Recombinant microgels utilized to formulate green Pickering emulsions

The fabrication of a stable food-grade Pickering emulsion (PEs) system has been challenging because of difficulties in ensuring the safety of auxiliary reagents and the compatibility of the materials. In this study, inspired by our previous experiments, we devised recombinant microgels (RMs) with a compact structure by freeze–thaw cycles (FTCs) method, which was used to fabricate a green food-grade PE system. The application of FTCs demonstrated an enhancement of RMs in the crystallinity, surface wettability, and textural properties. Specifically, RMs subjected to 3 FTCs had a compact cube structure (0.6–1.1 μm), near neutral surface wettability (89.95°), and an amorphous crystallinity (55.93%), which may be attributed to the decrease of free water content and the formation of hydrogen bonds. A concentration of 0.5% RMs was used to stabilize PEs, which showed a uniform microscopic distribution and a particle size of 13.87 μm. It was found that when the concentration of the external phase exceeded 0.5% stable oil-in-water emulsions formed. Otherwise, multiple emulsions formed. This study underscores the viability of using RMs to construct green food-grade PE systems.