Bionanocomposite films with plasticized WPI-jujube polysaccharide/starch nanocrystal blends for packaging fresh-cut carrots

Abstract

New nanocomposite films with whey protein isolate (WPI, 5–10%), purified jujube polysaccharide (JPS, 5–15%) with a molecular weight of 1.35 × 105 Da, and ∼67.5 nm spherical-like starch nanocrystal (SNC, 0.32–3.68%) were optimally developed. The use of 10.0% WPI, 12.72% JPS, and 1.31% SNC resulted in the best physical (i.e., thickness: 0.15 mm, density: 0.86 g/cm3, contact angle: 66.9°, moisture content: 21.06%, water solubility: 41.68%, and moisture absorption: 77.56%), and mechanical (i.e., tensile strength: 14.0 MPa, elongation at break: 14.87%, and elastic modulus: 47.80 MPa) properties. Scanning electron (SEM) and atomic force (AFM) microscopies images proved that the SNC ensures the development of a more continuous and homogeneous surface with lower roughness. The optimal bionanocomposites with favorable water-vapor (0.63 ×10-10 g/m s Pa) and oxygen (9.62 cm3/m2 d atm) permeability better maintained the physicochemical, sensory, and microbiological properties of fresh-cut carrots than polyvinyl chloride (PVC) film during the cold storage.