Enhancing the Mechanical Properties of Carrageenan-Tapioca Starch Biocomposite Films for Sustainable Food Packaging

Abstract

The global shift toward sustainable materials has spurred research into biodegradable food packaging options. This study explores into the improvement of carrageenan-based biocomposite films by using tapioca starch (TS) at various concentrations (0.15 g – 0.30 g). Films were made by solution casting with polyethylene glycol (PEG) as a plasticizer and isovanillin as a natural crosslinker. Mechanical, rheological, and structural parameters were investigated, including tensile strength, viscosity, Fourier Transform Infrared (FTIR) spectra and Area Under Peak (AUP) of infrared spectra analysis. The results revealed that carrageenan incorporated with 0.20 g of tapioca starch (TS0.20) produced the highest tensile strength (2,125.84 MPa) and viscosity (141.55 P), balancing elasticity and film strength. At TS0.20, FTIR analysis with AUP quantification revealed higher intermolecular (20.783) and intramolecular (7.985) OH bonding, as well as better O-SO₃ (13.737) and C=O (10.050) intensities, indicating stronger hydrogen bonding and sulfate-carbonyl interactions. However, higher TS concentrations (more than 0.20 g) resulted in lower AUP values, lower tensile strength, and functional groups intensity values, indicating polymer network breakdown. These findings show that moderate starch incorporation improves mechanical and functional qualities, pointing to carrageenan-tapioca starch films as promising biodegradable food packaging alternatives.