Effect of Coating Materials on the Properties of Chitosan-Starch-Based Edible Coatings

Edible coating is a thin layer on the surface that is used to extend shelf life of the fruit. The characteristics of the materials used and the properties of each substance in the coating solution will affect the quality of the edible coating. In this study, the use of chitosan at different concentrations has been assessed to produce an effective edible coating. Chitosan-starch edible coating with 1.5% (w/v) chitosan contents were chosen to give the best surface tension and wettability to coat fruit. Their structural and functional properties were also characterized through FTIR. Outcome from this study found that the shifting of peaks and the changes in the spectra were resulted due to the hydrogen bonding between OH and NH3+ of chitosan and OH group of starch. These shifts shown that the addition of glycerol promoted the hydrogen bonding interactions and plasticization effect of glycerol due to the hydrophilic nature. Additional of turmeric essential oil in the edible coating could enhance more its function to protect fruit and serves as antimicrobial agent due to the presence of phenolic group in its structure.