Enhanced Protein Adsorption Capacity of Macroporous Pectin Particles with High Specific Surface Area and an Interconnected Pore Network

There has been much interest in developing protein adsorbents using nanostructured particles, which can be engineered porous materials with fine control of the surface and pore structures. A significant challenge in designing porous adsorbents is the high percentage of available binding sites in the pores owing to their large surface areas and interconnected pore networks. In this study, continuing the idea of using porous materials derived from natural polymers toward the goal of sustainable development, porous pectin particles are reported. The template-assisted spray drying method using calcium carbonate (CaCO3) as a template for pore formation was applied to prepare porous pectin particles. The specific surface area was controlled from 177.0 to 222.3 m2 g–1 by adjusting the CaCO3 concentration. In addition, the effects of a macroporous structure, the specific surface area, and an interconnected pore network on the protein (lysozyme) adsorption capacity and adsorption mechanism were investigated. All porous pectin particles performed rapid adsorption (∼65% total capacity within 5 min) and high adsorption capacity, increasing from 1543 to the highest value of 2621 mg g–1. The results are attributed to the high percentage of available binding sites located in the macropores owing to their large surface areas and interconnected pore networks. The macroporous particles obtained in this study showed a higher adsorption capacity (2621 mg g–1) for lysozyme than other adsorbents. Moreover, the rapid uptake and high performance of this material show its potential as an advanced adsorbent for various macromolecules in the food and pharmaceutical fields.