Evaluating the Barrier Performance of Protein-Based Films

Protein-based films, derived from sources like whey, soy, and gelatin, are emerging as promising sustainable alternatives to traditional petroleum-based plastics. Their biodegradability, edibility (in some cases), and potential for tailored functionalities make them attractive for various applications, particularly in food packaging and biomedicine. These films must undergo rigorous testing to ensure they effectively perform their intended roles. A crucial aspect of this evaluation lies in assessing their barrier properties.

Protein films are designed to fulfill diverse functionalities. In food packaging, they aim to extend shelf life by preventing moisture loss, oxidation, and microbial growth. In biomedical applications, they might serve as drug delivery systems or wound dressings, requiring biocompatibility and controlled release capabilities. These functionalities depend heavily on the film's ability to act as a barrier against various substances.

Barrier properties refer to a film's ability to impede the passage of different molecules. Essential barrier tests include evaluating water vapor permeability (WVP), oxygen permeability (OP), and sometimes permeability to other gases and aromas. WVP measures the rate at which water vapor travels through the film. This is vital for maintaining the desired moisture content of packaged goods. The gravimetric method, a common WVP test, involves measuring the weight gain of a desiccant placed beneath the film in a controlled humidity environment. Lower WVP values indicate a better moisture barrier, crucial for preventing soggy snacks or dried-out produce.

OP, on the other hand, measures the rate of oxygen transmission. This is critical for preventing oxidative degradation of food, which leads to rancidity and off-flavors. Coulometric or manometric methods are employed to quantify OP, with lower values indicating a more effective oxygen barrier. Beyond these, permeability to other gases like carbon dioxide (important for modified atmosphere packaging) and nitrogen, as well as aroma compounds, may also be assessed using gas chromatography or sensory evaluation.

Labthink C360H Water Vapor Transmission Rate Test System, is designed and manufactured based on the gravimetric determination method and conforms to the requirements of ASTM E96. This instrument can be used to measure the water vapor transmission rate of barrier materials with high, medium and lower moisture barrier properties with a wide testing range and high testing efficiency. The instrument features Labthink’s patented test chamber design with multiple test dishes. C360H is equipped with precision made test dishes, highly accurate balance, embedded professional software which supports automatic controlling of temperature, humidity and flow rate precisely and guarantees the testing sensitivity and repeatability of the test results. C360H is applicable to determination of water vapor permeability of plastic films, sheeting, paper, packages and other packaging materials in food, pharmaceutical, medical apparatus and building materials.

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.

These tests are significant because they directly correlate with the film's performance in real-world applications. A high WVP in a food package could lead to spoilage, while a high OP could compromise the quality and safety of oxygen-sensitive products. By rigorously testing these barrier properties, researchers and manufacturers can optimize protein-based film formulations and processing methods to create effective, sustainable packaging and biomedical solutions.

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