How does a hermetic seal protect canned fruit from spoilage?

In the context of fruit processing, a hermetic seal is essential for preventing food spoilage by acting as a physical barrier that keeps external microorganisms from entering the container after the sterilization process.1

During canning, fruit is typically heated to destroy spoilage-causing organisms and inactivate enzymes that lead to browning or softening. The hermetic seal is created by rolling and flattening the cover and body flange of the container, often with the aid of a polymer sealing compound dispersed between the metal layers.21

By maintaining this airtight seal, the process ensures that no new bacteria, molds, or yeasts can contaminate the contents once the initial heat treatment has rendered the food sterile. This combination of thermal destruction and the prevention of recontamination is the fundamental principle that allows canned fruit to remain preserved until the container is opened.1