Leather food. According to the doctor's website, jelly belongs to the category of leather food, and the food category is in the food label, which is the name marked by the state. Frozen skin is a traditional food, which belongs to fresh, tender and slippery braised dishes. The main raw materials of skin jelly are pigskin, bones and seasonings, and the main edible parts are pigskin, bone marrow and fat, which are rich in nutrition.