Bioinspired starch nanofibrous films with tunable hydrophobicity and water adhesion via tannic acid-interfacial self-assembly for food packaging

To address the limitations in water resistance and functionality of existing starch-based food packaging materials, this study developed a new sustainable food packaging material—starch nanofibrous films (SNFs) enhanced with an acylated tannic acid (ATA) interfacial self-assembly coating. Inspired by the unique hydrophobicity and water adhesion properties of rose petals, which effectively control surface characteristics to maintain microenvironmental humidity during food processing and storage, this approach significantly enhanced the water resistance, stability, and mechanical strength of the material. Specifically, the obtained SNFs/ATA exhibited a maximum water contact angle of ∼ 134.1°, tensile strength of ∼ 0.86 MPa, and Young's modulus of ∼ 43.48 MPa. Moreover, SNFs/ATA showed excellent antibacterial and antioxidant properties, UV-blocking capabilities, and degradability, making it an environmentally friendly choice for food packaging. In practical food preservation applications, cherry tomatoes packaged with SNFs/ATA showed a significant extension of shelf life to 15 days, with a 62.5 % reduction in spoilage rate, a 25.4 % decrease in weight loss, and good quality including pulp firmness, pH, titratable acidity, and total soluble solids. This work demonstrates structurally regulated polyphenol assembly in the preparation of all-natural green biomimetic surface, creating new opportunities for the development of sustainable bio-based food packaging systems.