Pectin/sodium alginate/xanthan gum edible composite films as the fresh-cut package

Due to the convenience, fresh-cut vegetables or fruits as the emerging commercial products have attracted much attention in recent years. However, the preservation of food with high quality remains a big challenge. In this study, one novel kind of edible composite film (PAX) consisted of pectin, sodium alginate (SA), and xanthan gum (XG) was well developed. The optimum concentrations for pectin and SA in PAX film based on the shearing viscosity were 6 g/L and 5 g/L, respectively. Upon this condition, the experimental results from the response surface methodology showed that the tensile strength for the optimized PAX (PAX_O) film can reach the maximum value of 29.65 MPa at the concentration of 4 g/L XG, 18 g/L glycerol, and 20 g/L CaCl₂. The corresponding elongation at break was 19.02% and the water vapor transmission rate was evaluated to be 18.12 × 10^-11 g/(m²·s·pa). Furthermore, the nanocomposites in terms of coating or films were used to keep fresh-cut potatoes, where they exhibited different efficiencies in food preservation with the order: PAX_O coating + CaCl₂ ≈ PAX_O coating > PAX_O film > sterile water. All the results indicated that the as-prepared PAX_O film or PAX_O solution could be good candidates in packaging preservation.