Optimization of Starch Composite Edible Coating Formulation on Fresh-Cut "fuji" Apple through Surface Tension, Wettability and FTIR Spectroscopy

Abstract

Fresh-cut "Fuji" apples are easily oxidised and deteriorated. Therefore, starch composite edible coating formulation were formulated to extend its life span. In this study, the effect of different amount of carboxymethyl cellulose (CMC) (1, 2, 3 and 4% (w/v)), glycerol (1, 2, 3 and 4% (v/v)) and turmeric oil (TO) (50, 175 and 300ppm) were evaluated through surface tension and wettability analysis. Furthermore, the molecular interaction between raw materials of the edible coating film were analysed through FTIR analysis. The results showed that formulation using 2% (w/v) CMC and 2% (v/v) glycerol were the best amount to formulate composite edible coating. Meanwhile, the range of turmeric oil were 50, 175 and 300ppm suitable to be used for further analysis on fresh-cut "Fuji" apples as it does not exceed the general rule of surface tension. The findings for intermolecular reaction of raw materials revealed that there were interactions occurred when citric acid (CA), glycerol and CMC were added; further enhanced functionality of the starch. Besides that, FTIR showed that the functional group in turmeric oil that acts as an active compound to inhibit the oxidation process and microbial activities were present in the edible coating film.