Development of Kimpul Starch-Based Composite Films Reinforced with TEMPO-Oxidized Cellulose Microfiber for Food Packaging

This study investigated the development of starch-based films reinforced with TEMPO-oxidized cellulose microfibrils (TOCMF) using kimpul starch as the primary polymer matrix. A Box Behnken Design (BBD) combined with Response Surface Methodology (RSM) was employed to evaluate the effects of starch, TOCMF, and glycerol contents on the mechanical properties (tensile strength (TS) and elongation at break (EAB)). The quadratic models were statistically significant with high coefficients of determination (R2 = 0.86–0.98) and non-significant lack-of-fit, confirming their adequacy for prediction and optimization. The optimized film formulation achieved superior mechanical properties, with TS (38.78 MPa) higher than most previously reported starch-based films, while maintaining desirable flexibility (EAB = 18.59%). This work highlights the potential of underutilized kimpul starch incorporated with TOCMF to develop packaging films with superior functional performance, providing new insights into the design of sustainable materials for food packaging applications. Moreover, the use of kimpul, a low-cost and locally abundant tuber, offers an additional advantage by promoting value-added utilization of indigenous resources for environmentally friendly packaging.