Edible Carrageenan Films Reinforced with Starch and Nanocellulose: Development and Characterization

Currently, from the sustainable development point of view, edible films are used as potential substitutes for plastics in food packaging, but their properties still have limitations and require further improvement. In this work, novel edible carrageenan films reinforced with starch granules and nanocellulose were developed and investigated for application as a bio-based food packaging system. The nanocellulose was used to improve film mechanical properties. Aloe vera gel was incorporated for antibacterial properties. Glycerol and sesame oil were added as plasticizers into the nanocomposite film to improve flexibility and moisture resistance. The interactions between charged polysaccharide functional groups were confirmed by FTIR spectroscopy. The migration of starch particles on the upper film surface resulting in increased surface roughness was demonstrated by scanning electron and atomic force microscopy methods. Thermogravimetric analysis showed that all films were stable up to 200 degrees C. The increase in nanocellulose content in films offered improved mechanical properties and surface hydrophilicity (confirmed by measurements of contact angle and mechanical properties). The film with a carrageenan/starch ratio of 1.5:1, 2.5 mL of nanocellulose and 0.5 mL of glycerol was chosen as the optimal. It demonstrated water vapor permeability of 6.4 x 10-10 g/(s m Pa), oil permeability of 2%, water solubility of 42%, and moisture absorption of 29%. This film is promising as a biodegradable edible food packaging material for fruits and vegetables to avoid plastic.