Premium
Physical Properties of Whey Protein Coating Solutions and Films Containing Antioxidants
Author(s) -
Han J.H.,
Krochta J.M.
Publication year - 2007
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2007.00358.x
Subject(s) - whey protein , coating , chemistry , food science , chemical engineering , organic chemistry , engineering
Antioxidants (ascorbyl palmitate and α‐tocopherol) were incorporated into 10% (w/w) whey protein isolate (WPI) coating solution containing 6.67% (w/w) glycerol (WPI:glycerol = 6:4). Before incorporation, the antioxidants were mixed using either powder blending (Process 1) or ethanol solvent‐mixing (Process 2). After the antioxidant mixtures were incorporated into heat‐denatured WPI solution, viscosity and turbidity of the WPI solutions were determined. The WPI solutions were dried on a flat surface to produce WPI films. The WPI films were examined to determine transparency and oxygen‐barrier properties (permeability, diffusivity, and solubility). WPI solution containing antioxidants produced by Process 1 and Process 2 did not show any difference in viscosity and turbidity, but viscosity was greater for the WPI solution with rather than without antioxidants. WPI films produced by Process 2 were more transparent than the films produced by Process 1. Oxygen permeability of Process 1 film was lower than Process 2 film. However, both the diffusivity and solubility of oxygen were statistically the same in Process 1 and Process 2 films. Both control WPI films and antioxidant‐containing WPI films had very low oxygen solubility, comparable to polyethylene terephthalate films. Permeability of antioxidant‐incorporated films was not enhanced compared to control WPI films.