This article reviews progress in the field of food colloids with particular emphasis on advances in novel functional ingredients and nanoscale structuring. Specific aspects of ingredient development described here are the stabilization of bubbles and foams by the protein hydrophobin, the emulsifying characteristics of Maillard-type protein-polysaccharide conjugates, the structural and functional properties of protein fibrils, and the Pickering stabilization of dispersed droplets by food-grade nanoparticles and microparticles. Building on advances in the nanoscience of biological materials, the application of structural design principles to the fabrication of edible colloids is leading to progress in the fabrication of functional dispersed systems-multilayer interfaces, multiple emulsions, and gel-like emulsions. The associated physicochemical insight is contributing to our mechanistic understanding of oral processing and textural perception of food systems and to the development of colloid-based strategies to control delivery of nutrients during food digestion within the human gastrointestinal tract.

Colloids in food: ingredients, structure, and stability

A novel method of preparing stable zein nanoparticle dispersions for encapsulation of peppermint oil

Characterization of microcapsulated β-carotene formed by complex coacervation using casein and gum tragacanth.

During the last two decades, important insights into the physico-chemical properties of oil-in-water emulsions under various food-processing conditions have been gained. Much of this research has focused on understanding how the various types of proteins, in particular milk proteins, function as emulsifiers and stabilizers in food emulsions. Recently, attention has been given to understanding the behavior of emulsions during gastrointestinal digestion, using mainly in vitro models. These studies have provided useful information on how various types of emulsions behave in a wide range of physical (e.g. shear, temperature) and biochemical (e.g. dilution, pH, pepsin, pancreatin, mucins, bile salts) environments that are relevant to digestion. This knowledge may allow manipulation of the physico-chemical and interfacial properties to modulate lipid ingestion and to improve the bioavailability of lipid-soluble nutrients. However, many of these findings will need to be validated in in vivo models and human clinical trials. Limited studies in humans have shown that the extent and the duration of postprandial lipemia are positively related to the pathogenesis and progression of coronary heart disease. The rate of digestion of lipids also appears to be important in satiation and subsequent energy regulation.

Janiene Gilliland

Papers

Temperature-dependent complexation between sodium caseinate and gum arabic

Thermal treatment to form a complex surface layer of sodium caseinate and gum arabic on oil–water interfaces

44. The need for greater understanding of delivering existing and novel food products without negative impacts on human and planetary health