Fabrication and Characterization of Pectin-Chitosan Edible Coatings with a Cosmos caudatus Leaf Extract for Tomato Preservation

Source abstract

Abstract An edible coating based on pectin-chitosan and Cosmos caudatus leaf extract has been created. Cosmos caudatus leaf extract, which contains several bioactive compounds, aims to produce an edible coating with antibacterial properties. C. caudatus extract was incorporated at concentrations of 1, 2, and 3 g into a mixture of 1.5 g of pectin and 1 g of chitosan. The edible coating was applied to the tomatoes using the dipping method. The coated tomatoes were analyzed for 21 days at room temperature to determine the weight loss value. The edible coating was characterized, including FTIR analysis, X-ray diffraction, surface morphology, thermal stability, viscosity, and antibacterial activity. The research results reveal that C. caudatus extract contains anthocyanins with antibacterial properties, has an amorphous crystalline structure, and has a textured surface with partial aggregation. Thermal stability analysis using differential scanning calorimetry (DSC) shows a decrease in thermogravimetric (TG) values with increasing extract concentration. The optimal weight loss (6.18%) was found in the pectin-chitosan composition containing 3 g of C. caudatus extract. At this concentration, the inhibition zones against Escherichia coli and Staphylococcus aureus were 16.4 and 15.6 mm, respectively. These findings indicate that the C. caudatus leaf extract, particularly at 3 g, enhances the antibacterial properties of the edible pectin-chitosan coating, demonstrating its potential to extend the shelf life of tomatoes safely.