Effect Of Pulsed Electric Fields Treatment On Structure,Immunogenicity And Glycation Properties Of β-lactoglobulin

In this paper,spectroscopy was used to study the conformation structure and functional properties of β-lactoglobulin by pulsed electric fields(PEF)combing with glycation treatment.By high-resolution Orbitrap Fusion mass was used to study the effect of PEF on the β-lactoglobulin glycation.Inhibition ELISA was used to investigate antigenicity and the Ig E ability of β-lactoglobulin by PEF combing with glycation treatment.Results are as follows:1.We evaluated antigenicity and the Ig E ability of β-lactoglobulin changes of β-lactoglobulin by differrent the electric field intensity(5-35 k V/cm)pulsed electric fields(PEF)pretreatment combined with glycation.Glycation after PEF pretreatment,antigenicity and allergenicity were all decreased.And PEF pretreatment could promote the decrease of antigenicity.When treating by glycation after preteated under 25 k V/cm for 90 μs,the antigenicity of β-Lg decreased by about 72.9 %.Allergenicity firstly increased and then decreased with the increasing of PEF treatment intensity,the lowest allergenicity of β-LG was observed at 15 k V/cm for 90 μs.As the electric field intensity was increased,the allergenicity firstly increased and then stability.2.We studied structural of β-lactoglobulin glycated with PEF pretreatment by analysis of SDS-PAGE,circular dichroism spectra,intrinsic fluorescence,surface hydrophobicity.After treating by glycation with PEF pretreatment,the free amino content of β-Lg decreased significantly,the molecular weight of β-Lg increased and dimer generated.The content of α-helix and β-turns decreased while the content of β-sheet and random coil increased.The intrinsic fluorescence intensity and surface hydrophobicity reduced,the intrinsic fluorescence intensity reached the minimum at 35kv/cm for 90 μs.And the free sulfhydryl content firstly increased then decreased with the increase of electric filed intensity.3.The high-resolution Oribitrap mass spectrometry was used to investigate the glycation sites.Under 25 k V/cm,PEF pretreatment could promote the glycation reaction increase the number of glycation sites.The results suggested pretreatment by PEF change the structure of β-lactoglobulin.4.The solubility,emulsifying activity and emulsifying stability,oxidation resistance(DPPH radical scavenging ability and Trolox equivalent antioxidant capacity)of the glycation combined with PEF pretreatment were all significantly increased.