title: Understanding the distribution of natural wax in starch-wax films using synchrotron-based FTIR (S-FTIR).
abstract: High amylose starch-glycerol (HAG) films were produced incorporating beeswax, candelilla wax and carnauba wax in the presence and absence of Tween-80 in order to determine the distribution of wax in the films during the film formation process. The distribution of these waxes within the film was studied using Synchrotron based Fourier Transform Infrared Spectroscopy (S-FTIR) which provided 2D mapping along the thickness of the film. The incorporation of 5% and 10% wax in HAG films produced randomly distributed wax or wax-rich domains, respectively, within these films. Consequently, the addition of these waxes to HAG increased the surface roughness and hydrophobicity of these films. The addition of Tween-80 caused variations in wax-rich bands within the films. The HAG+carnauba wax+Tween-80 films exhibited domed wax-rich domains displayed with high integrated CH2 absorption value at the interior of the films, rougher surface and higher contact angle values than the other films. The S-FTIR 2D images indicated that the distribution of wax in starch-wax films correlated with the roughness and hydrophobicity of the starch-wax films.
authors: School of Health Sciences, University of Ballarat, VIC 3353, Australia.
authors: Delina
authors: D
authors: Muscat
authors: IR Beamline, Australian Synchrotron, Clayton, VIC 3168, Australia.
authors: Mark J
authors: MJ
authors: Tobin
authors: Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC 3219, Australia.
authors: Qipeng
authors: Q
authors: Guo
authors: School of Health Sciences, University of Ballarat, VIC 3353, Australia; School of Applied Sciences, RMIT University, City Campus, Melbourne, VIC 3001, Australia. Electronic address: b.adhikari@ballarat.edu.au.
authors: Benu
authors: B
authors: Adhikari
keywords: Films; High amylose starch; Natural wax; Surface hydrophobicity; Synchrotron-FTIR