title: Influence of double (w1/o/w2) emulsion composition on lubrication properties.
abstract: Double (w1/o/w2) emulsions are potential fat replacers in foods. Fats are known for their lubricating properties, which contribute to texture perception. It is therefore of interest to understand how the composition of double emulsions influences lubrication properties. This study focuses on the understanding of the influence of the fraction of inner dispersed aqueous phase w1and the gelation of the w1droplets on the lubrication properties of double emulsions. The addition of an inner water phase w1to the oil droplets decreased friction at low entrainment speeds due to adsorption of the lipophilic emulsifier polyglycerol polyricinoleate (PGPR) at the hydrophobic tribo-surface. At higher entrainment speeds, double emulsions with w1fractions of up to 6% (corresponding to fat reduction of 20%) displayed comparable tribological behavior as full-fat single (o/w2) emulsions. For double emulsions with gelled w1droplets at higher w1fractions of up to 15% (corresponding to fat reduction of 50%), an increase in friction was observed compared to full-fat single (o/w2) emulsions. The increase in friction is probably related to the presence of gelled droplets expelled from the inner w1into the outer w2phase, and to the deformability of (w1/o) droplets. Lubrication decreased when gelled particles were expelled from the inner w1phase to the outer w2phase. Lubrication also decreased when the deformability of (w1/o) droplets decreased, since less deformable (w1/o) droplets spread less easily on the tribo-pair surface. Knowledge about lubrication properties of double emulsions can be used in future studies to relate composition to sensory perception and develop double emulsions further as fat replacers.
authors.affiliation: Division of Human Nutrition, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands and Physics and Physical Chemistry of Foods, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands. elke.scholten@wur.nl.
authors.forename: A K L
authors.identifier: http://orcid.org/0000-0003-0542-3451
authors.initials: AK
authors.lastname: Oppermann
authors.affiliation: Physics and Physical Chemistry of Foods, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands. elke.scholten@wur.nl.
authors.forename: L C
authors.initials: LC
authors.lastname: Verkaaik
authors.affiliation: Division of Human Nutrition, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Stieger
authors.affiliation: Physics and Physical Chemistry of Foods, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands. elke.scholten@wur.nl.
authors.forename: E
authors.initials: E
authors.lastname: Scholten
mesh_terms: D004655:Emulsions / Q000737:chemistry* / Q000378:metabolism; D019358:Fat Substitutes / Q000737:chemistry* / Q000378:metabolism; D005223:Fats / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008153:Lubrication; D014867:Water / Q000737:chemistry*
chemical_list: D004655:Emulsions; D019358:Fat Substitutes; D005223:Fats; D014867:Water