Effects of Pulsed Electric Field on the Physicochemical and Structural Properties of Micellar Casein

Abstract

Pulsed electric field (PEF) as a green processing technology is drawing greater attention due to its eco-friendliness and potential to promote sustainable development goals. In this study, the effects of different electric field strengths (EFS, 0–30 kV/cm) on the structure and physicochemical features of casein micelles (CSMs) were investigated. It was found that the particle sizes of CSMs increased at low EFS (10 kV/cm) but decreased at high EFS (30 kV/cm). The absolute ζ-potential at 30 kV/cm increased from −26.6 (native CSMs) to −29.5 mV. Moreover, it was noticed that PEF treatment leads to changes in the surface hydrophobicity; it slightly increased at low EFS (10 kV/cm) but decreased at EFS > 10 kV/cm. PEF enhanced the protein solubility from 84.9 (native CSMs) to 87.1% (at 10 kV/cm). PEF at low EFS (10 kV/cm) intensified the emission fluorescence spectrum of CSMs, while higher EFS reduced the fluorescence intensity compared to native CSMs. Moreover, the analysis of the Amide Ι region showed that PEF-treated CSMs reduced the α-helix and increased the β-sheet content. Raman spectra confirmed that PEF treatment > 10 kV/cm buried tyrosine (Tyr) residues in a hydrophobic environment. It was also found that PEF treatment mainly induced changes in the disulfide linkages. In conclusion, PEF technology can be employed as an eco-friendly technology to change the structure and physiochemical properties of CSMs; this could improve their techno-functional properties. © 2023 by the authors. --//-- Taha A., Casanova F., Talaikis M., Stankevič V., Žurauskienė N., Šimonis P., Pakštas V., Jurkūnas M., Gomaa M.A.E., Stirkė A.; Effects of Pulsed Electric Field on the Physicochemical and Structural Properties of Micellar Casein; (2023) Polymers, 15 (15), art. no. 3311, DOI: 10.3390/polym15153311; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85167837386&doi=10.3390%2fpolym15153311&partnerID=40&md5=4b7f085bdb3c549653bb18890ba7b081. Published under the CC BY 4.0 licence.