The reason why stewed ribs change their taste because of vacuum is that vacuum packaging will eliminate oxygen in food, which will lead to changes in chemical reactions inside food, thus affecting its taste and texture.

Pork ribs are not completely cooked in the stewing process, or are not properly handled in the vacuum packaging process, which will cause bacteria to multiply, lead to food spoilage, and then affect its taste.

After vacuumizing, oxygen can be isolated, and food spoilage can be delayed under certain circumstances. However, many microorganisms, such as bacteria and viruses, can survive in an oxygen-free environment, and the living environment of microorganisms is also closely related to temperature, so sterilization is needed after vacuumizing.