As a method of food processing and preservation, smoking has existed since ancient times. Smoked food is called smoked food. This kind of food mainly includes animal food, such as meat products, poultry products and fish products. Most western meat products, such as enema, ham and bacon, are smoked. Many traditional meat products in China, such as Hunan-style and Sichuan-style bacon and Goubangzi smoked chicken, have also been smoked. Some plant foods can also be treated by smoking, such as bean products (smoked dry) and dried fruits (dates).