The paper analyzes the possibility of replacing the polyethylene packaging from food products with biodegradable packaging obtained from biopolymers. The proposed packaging materials were obtained from polysaccharides (alginate, agar), glycerol as plasticizer. To improve the properties necessary for the coating materials, two groups of membranes were made, one with ascorbic acid (AA, 0.1-0.45 g) in 150 mL filmogenic solution and the other with calcium chloride (CaCl2, 0.02-0.1 g) in 150 mL filmogenic solution. The membranes were analyzed for mechanical properties, light transmission, transparency and barrier properties (water vapor, oxygen, or fatty substances). The results demonstrated that the addition of AA (0.1 g), increases tensile strength, transparency, oxygen and water barrier properties. On the other hand, the addition of calcium chloride (0.08 g) increased the hardness, tensile strength and opacity of the membranes. Moreover, it ensured a uniform distribution of the mixture components. The uniformization of the mixture components in the presence of AA and CACl2 was observed by SEM and roughness analysis. Hydrogen bonding interactions between the biopolymers and the additives used were highlighted by FTIR analysis. All membranes have shown very good UV absorption. The results suggest that agar/alginate/glycerol membranes with AA and CaCl2 have the potential to be used in an active food packaging system.
Keywords: ascorbic acid; biodegradable packaging; biopolymers; calcium chloride.