Physical and Molecular Properties of Wheat Gluten Films Cast from Heated Film‐Forming Solutions

Abstract

ABSTRACT The effect of heating film‐forming solutions on physical and molecular properties of cast wheat gluten (WG) films was determined. Glycerol‐plasticized films were cast from alkaline (pH 10), heat‐treated (55,75, or 95°C for 10 min) solutions of WG in aqueous ethanol. Protein solubility (PS) of films in water decreased (P<0.05) with increasing temperature. Gel permeation chromatograms showed reduced extractability of protein fractions other than ω‐gliadins in WG films. This reduced extractability was due to disulfide (S‐S) bond formation. SDS‐PAGE patterns of native WG and WG film samples suggested increased cross‐linking through covalent S‐S bonds in films from solutions heated at 75 or 95°C. Water resistance in potential packaging applications of WG edible films could be modified by adjusting heat‐treating temperature.