What method can be used to preserve food by preventing oxygen from reaching it?

Vacuum sealing is an effective method for preserving food by removing air from the packaging, thereby preventing oxygen from reaching the food. Oxygen is a key factor in the growth of aerobic bacteria and mold, as well as in causing the food to oxidize, which can lead to spoilage. By using vacuum sealing, food can be kept fresher for longer periods because it minimizes the chances of these processes occurring.

In the context of the other methods listed, freezing can prevent spoilage but does not eliminate oxygen; it simply slows down the growth of microorganisms and the chemical reactions that lead to spoiling. Curing involves using chemicals like salt or sugar to inhibit microbial growth, but it does not specifically prevent oxygen exposure. Smoking adds flavor and can also provide some preservation benefits, but it does not effectively eliminate oxygen from contact with the food. Therefore, vacuum sealing stands out as the most direct method for minimizing oxygen exposure.