Microgel Particles at Interfaces: Phenomena, Principles, and Opportunities in Food Sciences

Self-Assembled Egg Yolk Peptide Micellar Nanoparticles as a Versatile Emulsifier for Food-Grade Oil-in-Water Pickering Nanoemulsions

Pickering emulsions stabilized by food-grade particles have garnered increasing interest in recent years due to their promising applications in biorelated fields such as foods, cosmetics, and drug delivery. However, it remains a big challenge to formulate nanoscale Pickering emulsions from these edible particles. Herein we show that a new Pickering nanoemulsion that is stable, monodisperse, and controllable can be produced by employing the spherical micellar nanoparticles (EYPNs), self-assembled from the food-derived, amphiphilic egg yolk peptides, as an edible particulate emulsifier. As natural peptide-based nanoparticles, the EYPNs have a small particle size, intermediate wettability, high surface activity, and deformability at the interface, which enable the formation of stable Pickering nanodroplets with a mean dynamic light scattering diameter below 200 nm and a polydispersity index below 0.2. This nanoparticle system is versatile for different oil phases with various polarities and demonstrates the easy control of nanodroplet size through tuning the microfluidization conditions or the ratio of EYPNs to oil phase. These food-grade Pickering nanoemulsions, obtained when the internal phase is an edible vegetable oil, have superior stability during long-term storage and spray-drying based on the irreversible and compact adsorption of intact EYPNs at the nanodroplet surface. This is the first finding of a natural edible nano-Pickering emulsifier that can be used solely to make stable food Pickering nanoemulsions with the qualities of simplicity, versatility, low cost, and the possibility of controllable and mass production, which make them viable for many sustainable applications.

Natural Rice Starch Granules for Green Cleaning

Detergents are steadily becoming one of the necessities in our daily life. However, synthetic detergents are threatening the global environment and human health, as most of them are derived from petrochemicals. Inspired by one of the ancient Asian traditions that the rice-washing water served as a natural detergent for bathing and washing, this work provides insights into the mechanism of the detergent effect of rice-washing water. It is proposed that starch granules existing in the rice-washing water are interfacially active, which can facilitate the formation of O/W Pickering emulsions. This principle is successfully extended to rice flour that is made by mechanical media milling in a large scale. Pickering emulsions loading different organic solvents as dispersed phase can be stabilized by these food-grade granules without adding other chemical additives. Practical trails of removing pesticide residues and meat cleaning confirm the possibilities to render these natural rice starch granules as sustainable detergents for food cleaning with high safety assurance.

Recent Progress of Polysaccharide‐Based Hydrogel Interfaces for Wound Healing and Tissue Engineering

Polysaccharide is an abundant and reproducible natural material that is biocompatible and biodegradable. Polysaccharide and its derivatives also possess distinctive properties such as hydrophilicity, mechanical stability, as well as tunable functionality. Polysaccharide‐based hydrogels can be constructed via the physical and/or chemical crosslinking of polysaccharide derivatives with different functional molecules, as porous network structures or nanofibrillar structures. This review discusses the biomedical applications of polysaccharide‐based hydrogels containing native polysaccharides, polysaccharide derivatives, and polysaccharide‐composite hydrogels. Recent works on the fabrication, physical properties, advanced engineering, biomedical applications of cellulose‐, chitosan‐, alginate‐, and starch‐based hydrogels are also elaborated. Such porous swelling scaffolds exhibit great advantages at the interface of a negative pressure system such as wound dressing. In addition, the authors also discuss and summarize the exemplary research works of these hydrogels in the applications of drug release, wound dressing, and tissue engineering. Finally, challenges and future perspectives about the development of polysaccharide‐based hydrogels are discussed.