Preparation and Application of Edible Chitosan Coating Incorporating Natamycin

In this paper, edible composite coatings, which used chitosan (CTS) as the matrix material, glycerol as the plasticizer, and natamycin as the antibacterial material, were prepared and composite films were prepared by a casting method. Taking cherry tomatoes as the research models, the optimal preservation effect of the composite coating was achieved using 10 g/L CTS, 2.5 g/L glycerol, and 125 mg/L natamycin under conditions of 25 °C and 50% RH. The thickness, transparency, water vapor transmittance (WVT), tensile strength (TS), and elongation at break (EB) of composite film were measured and the results showed the film prepared using 10 g/L CTS, 2.5 g/L glycerol and 125 mg/L natamycin was the best. The direct application of the optimal coating to cherry tomatoes kept the cherry tomatoes valuable for 20 days. The weight loss rate and hardness loss rate were reduced by 22.13% and 12.55%, respectively. The total soluble solid (TSS) content and vitamin c (Vc) content were increased by 2.54% and 20.35%, respectively. The malondialdehyde (MDA) content and peroxidase (POD) activity were decreased by 19.38% and 28.03%, respectively. Based on the significant preservation effect of the composite coating, it is expected to be widely used in the preservation of fruits and vegetables with skin morphologies similar to cherry tomatoes.