There are many ways to add eggs to flour. However, it is recommended to use flour and starch to improve it. Sometimes baking powder is added to make it brittle. Others are mixed with foamed egg whites to make the fried layer fluffy and crisp.
This is because the outer layer fried by flour (mainly low-gluten flour) is plump and thick, dark in color and tough, but not brittle enough. Starch fried crust is crisp, golden and shiny, suitable for soft frying. However, only starch is used, so the paste is thin and the toughness is insufficient, and the fried products are easy to soften. Therefore, the improvement effect is better by mixing flour and starch.