Distinct Temporal Mouthfeel in Dairy and Plant-Based Milk Is Related to Their Rheological and Tribological Spectra

Despite an expanding market for plant-based milks (PBMs), replicating the techno-functional properties of fluid dairy in PBMs remains challenging due to limited understanding of how the fluid physics of the beverage relate to their mouthfeel and hedonic responses. This study investigated the microstructure, tribological, and rheological (extensional and shear viscosity) profiles of PBMs (soy, almond, oat) and dairy milks (whole, skim, heavy cream), in relation to their sensory mouthfeel, assessed by consumers (n = 86) using Temporal check-all-that-apply (TCATA) and attribute intensity ratings. Whole milk, almond, and heavy cream were shear-thinning, with heavy cream exhibiting viscoelasticity during stretching and oat, soy, and fat-free were Newtonian (or near-Newtownian). Based on TCATA profiles analysis and Cochrane's Q Test (with McNemer test as post hoc) (p ≤ 0.05) and on Multiple Factor Analysis (MFA), PBMs were characterized as thin and astringent, whereas heavy cream and whole milk were thick and creamy. Whole milk had a low frictional coefficient (CoF), optimal viscosity, smoothness, and creaminess sensory attributes, while soy, oat, and almond milks were associated with thin, watery, and astringent sensory properties and high CoF. This study establishes important associations linking temporal mouthfeel perception with multi-rheological measures and tribology in PBMs and dairy milks. Understanding the basis for differences in the mechano-structural and sensory profiles can help optimize PBMs' mouthfeel for improved consumer acceptance.