Secondary Structure Characteristic and Mass Spectrometry Identification of Beer Foam Proteins

Abstract:

Beer foam proteins play important roles on beer foam quality.In this study,the secondary structure of beer foam proteins and malt proteins were investigated by Circular Dichroism spectroscopy,and SDS-PAGE pre-fractionation combined with LC-MS/MS was applied to achieve more comprehensive proteome profiles of beer foam proteins.It was indicated that malt proteins mainly existed in α-helix form,while beer foam proteins mainly existed in β-sheet and random coil structure,not showing the typical α-helix structure.The structure characteristic of foam proteins had the advantage to the surface hydrophobic,so as to the beer foam stability.Beer protein bands were positively identified and categorized into 11 protein species,which included protein Z4,LTP1,BDAI-1,and some proteinase inhibitors and trace amount hordein fragments.