Influence of moderate electric field on sodium caseinate structure and its techno-functionality

Abstract

This study aimed to evaluate the effect of moderate electric field (MEF) treatment, as a non-thermal technology, on the structure and techno-functionality of sodium caseinate. Colloidal dispersions of caseinate were subjected to different MEF processing conditions (2.56 V cm −1 for 1 and 2 h, 38.46 V cm −1 for 5 and 20 s) and their structural, physical, emulsifying and film-forming characteristics were assessed. The Fourier transform infrared (FTIR) analysis of the caseinate showed higher β-structures and a reduction in random coil conformation after MEF. The MEF-treated dispersions exhibited smaller particle size and developed emulsions with higher physical stability. The process increased the tensile strength (by 6.52–27.37%) and stretchability (by 12.17–54.30%) of caseinate film. A higher glass transition temperature in MEF-processed caseinate films was confirmed by modulated differential scanning calorimetry (MDSC) profiles. The scanning electron microscope (SEM) images showed a more uniform microstructure in treated caseinate films. The results suggest that MEF may be efficiently applied for mild modification of the structure of caseinate resulting in its property improvement. • Moderate electric field (MEF) treatment was applied to sodium caseinate. • MEF presented significant actions on the caseinate structure. • Non-thermal effects of MEF enhanced caseinate techno-functionality. • Treated caseinate yielded emulsions with higher stability and smaller droplet size. • MEF-subjected caseinate films possessed higher mechanical strength and stretchability.