Pickering emulsions stabilized by homogenized ball-milled eggshell particles in combination with sodium alginate.

Eggshells, by-products of egg processing, were ball-milled and homogenized into particles (eggshell particles, ESPs) and then were used as the stabilizer with a two-step oil addition method to produce Pickering emulsions. Meanwhile, sodium alginate (SA) was used to modify the emulsifying ability of ESPs. The results indicated that SA addition helped to improve the dispersion performance and increase the negative charge of ESPs. Pickering emulsions stabilized by ESPs/SA showed much smaller particle size than those stabilized by ESPs. The maximum oil fraction in the ESPs/SA-stabilized emulsions reached up to 0.8, while that was only 0.75 in ESPs-stabilized emulsions. The presence of SA significantly enhanced the freeze-thaw, thermal, dilution, and centrifuge stability of ESPs-stabilized Pickering emulsions. The findings demonstrate the potential of eggshell particles as a kind of natural Pickering stabilizer, which will increase the high value-added utilization of poultry egg industry by-products.

Structural modification of whey protein isolate by cinnamaldehyde and stabilization effect on ß-carotene-loaded emulsions and emulsion gels.

The effect of cinnamaldehyde (CA) on the structure and properties of whey protein isolate (WPI) was investigated. The resultant WPI/CA complex was used as stabilizer to form emulsions and emulsion gels, which were used for the delivery and protection of ß-carotene. The particle size and hydrophobicity of WPI solution increased and then decreased with the addition of CA. Circular dichroism showed that CA mainly changed the secondary structure of WPI, with increasing ß-fold content from 47.2% to 72.9%. The fluorescence spectra showed that both tryptophan and tyrosine in WPI were involved in the interaction with CA. WPI/CA complex as the stabilizer could form the stable emulsions and emulsion gels, which showed better protection effect on ß-carotene, and helped enhance its bioaccessibility. The knowledge provides insights into the development of new multifunctional food ingredients and the enhancement of protein modification in food system.

Controllable Viscoelastic Properties of Whey Protein-Based Emulsion Gels by Combined Cross-Linking with Calcium Ions and Cinnamaldehyde.

Whey protein-based emulsion gels were fabricated by combined covalent cross-linking with cinnamaldehyde and ionic cross-linking with calcium ions. The structural and rheological properties of these emulsion gels were characterized by microscopy, macrorheometry, and microrheometry. Soft to hard emulsion gels could be fabricated by altering the Ca2+ level. However, water separation occurred in the emulsion gels at high calcium levels, indicating that an appropriate balance of protein cross-linking was essential for a good functional performance of the emulsion gels. At a constant calcium ion level, cross-linking with cinnamaldehyde softened the texture of the emulsion gels and reduced the level of water separation. Thermal treatment could be used to strengthen the interaction between the whey proteins and calcium ions, presumably due to protein unfolding and aggregation. Rheology demonstrated that cross-linking reactions occurred between the whey protein and cinnamaldehyde at the oil-water interface, which decreased the viscosity of the emulsion gels, but increased their viscoelasticity. Microstructural changes observed by fluorescence microscopy were in agreement with the rheology results. Scanning electronic microscopy showed that the microstructure of the emulsion gels was strongly impacted by the presence of cinnamaldehyde, which led to a more uniform and smaller pore size. The gastrointestinal fate of the emulsion gels was determined using a simulated gastrointestinal tract model. The oral and gastric processing of the emulsion gels was strongly influenced by cinnamaldehyde cross-linking, with less aggregation being observed. The information obtained in this study may facilitate the development of more innovative protein-based products with novel functional attributes for use in foods and other applications.

Annexin A1 can inhibit the in vitro invasive ability of nasopharyngeal carcinoma cells possibly through Annexin A1/S100A9/Vimentin interaction.

Annexin A1 is a member of a large superfamily of glucocorticoid-regulated, calcium- and phospholipid-binding proteins. Our previous studies have shown that the abnormal expression of Annexin A1 is related to the occurrence and development of nasopharyngeal carcinoma (NPC). To understand the roles of Annexin A1 in the tumorigenesis of NPC, targeted proteomic analysis was performed on Annexin A1-associated proteins from NPC cells. We identified 436 proteins associated with Annexin A1, as well as two Annexin A1-interacted key proteins, S100A9 and Vimentin, which were confirmed by co-immunoprecipitation. Gene function classification revealed that the Annexin A1-associated proteins can be grouped into 21 clusters based on their molecular functions. Protein-protein interaction analysis indicated that Annexin A1 /S100A9/Vimentin interactions may be involved in the invasion and metastasis of NPC because they can form complexes in NPC cells. The down-regulation of Annexin A1 in NPC may lead to the overexpression of S100A9/Vimentin, which may increase the possibility of the invasion ability of NPC cells by adjusting the function of cytoskeleton proteins. Results suggested that the biological functions of Annexin A1 in NPC were diverse, and that Annexin A1 can inhibit the in vitro invasive ability of NPC cells through Annexin A1 /S100A9/Vimentin interaction.