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.

Fat Perception: How Sensitive are We?

“…This confirms what Zahn et al . () suggested. When viscosities differ between samples tasted, the JND is lower than for isoviscous samples.…”

Just Noticeable Differences and Weber Fraction of Oral Thickness Perception of Model Beverages

“…A recent study reported JNDs for creaminess perception when the apparent viscosity of dairy‐based emulsions varied. Apparent viscosity variations were achieved by differing fat content or locust bean gum content in emulsions (Zahn and others ). Calculated Weber fractions were approximately K = 0.20 (Zahn and others ).…”

“…Apparent viscosity variations were achieved by differing fat content or locust bean gum content in emulsions (Zahn and others ). Calculated Weber fractions were approximately K = 0.20 (Zahn and others ). Rohm and Raaber () studied the JNDs and Weber fraction for kinesthetic firmness perception and spreadability perception of edible fats by asking subjects to cut and spread different spreads with a knife (Rohm and Raaber ).…”

Does milk matter: Is children’s intake affected by the type or amount of milk served at a meal?

“…This suggests that higher-ED milk promotes greater satiety than lower-ED milk. Even though the higher-ED and lower-ED milks were not rated differently in liking and preference, the children may have responded to differences in sensory properties such as viscosity or creaminess (Bakke, Shehan, & Hayes, 2016; Zahn, Hoppert, Ullrich, & Rohm, 2013), which have been shown to influence satiety and fullness (Mattes & Rothacker, 2001; Zijlstra, Mars, de Wijk, Westerterp-Plantenga, & de Graaf, 2008, Camps, et al, 2016). Sensory characteristics may play a more critical role in studies of satiation, such as the present one, than in studies of satiety (Camps, et al, 2016).…”