Fabrication of cross-linked β-lactoglobulin nanoparticles as effective stabilizers for Pickering high internal phase emulsions

To develop the effective utilization of beta-lactoglobulin in Pickering high internal phase emulsions (HIPEs), the food-grade beta-lactoglobulin nanoparticles (BLGNPs) as emulsion stabilizers were designed and fabricated by using ethanol as a desolvation solvent and genipin (GP) as a crosslinking agent. The influence of processing sequence including ethanol desolvation, pH adjustment and GP crosslinking on the properties of BLGNPs were investigated. The results indicated that BLGNPs obtained by GP crosslinking after desolvation and pH adjustment had the largest size (373.67 +/- 15.71 nm), a larger contact angle (83.5 degrees), and the best thermal and storage stabilities. The BLGNPs stabilized Pickering HIPEs exhibited a good thermal stability due to the continuation of GP crosslinking during heating treatment. The increase of ionic strengths in emulsion systems resulted in an increased apparent viscosity and moduli of the emulsion, attributing to the formation of a stable emulsion crosslinked network. Moreover, the emulsions showed an excellent freeze-thaw stability when ionic strength exceeded 50 mM, indicating the possibility of long-term cryopreservation. This study successfully fabricated novel BLGNPs and its stabilized emulsions, and the results could promote the effective application of BLGNPs in Pickering HIPEs.