UV Radiation Induced Cross-Linking of Whey Protein Isolate-Based Films

Abstract EN

Casted whey protein films exposed to ultraviolet irradiation were analyzed for their cross-linking properties and mechanical and barrier performance.

Expected mechanical and barrier improvements are discussed with regard to quantification of the cross-linking in the UV-treated whey protein films.

Swelling tests were used to determine the degree of swelling, degree of cross-linking, and cross-linking density.

When the UV radiation dosage was raised, a significant increase of the tensile strength as well as an increase in Young’s modulus was observed.

No significant changes in water vapor and oxygen barrier properties between the UV-treated films and an untreated reference sample could be observed.

The cross-linking density and the degree of cross-linking significantly increased due to UV radiation.

Combined results indicate a disordered protein network in cast films showing locally free volume and therefore only minor mechanical and barrier improvements.