Testing Gas Exchange in Fresh Food Packaging

Preserving the freshness of fruits and vegetables is a continuous struggle against moisture loss, oxygen exposure, and other environmental influences. This research delves into finding the ideal packaging solution for a wide variety of produce, focusing on three commonly used films: low-density polyethylene (LDPE), polypropylene (PP), and polyvinyl chloride (PVC).

The researchers employed a scientific approach to evaluate the effectiveness of these films. Specialized instruments measured the Oxygen Transmission Rate (OTR), Carbon Dioxide Transmission Rate (CTR), and Water Vapor Transmission Rate (WVTR) of each film. These instruments assess how readily the film allows crucial gases and moisture vapor to pass through. Ideally, the packaging should enable produce to "breathe" at a controlled rate, minimizing both oxygen exposure and excessive moisture loss.

The produce samples were stored in each film type at two temperatures (5°C and 10°C). After the storage period, researchers analyzed storage life, peel color, and flesh firmness. These factors significantly impact the quality and marketability of the produce.

The tests revealed that PVC films, particularly PVC 40 (40 micrometers thick), came closest to matching the ideal gas exchange rates (OTR and CTR) required by many fruits and vegetables. However, all tested films exhibited lower WVTR than desired. This suggests that while PVC 40 might optimize gas exchange, it might also lead to in-package condensation due to insufficient moisture release.

C406H Oxygen /Water Vapor Transmission Rate Test System is based on the testing principle of Coulometric oxygen sensor and infrared water vapor sensor. It is designed and manufactured according to ASTM D3985、ASTM F1249，ISO 15106-2 and other relevant standards to provide high precision and high efficiency oxygen and water vapor transmission rate tests for high and medium gas barrier materials. It is suitable for testing the oxygen and water vapor transmission performance of films, sheets and related materials in the fields of food, medicine, medical devices, daily chemicals, photovoltaic, electronic and many others.

The benefits of these tests are extensive. Identifying the film offering the closest gas exchange rates (PVC 40) provides a strong foundation for developing modified atmosphere packaging (MAP) for various fruits and vegetables. Furthermore, the storage life analysis demonstrates the effectiveness of PVC 40 in extending shelf life (up to 25 days at 5°C). Finally, the evaluation of peel color and firmness offers valuable insights into produce quality during storage.

The study acknowledges the need for further refinement. The identified PVC film might require the incorporation of a moisture scrubber to manage condensation. This research paves the way for optimizing packaging for a wide variety of produce, leading to extended shelf life and reduced food waste.

As the demand for functional packaging materials grows, testing methods are evolving to ensure a more comprehensive evaluation of packaging films. Labthink encourages collaboration with packaging industry companies for quality control! Visit the website www.labthink.com to learn more!