Structure and emulsifying properties of whey protein isolate: Effect of safflower yellow concentration

Publication date: Available online 24 January 2020Source: LWTAuthor(s): Wei Chen, Tianqi Li, Haiying Yu, Chenglong Ma, Xindi Wang, Abdul Qayum, Juncai Hou, Zhanmei JiangAbstractThe effects of different concentrations of safflower yellow (SY) on the structure and emulsifying properties of whey protein isolate (WPI)-SY complexes were investigated at 25 °C for 0, 3 and 6 days. About 92.6%, 93.75%, and 95.47% of the free sulfhydryl groups from the WPI-SY complexes were lost over 0, 3 and 6 days, respectively, in the presence of 2% SY. Meanwhile, the fluorescence intensity of the WPI-SY complexes also weakened obviously, indicating that the tryptophan residues micro-environment underwent certain changes. Furthermore, fourier transform infrared spectroscopy demonstrated that SY increased the proportion of WPI β-sheets and decreased the proportion of β-turn structures. The particle size of the WPI-SY complexes increased as the SY concentration was increased from 1 to 4%. Compared with SY or WPI, the antioxidant activity of the WPI-SY complexes was enhanced with SY ranged from 0.25 to 4%. SY triggered emulsifying activity of WPI initially increased and then decreased. Therefore, SY could enhance the emulsifying properties and antioxidant activities of WPI-SY.
Source: LWT Food Science and Technology - Category: Food Science Source Type: research