Physicochemical Properties of Starch-Chitosan Film with Lemongrass Essential Oil

Biopolymer films integrated with natural antimicrobial represent a sustainable strategy for enhancing food safety and shelf life. This study characterizes a functional starch-chitosan (S-CH) film incorporated with lemongrass essential oil (LEO). GCMS identified α-citral as the primary antimicrobial component of the LEO. The film was prepared using the casting technique, and the influence of LEO concentration on mechanical properties, hydrophobicity and surface morphology were determined. The findings show that the tensile strength and elongation at break of the S-CH-LEO films were lower than those of the S-CH film, making them brittle and less stretchy. The incorporation of LEO from 0.05% to 0.15% had increased tensile strength and elongation at break from 0.143 MPa to 0.873 MPa and from 3.81% to 8.63%, respectively. The hydrophobicity of S-CH-LEO films increased with the increase in LEO, as evidenced by a higher water contact angle range between 52.30° and 84.80°. S-CH-LEO 0.15% film was the best formulation, with a tensile strength of 0.873 MPa, an elongation at break of 8.63%, and a contact angle of 71.50°. This study shows that S-CH-LEO films improve moisture resistance, a critical factor for extending the food shelf life. Therefore, despite the lower tensile strength and elongation at break, the resulting improvements in water resistance and functional bioactivity suggest that S-CH-LEO films are viable solution for active food packaging applications.