Phosphorescence is a form of luminescence that persists after the source of excitation has been removed, as stored energy is released gradually as light. It differs from fluorescence, which ceases almost immediately when excitation stops. In food science, luminescence phenomena are exploited in analytical techniques: phosphorescent and fluorescent markers help detect contaminants, verify the uniformity of coatings, and study the behavior of packaging materials. Although phosphorescence itself is not a food property of commercial interest, understanding it supports the correct use of light-based inspection and analytical instruments. In quality control, luminescence-based methods offer rapid, sensitive, non-destructive options for certain testing applications.