Harvest & Post-Harvest
Packaging: Moisture, Gas & Light Barriers
Packages differ in water-vapor transmission, oxygen transmission, light protection, seal quality, headspace, and mechanical protection. Packaging should be chosen for the product state and storage objective rather than by material name alone.
Key concepts
- A moisture barrier slows exchange but cannot correct an improperly dried product
- Oxygen exposure can contribute to oxidation
- Transparent packages provide less light protection unless secondary packaging is used
- Seal integrity and repeated opening can dominate theoretical material performance
What to measure or observe
- Record package material and closure type
- Inspect seal integrity
- Track storage temperature and light exposure
- Record how often a package is opened and whether moisture changes afterward
Common mistakes
- Assuming all plastic or all glass performs identically
- Using barrier packaging as a substitute for drying
- Ignoring headspace and repeated opening
- Comparing packages without the same storage conditions
Visuals this lesson still needs
- Packaging barrier comparison
- Seal-leak diagram
- Headspace and opening cycle
- Light exposure comparison