title: Dairy-Based Emulsions: Viscosity Affects Fat Difference Thresholds and Sweetness Perception.
abstract: In complex emulsions, viscosity or viscosity-associated sensory attributes such as creaminess are important for quality assessment and product differentiation. Two sets of emulsions with fat or locust bean gum content being varied at seven levels were developed; the two emulsions at each level had similar apparent viscosity. Additionally, sugar concentration was kept constant either with respect to total emulsion, or with respect to the aqueous phase. Series of two-alternative forced choice tests were performed with one constant stimulus, and just noticeable differences were calculated using probability regression. The results show that, when viscosity was not compensated, it was easy for the subjects to (a) distinguish emulsions with different fat content when the fat content was addressed in the question, and to (b) distinguish emulsions with different fat or locust bean gum content when creaminess was addressed. For the latter descriptor, it is of minor importance whether viscosity is altered by fat content or a thickener. Weber fractions that were calculated for viscosity were approximately 0.20. The quantitative effects of viscosity on sweetness, however, depend on how product rheology was modified.
authors.affiliation: Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany. susann.zahn@tu-dresden.de.
authors.forename: Susann
authors.initials: S
authors.lastname: Zahn
authors.affiliation: Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany. karin.hoppert@tu-dresden.de.
authors.forename: Karin
authors.initials: K
authors.lastname: Hoppert
authors.affiliation: Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany. f-ull@web.de.
authors.forename: Franziska
authors.initials: F
authors.lastname: Ullrich
authors.affiliation: Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany. harald.rohm@tu-dresden.de.
authors.forename: Harald
authors.initials: H
authors.lastname: Rohm
keywords: difference threshold; fat; just noticeable difference (JND); model emulsion; sugar; viscosity