Exhausting is a crucial step in the canning process that involves removing air from the head space of the can before sealing to create a partial vacuum. This usually results in a vacuum degree of 250-450mmHg column in the can. The primary purpose of exhausting is to prevent the development and growth of aerobic bacteria and molds, as well as reduce container deformation or damage due to air expansion during sterilization. Exhausting controls or reduces the corrosion of the inner wall of the can during food storage, and avoids the change of food color, aroma, and taste while preserving vitamins and other nutrients. The three common methods of exhausting include thermal exhaust using heat to remove air from the can, vacuum sealing, and steam sealing, where steam is sprayed into the head gap of the can during sealing. With these effective methods, exhausting plays a crucial role in ensuring the safety and quality of canned food.