Understanding mechanisms behind the oily mouthcoating perception of pure vegetable oils using tribology

• Published in: Journal of texture studies Vol. 55; no. 2; pp. e12829 - n/a
• Main Authors: Tecuanhuey, Maria, Girardi, Alicia, Corrà, Lucia, Busom Descarrega, Josep, Sagalowicz, Laurent, Devezeaux de Lavergne, Marine
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.04.2024
• Subjects: ball‐bearing lubrication; edible oil; fat crystals; Food; Lubrication; oily mouthcoating; Perception; Plant Oils; sensory; tribology; Viscosity; fat crystals; sensory; tribology; edible oil; oily mouthcoating; ball‐bearing lubrication
• ISSN: 0022-4901; 1745-4603
• DOI: 10.1111/jtxs.12829

Tribology is the science of measuring friction between surfaces. While it has been widely used to investigate texture sensations of food applications, it is seldom applied in pure edible oil systems. In this research, we measured friction, viscosity, and solid fat content (SFC) of nine vegetable oils at 30 and 60°C. Polarized static microscopy was used to assess crystal formation between 60 and 30°C. Descriptive sensory analysis and quantification of oral oil coatings were performed on the oils at 60°C. Expressing the friction factor of oil over the Hersey number (calculated using high sheer‐viscosity values) showed no differences in friction between 30 and 60°C, except for shea stearin. Static microscopy revealed crystallization occurred at 30°C for shea stearin, whereas no or few crystals were present for other oils. At 30°C, friction at 1 × 10−2 m/s showed an inverse correlation with SFC (R = −0.95) and with high shear rate viscosity (R = −0.84), as well as an inverse correlation (R = −0.73) with “oily mouthcoating” perception. These results suggest that friction could be a predictor of fat‐related perceptions of simple oil systems. Additionally, we hypothesize that the presence of crystals in oils could lower friction via a ball‐bearing lubrication mechanism. This research suggests that friction is a good predictor of the “oily mouthcoating” perception of edible oils. Moreover, it is hypothesized that the presence of small rounded crystals close to mouth temperature in shea stearin could result in a ball‐bearing mechanism decreasing in mouth friction.