Work

Green Valorization of Alfalfa into Sustainable Lignocellulosic Films for Packaging Applications

Year: 2025

Type: article

Abstract: Plastic-based materials dominate the packaging industry. However, their non-biodegradability has increased the need for sustainable alternatives. Biopolymers, mainly lignocellulose from agricultural residues, offer renewable, eco-friendly options in this context. This study reports the development of lignocellulosic films from alfalfa (Medicago sativa) through green valorization of its biomass. Alfalfa lignocellulosic extract (ALE) was extracted using 50% NaOH, solubilized in 68% ZnCl2, crosslinked with CaCl2, and plasticized with sorbitol. The concentrations of ALE, CaCl2, and sorbitol were optimized using the Box–Behnken Design, focusing on increasing tensile strength (TS), elongation at break (EB), and reducing water vapor permeability (WVP) of the films. The optimized film formulation (0.5 g ALE, 453.8 mM CaCl2, 1.5% sorbitol) showed a TS of 11.2 ± 0.7 MPa, EB of 5.8 ± 0.9%, and WVP of 1.2 ± 0.2 × 10−10 g m−1 s−1 Pa−1. The film effectively blocked UV–Vis–IR light and exhibited notable antioxidant activity, making it suitable for packaging light-sensitive and oxidation-sensitive foods. Additionally, it achieved over 90% biodegradation within 29 days under 24% soil moisture. These findings demonstrate a sustainable approach to upcycling agricultural residues into functional products, offering a practical alternative to traditional plastics and supporting a circular bioeconomy, while adding value for alfalfa producers.

Source: Applied Sciences

DOI: 10.3390/app152211889

Authors: Sandeep Paudel, Srinivas Janaswamy

Institution: South Dakota State University

Language: English

Topic: Nanocomposite Films for Food Packaging

Subfield: Biomaterials

Field: Materials Science

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: gold

Estimated APC paid: $2,896