Preparation of Passion Fruit Peel Extract/Polydopamine/Hydroxypropylmethylcellulose Film and Its Application in Banana Preservation

ABSTRACT The objective of this study was to evaluate the feasibility of blending passion fruit peel extract (PFPE) with polydopamine (PDA) solution and hydroxypropylmethylcellulose (HPMC) to prepare the properties of PFPE/PDA/HPMC composite films for their application in fruit and vegetable packaging. PFPE was extracted by ultrasonic‐assisted extraction method, which is simple, easy to operate and has high extraction efficiency, PFPE and dopamine were subjected to PFPE/PDA solution preparation, which in turn led to the preparation of HPMC, PFPE/PDA/HPMC films at different concentrations (0%, 5%, 10%, 15% and 20%), and 10% PDA/HPMC and PFPE/HPMC films were prepared with PDA and PFPE solutions, respectively. The interactions between the components in the films were analysed by infrared spectroscopy and X‐ray diffractometer, and the colour, mechanical properties, barrier properties and antioxidant activity of the films were determined. The results showed that the addition of PFPE/PDA solution had a positive effect on the performance of the films. The tensile strength of the composite films was 8.21 MPa, the elongation at break was 85.02% and the water vapour transmission was 2.62 × 10 −14 g·mm/(cm 2 ·h·Pa) when the content of PFPE/PDA was 20% compared to that of HPMC films; the DPPH radical scavenging rate and hydroxyl radical scavenging rate of the films increased with the increase of PFPE/PDA concentration, and the DPPH radical scavenging rate of the film with 20% additive was 28.71% and the hydroxyl radical scavenging rate was 34.77%, which were much higher than that of the HPMC film. The simulated bananas were stored at room temperature together with the films and stored at 25°C and tested every day, and it was found that the bananas without packaging film began to show browning on the third day, while the film with 20% additive still did not show obvious browning on the fifth day, so the addition of PFPE/PDA could effectively delay the browning of bananas and prolong their shelf life. In summary, this study improves the use value of passion fruit peel waste and provides new effective packaging for fresh bananas, while it can also provide a new way for the development of degradable films from plant extracts.