Natural biopolymer-stabilized Pickering emulsions are being explored as alternatives to surfactant-stabilized emulsions in food applications. This work explores the long-term stability degradation of oil-in-water (O/W) Pickering emulsions stabilized by whey protein isolate (WPI) and chitosan (CS), using optical tweezers to evaluate their potential for reduced-fat mayonnaise. The study found that for O/W emulsions prepared with a 50% water phase volume fraction, the maximum contact force of the droplets decreased from 69 to 37 pN, while the depletion force (DF) increased from 2.23 to 5.94 pN by Day 45. On Day 60, contact coalescence was observed. The application of this emulsion in mayonnaise preparation revealed that its mechanical stability and resistance to destabilization were superior to those of traditional mayonnaise. This study provides experimental references for a deeper understanding of emulsion stability mechanisms.
Tonghua Hu,Peng Zhao,Yuanyuan Li,Nyachieo Kennedy Momanyi,Xingyu Liu,Jianyu Sun,Yong Xie,Limin Liu
Binary assembly of nanoparticles with different shapes, sizes, and materials yields novel structures with geometric diversity. Through meticulous control of the assembly structure, it is possible to engineer specific types of inter-building block interactions, such as plasmonic, electronic, and magnetic coupling, which are crucial for tailoring the material's overall functionality. However, achieving control over the structural symmetry of these assemblies and exploring the potential regulatory mechanisms, including the orientational alignment of non-spherical nanoparticles, remains a challenge. Here, gold nanorods (GNRs, length ≈ 62 nm, diameter ≈ 17 nm) and octahedral nickel ferrite nanocrystals (∼17 nm) were used as building blocks, by regulating the weak interactions between the nanoparticles, the regulatory mechanism of the binary assemblies was explored. High concentration nickel ferrites modified with polyethylene glycol (PEG) tended to contact substrate in a plane-to-substrate manner to ensure structural stability, and further formed planar stripe-shaped structures. Droplet evaporation assembly experiments showed that with PEG serving as the depletant, the combined effects of depletion and entropy patchiness led to end-to-end assembly of GNRs at the periphery of the stripes, instead of a more stable side-by-side arrangement. Furthermore, through the interfacial assembly method, the anchoring effects of GNRs at the edge of nickel ferrites were further mediated. Comparative experiments on GNR assembly with and without depletants showed that incorporating oleic acid and dodecanethiol enhanced the depletion and van der Waals attraction between oil-soluble GNRs, resulting in side-by-side assembly at the periphery of nickel ferrite superlattices. This work has demonstrated a strategy for effectively controlling multi-component assembly, promoting the development of complex nanoscale superstructures with potential applications in optical/plasmonic devices, bimetallic heterojunctions, and heterogeneous catalysts.
危险品化学品经营许可证（带存储）