Denaturation Time and Temperature Effects on Solubility, Tensile Properties, and Oxygen Permeability of Whey Protein Edible Films

Abstract

ABSTRACT Whey protein film solubility decreased as film‐forming solution heating time and temperature increased. No differences were observed in solubility between films soaked in water at 25 °C for 24 h and 100 °C for 4 min. However, the degree of swelling was significantly larger for films soaked at 100 °C. Films became stiffer, stronger and more stretchable as film‐forming solution time and temperature were increased. Oxygen permeability (OP) was lower for films made from heat‐denatured whey protein than for films made from native whey protein. Results suggest that an increase in covalent cross‐linking, as heat denaturation of the whey protein increases, is accountable for film water insolubility, higher tensile properties and lower OP.