What type of packaging replaces air in a sealed packet with another gas to prevent bacteria growth?

Modified atmosphere packaging is correct because it involves altering the composition of gases surrounding the food within the sealed packet. By replacing oxygen, which can support the growth of aerobic bacteria, with gases such as carbon dioxide or nitrogen, the growth of bacteria is inhibited, thereby extending the shelf life of the food. This technique is commonly used for a variety of perishable products, including meats and fruits, to maintain their freshness and prevent spoilage.

In contrast, vacuum packaging removes air entirely from the package, which also helps in preventing bacteria growth but does not involve replacing the air with a different gas — it eliminates it. Sealed packaging simply refers to the process of enclosing food in a package, which might not necessarily alter the atmosphere for improved preservation. Active packaging typically involves incorporating substances into the packaging material that can interact with the food or the environment (like moisture absorbers or oxygen scavengers) but does not specifically involve replacing gases.