Purification of phosvitin phosphopeptides using macro-mesoporous TiO2
Macro-mesostructured titanium dioxide (MMTD) was synthesized, characterized and applied as an adsorbent in the purification of phosvitin phosphopeptides (PPPs) from egg-yolk protein hydrolysates successfully. The synthesized material was analyzed using Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption–desorption analysis and scanning electron microscopy (SEM). The resultant MMTD exhibited a uniform macroporous structure with worm-like mesoporous walls, and the particle sizes were around 22 μm with the facility to be separated from aqueous solution. In the purification process, the adsorption of PPPs onto MMTD fitted well with the Freundlich model and pseudo-second-order kinetics model, and the maximum adsorption capacity reached 36.47 mg g−1 in 20 min when the crude polypeptide concentration was 16 mg mL−1. The purity of the obtained PPPs was relatively high with a nitrogen/phosphorus molar ratio (N/P) of 5.4. Moreover, the reusability of MMTD was satisfying in the twenty repeated adsorption–desorption cycles. Hence, the purification of PPPs using MMTD was highly efficient and could be scaled-up for practical application.