Impact of adding dietary fibers and maltodextrin on the mechanical, morphological, optical, barrier and thermal properties of potato starch-based edible films

Abstract

The incorporation of prebiotic dietary fibers and maltodextrin into potato starch-based composite films was investigated to evaluate their effects on optical, mechanical, structural, barrier, and thermal properties. The dietary fibers studied included β-glucan, citrus pectin, and chicory inulin with different degrees of polymerization (DP): inulin DP 10 (DP ≥ 10) and inulin DP 23 (DP ≥ 23). For comparison, films were also formulated with maltodextrin and a control containing only potato starch. The results revealed that β-glucan and citrus pectin significantly enhanced the tensile strength (up to 38.53 MPa) and Young's modulus (15.72 ± 2.84 MPa for β-glucan, 12.80 ± 1.68 MPa for citrus pectin), indicating increased rigidity. In contrast, maltodextrin improved film flexibility, as evidenced by the highest elongation at break (12.32 ± 3.33 %) and the lowest Young's modulus (8.76 ± 2.14 MPa). X-ray diffraction showed that β-glucan increased crystallinity, whereas citrus pectin reduced crystallinity, improving compatibility with starch. Films containing inulin, particularly DP ≥ 10, exhibited the highest water solubility (35.72 ± 2.83 %), making them promising candidates for fast-dissolving applications. Thermal analysis revealed that all composite films exhibited higher thermal stability than the control, with maximum decomposition temperatures ranging from 318 °C to 327 °C, compared to 314 °C for the starch-only film. These findings underscore the potential of dietary fiber-enriched edible films for food packaging and functional delivery systems, where enhanced mechanical properties, controlled solubility, and improved thermal stability are desirable.