Development and Optimisation of Starch–Canola Fines Composite Films

The growing demand for biodegradable alternatives to conventional petroleum-based plastics has intensified interest in developing sustainable packaging materials from agricultural by-products [1-3]. This study investigated the dual valorisation of maize wet-milling spillage starch as a film-forming biopolymer matrix and canola fines, a lignocellulosic by-product of canola seed processing, as a functional filler for biodegradable film production. Starch-based composite films were prepared using varying concentrations of glycerol as a plasticiser and canola fines as reinforcement. Response Surface Methodology (RSM) was employed to evaluate and optimise the interactive effects of formulation variables on tensile strength, elongation at break, and water absorption.

The results demonstrated significant trade-offs between mechanical performance, flexibility, and moisture sensitivity. Increasing glycerol concentration reduced tensile strength while improving film ductility, whereas canola fines decreased water absorption and influenced elongation through interactions with glycerol. Although untreated canola fines provided limited tensile reinforcement, their incorporation contributed to improved moisture resistance and overall film functionality. Optimisation identified an optimal formulation containing 30.4% glycerol and 13.7% canola fines, achieving a balanced combination of properties, including a tensile strength of 3.3 MPa, elongation at break of 52.1%, and water absorption of 65.2%. These findings demonstrate the technical feasibility of converting low-value agro-industrial residues into value-added biodegradable packaging materials.

References

Navasingh, R.J.H. 2023. Sustainable Bioplastics for Food Packaging Produced from Renewable Natural Sources. Polymers, 15(18): 3760. https://doi.org/10.3390/polym15183760

Atiwesh, G., Mikhael, A., Parrish, C.C., Banoub, J. & Le, T.A.T. 2021. Environmental impact of bioplastic use: A review. Heliyon, 7(9): e07918. https://doi.org/10.1016/j.heliyon.2021.e07918

Shafqat, A., Al-Zaqri, N., Tahir, A. & Alsalme, A. 2021. Synthesis and characterization of starch based bioplatics using varying plant-based ingredients, plasticizers and natural fillers. Saudi Journal of Biological Sciences, 28(3): 1739–1749. https://doi.org/10.1016/j.sjbs.2020.12.015