The effects of pasteurization on caseinate-based edible film solutions

Authors: McAnulty, Michael; Plumier, Benjamin; Guron, Giselle Kris; Malcolm, Sherell; Oest, Adam; Miller, Amanda; Garcia, Rafael; Renye Jr, John

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Dairy proteins can be used to make edible films, but reconstituted dairy solutions must be pasteurized to comply with U.S. food safety regulations. It was not known if pasteurization of dairy film solutions affects properties of their resulting films. This study revealed that pasteurization of film solutions reduced microbial counts while not affecting textural and water vapor barrier properties of the resulting films. However, pasteurization decreased viscosity and affected film solution stability, which can affect storage and film casting. Ultimately, pasteurized dairy protein films were generated, demonstrating the viability of pasteurization technologies for preserving film solutions.

Technical Abstract: Edible films based on the main dairy protein casein have been developed, but widespread adoption will require pasteurization, and nothing is known about the effects of pasteurization on properties of the solutions themselves or their resulting films. This study investigated alterations in calcium and sodium caseinate based film formulations due to commonly used pasteurization techniques: long temperature long time (LTLT), high temperature short time (HTST), and ultra high temperature (UHT). All pasteurization conditions resulted in films with most textural properties and water vapor permeabilities having no significant changes in comparison to those made from non-pasteurized solutions. The only exceptions were films from the UHT processed calcium caseinate and HTST processed sodium caseinate solutions having increased tensile strength and decreased yield stress, respectively. The solutions themselves, however, changed dramatically with reduced viscosity, and storage and loss moduli (representing stiffness and energy dissipating behavior, respectively) after pasteurization, especially with higher temperatures involved. The pasteurized solutions would thus be easier to process, except more complications may arise during casting. The particle size distribution of the calcium caseinate, but not the sodium caseinate, based solution changed with all pasteurization techniques to become more polydisperse. While LTLT and HTST processing did not change solution stability, UHT increased stability of the sodium caseinate film solution, but decreased the stability of the calcium caseinate film solution with a greater tendency to separate over time. UHT processing was the only pasteurization technique that proved effective in reducing microbial counts to below the limit of detection (1 log10 CFU mL-1). Overall, we demonstrated that caseinate-based films may be pasteurized without concern of obvious changes to properties of resulting films, however, considerable rheological changes to the film forming solutions are likely to occur.