Double Emulsions Relevant to Food Systems: Preparation, Stability, and Applications

Abstract

This review describes advances in the preparation of food-relevant double emulsions (DEs) of the waterin-oil-in-water (W/O/W) and oil-in-water-in-oil (O/W/O) types with emphasis on research published within the last decade. The information is assembled and critically evaluated according to the following aspects: the food application area, the range of encapsulated components and emulsion composition, the emulsification preparation methods, the balancing of the osmotic pressure, the stabilization by increased viscosity or gelation, the role of protein-polysaccharide interactions, and the techniques used to estimate DE yield and emulsification efficiency. Particular focus is directed toward the control of encapsulation and release behavior, including strategies that have been employed to improve the retention ability of the inner phase droplets by modifying the outer oil-water interface through mixed ingredient interactions, Pickering stabilization by particles, and biopolymer gelation. We also briefly consider the incorporation of DEs into dried microcapsules and the stability of W/O/W emulsions during eating and digestion. It would appear that 2 outstanding issues are currently preventing full realization of the potential of DEs in food applications: (i) the lack of availability of large-scale production equipment to ensure efficient nondestructive 2nd-stage emulsification, and (ii) the limited range of food-grade ingredients available to successfully replace polyglycerol polyricinoleate as the primary emulsifier in W/O/W formulations.

Water-in-Oil-in-Water (W/O/W) Double Emulsion Morphology and Its Degradation on Instant Noodle Seasoning

“…Muschiolik & Dickinson, 2017 show previous researches on the application of double emulsion in liquid food products such as mayonnaise or low calorie cream (Matsumoto and Kohda, 1979), low fat salad dressing and spread margarine (Gaonkar, 1994), milk fat substitution in cheese (Lobato-Calleros et al 2006) and dry food products such as film and powder coating. Research on W/O/W double emulsion application in instant noodle seasoning hasn't been performed in earlier studies, however, research on W/O/W double emulsion application in dressing performed by Taki et al (2007) has produced a patent.…”

W/O/W Multiple Emulsions as the Functional Component of Dairy Products

“…Ceramic membranes enable higher fluxes from 50 to 250 dm 3 m −2 h −1 but these values depend on porosity and pores. Some devices are designed more progressively and enable an emulsification process based on a rotating or oscillating membrane , , , .…”

Fat crystals: A tool to inhibit molecular transport in W/O/W double emulsions

“…Thanks to this typical structure, W/O/W double emulsions are a promising technology for encapsulation applications of water soluble active agents. As a further consequence, W/O/W emulsions gain increasing interest in the pharmaceutical and food industry . Long‐term retention of the entrapped compounds in the internal water droplets is hereby a key parameter.…”

“…Next to diffusion of single molecules, diffusion‐mediated transport has been described in literature . Four assisted transport mechanisms have been defined in case of water transport, that is, transport through spontaneous emulsification, reversed micelles, thinned lamellae, and hydrated surfactants . Most of the studies regarding quantification of the (water) transport kinetics illustrate the importance of the W/O/W formulation and focus mainly on osmotic regulation, emulsifier characteristics and concentrations, or on the physical state of matter of the internal water droplets (e.g., gelation of the internal water).…”