Formation of nanostructured colloidosomes using electrostatic deposition of solid lipid nanoparticles onto an oil droplet interface

Nanoparticles fabricated from bulk solid lipids: Preparation, properties, and potential food applications

Unlike conventional emulsions, solid lipids are used to prepare solid lipid nanoparticles (SLNs) with crystalline structures and nanostructured lipid carriers (NLCs) with imperfect crystals or amorphous structures to encapsulate various bioactive compounds significant to food applications. The solid lipid matrix can stabilize particle structures and control release properties of the encapsulated compounds that may not be possible for emulsions with liquid droplets. In this review, common approaches of preparing SLNs and NLCs are first presented, followed by parameters used to study lipid particles, including dimensional, morphological, charge, thermal, and crystalline properties. The structures of SLNs and NLCs with respect to the release mechanisms of encapsulated compounds are discussed in the context of lipid and emulsifier chemistry and preparation conditions. Lastly, possible applications of SLNs and NLCs in food systems are discussed.

Architectural Design of Self-Assembled Hollow Superstructures

Colloidal nanoparticle assemblies are widely designed and fabricated via various building blocks to enhance their intrinsic properties and potential applications. Self-assembled hollow superstructures have been a focal point in nanotechnology for several decades and are likely to remain so for the foreseeable future. The novel properties of self-assembled hollow superstructures stem from their effective spatial utilization. As such, a comprehensive appreciation of the interactive forces at play among individual building blocks is a prerequisite for designing and managing the self-assembly process, toward the fabrication of optimal hollow nanoproducts. Herein, the emerging approaches to the fabrication of self-assembled hollow superstructures, including hard-templated, soft-templated, self-templated, and template-free methods, are classified and discussed. The corresponding reinforcement mechanisms, such as strong ligand interaction strategies and extra-capping strategies, are discussed in detail. Finally, possible future directions for the construction of multifunctional hollow superstructures with highly efficient catalytic reaction systems and an integration platform for bioapplications are discussed.

Interfacial Antioxidants: A Review of Natural and Synthetic Emulsifiers and Coemulsifiers That Can Inhibit Lipid Oxidation

There has been strong interest in developing effective strategies to inhibit lipid oxidation in emulsified food products due to the need to incorporate oxidatively labile bioactive lipids, such as ω-3 fatty acids, conjugated linoleic acids, or carotenoids. Emulsifiers or coemulsifiers can be utilized to inhibit lipid oxidation in emulsions. Both of these molecular types can adsorb to droplet surfaces and inhibit lipid oxidation, but emulsifiers can also stabilize droplets against aggregation whereas coemulsifiers cannot. There are a host of existing emulsifiers, covalent conjugates, or physical complexes that have the potential to inhibit lipid oxidation by a variety of mechanisms. Existing emulsifiers with antioxidant potential consist of surfactants, phospholipids, proteins, polysaccharides, and colloidal particles. Conjugates and complexes are typically formed by covalently or physically linking together a surface-active molecule with an antioxidant molecule. This article reviews the molecular and physicochemical basis for the surface and antioxidant activities of emulsifiers and coemulsifiers, highlights the important properties of interfacial layers that can be engineered to control lipid oxidation, and outlines different kinds of existing emulsifiers, conjugates, and complexes that can be used to inhibit oxidation.

Tailored microstructure of colloidal lipid particles for Pickering emulsions with tunable properties

Sub-micron colloidal lipid particles (CLPs) can successfully be used as Pickering stabilizers in oil-in-water (O/W) emulsions, leading to an enhanced physical stability compared to conventional emulsifier-stabilized emulsions. Varying the lipid solid-liquid ratio leads to particles with distinct nanostructure and morphology, resulting in tunable emulsion stabilization performance. Our CLPs are produced by hot high pressure homogenization of high melting point fats in water, and subsequent cooling to induce lipid crystallization. Lath-like tripalmitin and palm stearin CLPs form jammed, cohesive interfacial layers that prevent relaxation of emulsion droplets, and form a three-dimensional network in the continuous aqueous phase. CLPs consisting of a mixture of solid tripalmitin and liquid tricaprylin are polycrystalline platelet-like particles that form O/W emulsions with spherical and bridged droplets covered by a thin particle layer. Our results present a versatile approach to interfacial design that also opens up new perspectives for development of novel delivery systems for active ingredients.