The physicochemical characteristics and hydrophobicity of high amylose starch–glycerol films in the presence of three natural waxes

Abstract The film forming behaviour and hydrophobicity of high amylose (HA) starch in the presence of three different natural waxes (beeswax, candelilla wax and carnauba wax) were studied in the presence and absence of Tween-80. The HA starch:glycerol (G) ratio was maintained at 80:20 (on dry solid basis) and the concentration of wax was varied from 5% and 10% (w/w). The melted wax samples were homogenized with HAG dispersion with or without Tween-80 and the films were prepared by solution casting. The hydrophobicity and water-barrier properties in these films were determined by using contact angle (CA), water vapour permeability ( K w ) tests, and water sorption isotherm at 0.529 RH and 20 °C. The K w values of the HAG films decreased significantly ( p K w values significantly ( p 80.0° both at 5% and 10% (w/w) wax concentration. These higher CA values in HAG + carnauba wax + Tween-80 films were found to be related to the higher surface roughness in these films.