Water Vapour Transport Properties of Cassava Starch/Poly(Vinyl Alcohol) Films via Experimental and Fickian Methods

Background and Objective: Water vapour permeability is a critical property of packaging materials as it has marked effect on both the shelf-life and quality of packaged food products. Therefore, a study of water vapour transport properties through these films, as well as an understanding of the sorption kinetics provide a better understanding of how to optimize the water barrier properties of the films. Materials and Methods: In this research, the water vapour transport properties including the permeability and sorption behaviour of cassava starch/poly(vinyl alcohol) (PVA) films were studied over a range of starch-PVA compositions (PVA, 0-60%). Two methods were used to determine the water vapour permeability namely the experimental cup method and the theoretical Fickian method obtained by multiplying the sorption and diffusion parameters. Results: It revealed that the incorporation of 60% PVA into starch film was found to markedly reduce the water vapour permeability by 25.3% (experimental method) and 46.2% (Fickian method). The values of water vapour permeability obtained from both methods were found as the same order of magnitude. Conclusion: The study concluded that starch/PVA films have potential for biodegradable packaging applications.