Journal
FOOD HYDROCOLLOIDS
Volume 60, Issue -, Pages 29-37Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.foodhyd.2016.03.007
Keywords
Ovalbumin; Phosphorylation; Emulsifying properties; P-31 NMR; XPS; Mechanism
Categories
Funding
- earmarked fund for Modern Agro-industry Technology Research System [nycytx-41-g22]
- Fundamental Research Funds for the Central Universities [2662015PY080]
Ask authors/readers for more resources
In this work, ovalbumin (OVA) was phosphorylated by dry-heating at three different pH values (5.0, 7.0 and 9.0) and 45 degrees C for 12 h in the presence of sodium tripolyphosphate (STP). The results indicated that, when compared with native OVA (N-OVA), the zeta potential absolute value of phosphorylated OVA (PPOVA) increased from 2.13 mv (N-OVA) to 13.57(PP-OVA-pH5.0), 16.00(PP-OVA-pH 7.0) and 11.20 mv (PPOVA- pH 9.0); the volume-weighted mean diameter (D [4,3]) of emulsions stabilized by the N-and PPOVA decreased from 70.22 mm (N-OVA) to 37.16(PP-OVA-pH 5.0), 16.21(PP-OVA-pH 7.0) and 43.52 mm (PP-OVA-pH 9.0); and PP-OVA emulsions exhibited a more narrow monomodal size distribution and a smaller particle size than those of N-OVA, with the corresponding emulsifying activities index (EAI) increased from 92.71(N-OVA) to 142.51(PP-OVA-pH5.0), 224.88(PP-OVA-pH 7.0), and 150.97(PP-OVA-pH 9.0), respectively. The microscopic observation showed that the emulsion droplets of PP-OVA were more densely and uniformly distributed than those of N-OVA. Furthermore, characterization of PP-OVA by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and P-31 nuclear magnetic resonance (P-31 NMR) revealed that phosphate groups were bound to the-OH on serine and threonine and the-NH2 on lysine and arginine, with covalent interactions (CeOeP and C-N-P bounds) formed between OVA and STP. This study demonstrated that the introduction of phosphate groups could increase the amount of negative charge and intermolecular repulsion, decrease the particle size of droplets and improve the emulsifying ability of PP-OVA. (C) 2016 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available