Biodegradable Levan/Chitosan Composite Films: Development and Application in Beef Filet Packaging

This study developed biodegradable levan-chitosan composite films for beef filet packaging, optimizing their functional properties and assessing their efficacy in food preservation. Films were prepared via solution casting using varying levan-chitosan ratios (100:0, 75:25, 50:50, 25:75, 0:100) with glycerol (30%) as a plasticizer. The L25:C75 formulation exhibited superior mechanical properties (tensile strength: 15.43 ± 0.04 MPa; elongation at break: 35.37 ± 1.12%) and high-water solubility (46.64 ± 0.37%). FTIR analysis confirmed intermolecular interactions between levan and chitosan. The films demonstrated strong antioxidant activity (91% ABTS•+ inhibition) and broad-spectrum antibacterial effects, with inhibition zones of 18 ± 0.30 mm against E. coli and 16 ± 0.20 mm against S. aureus. When applied to beef filets stored at 4 °C for 7 days, the L25:C75 films reduced total viable bacterial counts by 1.8 log CFU/g compared to LDPE packaging. Biodegradability tests revealed a 68% degradation rate for high-levan films (L75:C25) after 14 days in soil. These results highlight the potential of levan-chitosan films as sustainable, active packaging materials to extend food shelf life while addressing environmental concerns.