Optimization of Biodegradable Potato Starch–Nanocellulose Films: Influence of Starch Content, Nanocellulose Concentration, and Plasticizer Type

ABSTRACT This study aimed to develop and evaluate biodegradable composite films based on potato starch (PS) and nanocellulose (NC) extracted from potato peel residues, as a sustainable alternative to petroleum‐based plastics for food packaging. Films were formulated with 1%–2% NC and 4%–8% PS, and plasticized using glycerol, polyethylene glycol (PEG), or their combination. The highest tensile strength (7473.8 MPa) was achieved in films containing 2% NC, 4% PS, and glycerol (Gly‐2NC‐4PS), whereas the lowest (2775.1 MPa) occurred in PEG‐plasticized films with 1% NC and 4% PS. Increasing PS content from 4% to 8% enhanced TS by ∼8%, while increasing NC from 1% to 2% improved TS by ∼7% and reduced water vapor permeability (WVP) by 1.87 times. Water solubility ranged from 130% to 230%, with the lowest in Gly‐2NC‐4PS and the highest in Gly/PEG‐1NC‐4/8PS films. WVP varied from 20878.3 to 4152.3 kg/(m⋅s⋅Pa) depending on formulation. SEM analysis confirmed uniform, defect‐free structures in glycerol‐based films, indicating efficient dispersion of film components. These results demonstrate that PS/NC films—particularly Gly‐2NC‐4PS—exhibit promising mechanical strength, low solubility, and enhanced barrier properties. The films are suitable for application as biodegradable primary or secondary packaging for dry or semi‐moist food products, contributing to sustainable packaging solutions and agricultural waste valorization.