Evaluation of the Food Barrier and Mechanical Properties of Carrageenan-Starch Composite Films

Single use plastics are a leading source of microplastics that have been detected along the food chain. This study evaluated the potential of starch (ST) and carrageenan (CRG) in packaging film formulation. CRG isolated from the seaweed (SW) Eucheuma denticulatam was blended with starch and cast to obtain films whose moisture content (MC), total soluble matter (TSM), degree of solubility (DS), water vapor permeability (WVP), opacity (O), contact angles (CA), moisture absorption (MA), and percent elongation (PE) were evaluated. The films' morphology, crystallinity, opacity, thermal profile, and functional groups were then studied by scanning electron microscopy, powder diffraction, UV-Vis, thermal gravimetry, and infrared spectroscopy. From the results obtained, the SWF films exhibited a higher MC, DS, and TSM than CRG and CRG-ST films but lower DC values. The PE of CRG films was lower than that of SWF (30%) though incorporation of ST increased the PE of CRG-ST. However, SWF films had WVP of 2.25 x 10-7 gs-1m-1Pa-1, compared to 3.65 x 10-7 gs-1m-1Pa-1 of CRG, 2.73 x 10-7 gs-1m-1Pa-1 of CRG-ST and a moisture absorption of 29.29 +/- 3.5 as compared to 17.29 +/- 0.87 of CRG and 23.80% +/- 4.12% of CRG-ST. The opacities were found to be 41.02, 79.89, and 42.23 for SWF, CRG, CRG-ST while the contact angles were found to be 72.86, 80.93, 65.57 for SWF, CRG, and CRG-ST, respectively. Moreover, the films were impermeable to vegetable oil, had carbohydrate functional groups, good thermal stabilities, and trace micronutrients. In conclusion, this study formulated packaging films with enhanced food barrier and mechanical properties that can potentially replace single use packaging films.