Simulation and Experimental Validation of the Denaturation of a Whey Protein-Based Coating During Convection and/or Infrared Drying on a Plastic Film and Influence on its Oxygen Barrier Properties

ABSTRACT

The in-process denaturation of native whey protein-based coatings, film temperature, residual humidity, and protein degree of denaturation was simulated with combined existing models. The simulation was validated experimentally through determining the degree of denaturation of the protein in the coating. Whey protein-based formulations were applied, and denaturation was induced via infrared heating during the drying process. The oxygen transmission rate was measured and correlated with the degree of denaturation. The observed influence of the denaturation degree allowed the identification of a critical denaturation degree improving oxygen barrier. The developed simulation appears as an efficient tool for optimizing the processing and properties of protein-based materials.

GRAPHICAL ABSTRACT

KEYWORDS:

• Degree of denaturation
• infrared heating
• oxygen permeability
• thin-layer drying
• whey protein isolate

Acknowledgment

The authors want to acknowledge the support from their respective colleagues Dr. Klaus Noller, Dr. Matthias Reinelt, and Prof. Andrea Lazzeri for the fruitful discussion and support. Furthermore, they want to thank D. Schweer, S. Eib, and B. Krimmel for their support on measuring the degree of denaturation of the whey protein-based films and coatings, Ivan Vilaró for the set-up of the test rig for coating/drying, and finally the company Lajovic Tuba d.o.o. for supplying the coated films commented in the Conclusion.