Design and characterization of a pea protein/nucleic acid-based biopolymeric film for strawberry preservation

The escalating environmental issues related to petroleum-derived plastics have prompted a shift toward sustainable food packaging materials. However, current sustainable alternatives lack adequate barrier and mechanical properties. The use of nanomaterials can present a promising solution to surmount these challenges. This study aimed to develop innovative and eco-friendly film systems formulated with pea protein and deoxyribonucleic acid (DNA) nanoparticles. Control (PF) was designed using pea protein alone. PDF1, PDF2, PDF3, and PDF4 contained both protein and DNA, with nanoparticle quantities of 0.01, 0.1, 0.5, and 1.0 (g/5 g), respectively. Molecular characterization revealed the presence of molecular groups associated with polypeptide chains and nucleic acids, along with their interactions. A high DNA nanoparticle concentration in the film system prevented the formation of an organized structure. Amount of DNA nanoparticles led to slight differences in thickness whereas moisture content (PF: 23.70 %, PDF1: 19.30 %, PDF2: 11.36 %, PDF3: 14.87 %, and PDF4: 15.81 %) decreased compared with the control. Moreover, incorporation of DNA nanoparticles increased the opacity from 1.46 to 4.14 Abs600/mm. PDF2 was ahead in terms of oxygen barrier characteristics. A similar improvement was also observed in water transmission index (WTI) (PDF2: 10.89 %, PDF3: 15.29 %, PDF4: 17.55 %, PDF1: 27.46 %, and PF: 30.89 %). The combination of pea protein with DNA led to a decrease (9.68-6.07 MPa) in tensile strength and an increase (119.49-146.29 %) in elongation at break. PDF2 maintained strawberry quality over 14 days of storage compared to other film systems by reducing weight loss, preserving biochemical properties, and managing microbial load.