title: Surface characterization of 7S and 11S globulin powders from soy protein examined by X-ray photoelectron spectroscopy and scanning electron microscopy.
abstract: In this study the surface composition of 7S and 11S globulin powders from soybean proteins by aqueous buffer and reverse micelle extractions had been examined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Analysis by XPS revealed that the O and N atomic percentage of 7S and 11S globulin surfaces from bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelle was higher than from aqueous buffer, but the C atomic percentage was lower. The O/C ratio of the 7S globulin powder from aqueous buffer and reverse micelle was similar while significant differences were obtained in the O/C ratio of the 11S globulin powder, N/C atom ratios of the 7S and 11S globulin powders and high-resolution XPS C 1s, N 1s, O 1s spectra. Powder microstructure after reverse micelle treatment showed the presence of small pores, indicating the effect of reverse micelle on the 7S and 11S globulin structure. The obtained results indicated that the reverse micelle could affect the C, O and N components on the surface of soybean proteins.
authors.affiliation: Institute of Agro-Food Science & Technology, Shandong Academy of Agricultural Sciences, No. 202, Gongyebei Road, Jinan 250100, China. zhaoxy_2201@163.com
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhao
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Zhu
authors.forename: Fangling
authors.initials: F
authors.lastname: Du
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ao
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
mesh_terms: D002021:Buffers; D002244:Carbon / Q000737:chemistry; D005612:Freeze Drying; D005916:Globulins / Q000737:chemistry*; D008823:Micelles; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D011208:Powders / Q000737:chemistry; D030262:Soybean Proteins / Q000737:chemistry*; D013386:Succinates / Q000737:chemistry; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D002021:Buffers; D005916:Globulins; D008823:Micelles; D011208:Powders; D030262:Soybean Proteins; D013386:Succinates; C511925:bis(2-ethylhexyl)sulfosuccinate; D014867:Water; D002244:Carbon; D009584:Nitrogen; D010100:Oxygen