Eco-friendly rapeseed protein-chitosan hybrid nanocomposite films for active food packaging and preservation

Rapeseed proteins are an interesting bioresource for the growing bio-economy due to their numerous physiochemical properties, making them a renewable resource for food packaging applications. In this study, rapeseed protein-chitosan blends were compatibilized by montmorillonite (MMT) and citric acid to develop active food packaging films. Three blends were assessed for mechanical, thermal, water vapor permeability, opacity, water uptake, antioxidant activities, recyclability, and biodegradability. Response surface methodology (RSM) was used to optimize the effects of reinforcement, cross-linking, and pH on the film's tensile strength. The predicted optimal ratios were 3.40%, 5% (w/w), at a pH of 5, resulting in a tensile strength of 26.86 MPa and 40% elongation at break. The study revealed that dual compatibilization with MMT and citric acid enhanced compatibility, barrier properties, water stability, light resistance, and thermal stability. Furthermore, active packaging films were tested by preserving the quality of berries for 9 days at room temperature, showing it maintained fruit quality and extended shelf life. This study demonstrates a sustainable, efficient method for creating bioplastic films with high strength, durability, and excellent properties suitable for food preservation. • Hybrid films were developed from rapeseed protein, chitosan, MMT and citric acid. • RSM optimized MMT, citric acid to improve the mechanical strength of the films. • The films showed excellent thermal, mechanical, barrier and antioxidant properties. • Developed films preserved blueberries better by reducing decay and weight loss. • Films are biodegradable, recyclable and ideal for active food packaging.