Microfibrillated cellulose films from agri-food wastes and plant residues for food packaging applications – A comparative investigation

Abstract

Cellulose from three agri-waste feedstocks—giant cane, Posidonia oceanica seagrass, and coffee silverskin—was processed into aqueous dispersions (1% by weight) of microfibrillated cellulose (MFC) via high-pressure homogenization (HPH) to produce stand-alone films for potential food packaging applications. Rheology, stability, and morphology of dispersions, as well as optical, barrier, mechanical, morphological, and surface properties of the resulting films were evaluated, with Sylvicta® used as a commercial reference. Atomic Force Microscopy (AFM) confirmed successful MFC production (average diameter < 100 nm) after HPH. The dispersions showed good stability (ζ-potential < 30 mV), shear-thinning, and strong-gel behavior (G’/ G’’ ≈ 10). Regardless of cellulose source, the films performed similarly to the commercial solution, including excellent oxygen barrier properties [oxygen transmission rate < 0.01 cm³ (STP) m⁻² day⁻¹ under dry test conditions], high stiffness (Young’s modulus ≈ 7.5 GPa), tensile strength (≈ 85 MPa), and effective UV-shielding. Surface wettability differed: the commercial sample exhibited a higher contact angle (≈ 115°) than the prepared films (≈ 55–95°). Nonetheless, all samples showed initial spreading of the water droplet followed by absorption. This study demonstrates the potential of valorizing agri-food waste and plant residues into sustainable, high-performance cellulosic films for food packaging. The approach supports circular economy strategies and helps reduce the environmental impact of plastics.