title: Spectroscopic evaluation of effects of heat treatments on the structures and emulsifying properties of caseins.
abstract: The effects of heat treatment (heating temperature and pH) on the structures and emulsifying properties of caseins were systematically studied by spectroscopy. Heat treatment from 60 to 100 degrees C resulted in an increase in their fluorescence intensity, hydrodynamic diameter, turbidity and emulsifying activity index, but decreased the size polydispersity of caseins. In the pH range of 5.5 to 7.0, the fluorescence intensity, hydrodynamic diameter, turbidity and emulsifying properties decreased with increased heating pH, but the size polydispersity of caseins increased with increased pH. The relationship between the surface fluorescence intensity and emulsifying activity was also investigated, revealing a correlation coefficient of 0.90. These results suggested that heat treatment could be used to modify the structures and emulsifying properties of caseins by appropriately selecting heating conditions.
authors.affiliation: College of Information and Electrical Engineering, China Agricultural University, Beijing 100094, China. zhanghaocau@yahoo.com.cn
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Peng-Jie
authors.initials: PJ
authors.lastname: Wang
authors.forename: Xin-Gen
authors.initials: XG
authors.lastname: Lei
authors.forename: Hong-Ju
authors.initials: HJ
authors.lastname: Yang
authors.forename: Lu-Da
authors.initials: LD
authors.lastname: Zhang
authors.forename: Fa-Zheng
authors.initials: FZ
authors.lastname: Ren
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zheng
mesh_terms: D002364:Caseins / Q000737:chemistry*; D045703:Emulsifying Agents; D004655:Emulsions; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D002364:Caseins; D045703:Emulsifying Agents; D004655:Emulsions