EFFECTS OF PULSED ELECTRIC FIELD ON THE STRUCTURAL AND EMULSIFYING PROPERTIES OF DAIRY PROTEINS.

Pulsed electric field (PEF), as an emerging eco-friendly technology, has been used in the food industry for the inactivation of enzymes and microorganisms. PEF was also utilized to change the structural and techno-functional properties of food proteins. This abstract represents our latest studies on the applications of PEF on milk proteins. The first study aimed to investigate the effects of PEFassisted glycation of bovine serum albumin (BSA) and soluble potato starch on the emulsifying performance of BSA/starch conjugates. The physicochemical and emulsifying properties of the BSA/starch conjugates were investigated. PEF at 3.5-5.7 kV cm-1 decreased the fluorescence emission intensity of BSA/soluble starch conjugates. Furthermore, PEF-treated (3.5-5.7 kV cm-1) BSA/soluble starch conjugates had better emulsifying properties (lower droplet size of emulsions) and protein solubility compared to native BSA and untreated BSA/soluble starch mixtures. The aim of the second study was to examine the effects of PEF treatment (0-30 kV cm-1) on the structural properties of casein micelles (CSM). At 10 kV cm-1, PEF treatment caused a significant increase in the particle sizes, absolute potential, turbidity, and surface hydrophobicity values while a decrease in the solubility (%) of CSMs was observed. Moreover, the results of Fourier transform infrared spectroscopy (FTIR) analysis confirmed that PEF treatment influenced the particle sizes and improved the protein solubility of CSMs. Moreover, the deconvolution analysis of the Amide region (1600-1700 cm-1) of FTIR spectra showed that PEF treatment reduced the a-helix content but increased the ß-sheet of CSMs. Raman spectra confirmed that PEF treatment > 10 kV cm-1 buried tyrosine residues in a hydrophobic environment and the decrease in the a-helix was also proved. [ABSTRACT FROM AUTHOR]