Development and characterization of cinnamon essential oil – incorporated kudzu starch – based biodegradable films for food packaging applications

Kudzu starch, owing to its excellent film-forming capability, is a promising biodegradable alternative to conventional plastic packaging. In this study, kudzu starch films were fabricated using glycerol and beeswax to enhance flexibility and hydrophobicity, achieving a maximum water contact angle of 116°and a reduced water vapor permeability (WVP) of 1 . 75 ± 0 . 34 × 1 0 − 10 g m m −2 s −1 Pa −1 . The optimized film exhibited a Young’s modulus of 4 . 00 ± 0 . 59 MPa , indicating improved mechanical integrity suitable for food-packaging applications. Antibacterial functionality was introduced by incorporating cinnamon essential oil at concentrations of 1%–3%. The films exhibited significant antibacterial activity against Escherichia coli ( E. coli ), with an inhibition zone diameter reaching 20 . 3 ± 2 . 1 mm at 3% essential oil content. Microstructural and physicochemical analyses using FE-SEM, water absorption, moisture retention, and biodegradation tests confirmed effective modification of the starch matrix. Practical food-packaging performance was evaluated using strawberries as model samples, where films containing 3% cinnamon essential oil significantly reduced the total aerobic bacterial count to 5.75 log 10 CFU/g after 6 days of storage, compared with 7.51 log 10 CFU/g for nylon packaging, and extended the shelf life to 9 days versus 5 days for conventional nylon packaging. These results demonstrate that kudzu starch-based films provide enhanced barrier, antibacterial, and preservation performance, highlighting their strong potential as sustainable food-packaging materials. • Kudzu starch was employed to fabricate biodegradable films for food-packaging applications. • Glycerol and beeswax significantly enhanced the flexibility and hydrophobicity of the films. • Beeswax surface modification increased the water contact angle to as high as 116°. • Kudzu starch films incorporated with cinnamon essential oil exhibited strong antibacterial activity against E. coli . • Strawberries coated with the developed films showed prolonged shelf life and reduced microbial spoilage.