Cold plasma-induced structural modifications and their impact on functional properties of whole egg powder.

BACKGROUND: Spray-dried whole-egg powder is a nutrient-rich ingredient widely used in the food industry. However, thermal stress during spray drying partially denatures egg proteins, thereby reducing functional performance. Although cold plasma has been investigated for modifying food proteins, its application to improve the structural and functional properties of spray-dried whole egg powder remains largely unexplored. This study evaluated the effects of cold plasma applied to the whole-egg powder to evaluate the structure-function relationship. RESULTS: Structural modifications were characterized by circular dichroism, Fourier transform infrared spectroscopy, X-ray diffraction, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and dynamic rheology. Circular dichroism analysis revealed controlled, cold plasma-induced changes in protein secondary structure, characterized by a reduction in α-helical content and an increase in β-sheet content. Fourier transform infrared spectroscopy and SDS-PAGE further confirmed protein conformational changes with limited fragmentation. Rheological analysis showed increased viscoelastic performance of the reconstituted dispersions following plasma treatment. Functionally, water and oil absorption capacities increased by 73% and 160%, respectively, whereas emulsion stability and foaming capacity improved by 17.1% and 152.75%, respectively. Cold plasma treatment also altered the amino acid and fatty acid profiles, with non-essential amino acids increasing from 25.18 to 27.22 g 100 g-1, essential amino acids decreasing from 25.04 to 22.79 g 100 g-1, unsaturated fatty acids decreasing by 16.08%, and saturated fatty acids increasing by 13.33%. CONCLUSION: These findings show that atmospheric cold plasma can be used as a non-thermal method to modify the structure-function relationship of spray-dried whole egg powder, offering a promising means to improve its functional performance in advanced food processing applications. © 2026 Society of Chemical Industry.