Roll each puff pastry plate to a rectangle about 30 cm long. Cut into long strips about 2.5 cm thick.
From pastry paper, cut triangles, from which to roll the bag. These are future nozzles for tubules.
Wrap each strip around its duct, starting from the narrow end of the duct, the strips should overlap each other. Put on a baking sheet.
Grease with a beaten egg. Bake in a preheated oven to 180 degrees for 25 minutes.
Prepare a protein cream. To do this, bring the water with sugar to a boil. Beat whites with a pinch of citric acid until a firm foam. Pour syrup into the proteins at a high speed mixer. Beat until the protein mass has cooled.
Transfer the protein cream into a pastry bag and fill them with straws. Sprinkle with powdered sugar.