie sheets for 8-10 minutes