Testing Barrier Properties in Cereal Packaging

The satisfying crunch of a morning cereal relies on more than just the recipe. Behind the scenes, a carefully engineered packaging system works tirelessly to maintain freshness and prevent spoilage. At the heart of this system lie the plastic and metallized films that form the inner bag, acting as silent guardians against the elements. But how do manufacturers ensure these films are up to the task? The answer lies in rigorous barrier property testing.

Cereal is vulnerable to two primary threats: moisture and oxygen. Moisture leads to sogginess and clumping, while oxygen triggers oxidation, resulting in staleness and off-flavors. To combat these threats, packaging films must possess excellent barrier properties, effectively blocking the passage of water vapor and oxygen.

Two critical tests, Water Vapor Transmission Rate (WVTR) and Oxygen Transmission Rate (OTR), are used to evaluate these barrier properties. Water Vapor Transmission Rate (WVTR) testing is crucial for ensuring cereal packaging effectively prevents moisture ingress. This test measures the amount of water vapor that passes through a film over a specific time period, under controlled temperature and humidity. By placing a dry desiccant on one side of the film and a humid environment on the other, the weight gained by the desiccant over time is used to calculate the WVTR. A lower WVTR value signifies a superior moisture barrier, indicating the film's ability to maintain the cereal's dryness and crunchiness.

Oxygen Transmission Rate (OTR) testing is equally vital for preserving cereal freshness. This test quantifies the amount of oxygen that permeates a film over a defined time, under controlled conditions. Placing the film between two chambers, one with a known oxygen concentration and the other oxygen-free, allows for the measurement of oxygen increase in the oxygen-free chamber, which is then used to calculate OTR. A lower OTR value denotes a better oxygen barrier, signifying the film's effectiveness in preventing oxidation and maintaining the cereal's desired freshness.

These tests require precise instrumentation and controlled environments to ensure accurate and reliable results. Factors such as temperature, humidity, and the thickness of the film can significantly impact barrier properties.

Labthink C403H 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.

While WVTR and OTR values provide valuable data, it's important to consider other factors that can affect barrier performance, such as seal integrity, puncture resistance, and impact resistance are essential to ensure product protection during transportation and storage.

As consumer demand for high-quality, longer-lasting food products grows, the development of innovative packaging solutions becomes increasingly critical. By investing in rigorous testing and analysis, the food industry can optimize packaging design, extend product shelf life, and ultimately deliver superior products to consumers.