Development of a glue- and heat- sealable acorn kernel meal/κ-carrageenan composite film with high-haze and UV-shield for packaging grease

Starch and protein-derived films can be used as alternatives to plastics; however, the utilization of starch and proteins to this way might exacerbate the global food shortage. In this study, we used discarded acorns to prepare a glue- and heat-sealable packaging film. We evaluated the mechanical characteristics, thermal stability, transmittance, haze, and antibacterial properties of an acorn kernel meal/κ-carrageenan (AKM/κC) composite film. The results showed that the haze and transmittance decreased from 96.74% to 94.50% and from 3.50% to 2.25%, respectively, when glycerol increased from 30% to 50%. The AKM/κC film had excellent UV shielding properties (transmittance at 380–200 nm was 0). The 45 g-AKM/κC film had a maximum sealing strength of 5.09 ± 0.29 N/15 mm at 0.3 MPa for 1 s (115 °C). Beef tallow packaged in 45 g-AKM/κC exhibited an increased POV from 0.0187 to 0.0336 g/100 g after 75 days, which was lower than that in air (0.5209 g/100 g). Our developed film had high haze and UV shielding performance and can be used as a plastic packaging substitute for fat-rich foods.