title: Whey protein mouth drying influenced by thermal denaturation.
abstract: Whey proteins are becoming an increasingly popular functional food ingredient. There are, however, sensory properties associated with whey protein beverages that may hinder the consumption of quantities sufficient to gain the desired nutritional benefits. One such property is mouth drying. The influence of protein structure on the mouthfeel properties of milk proteins has been previously reported. This paper investigates the effect of thermal denaturation of whey proteins on physicochemical properties (viscosity, particle size, zeta-potential, pH), and relates this to the observed sensory properties measured by qualitative descriptive analysis and sequential profiling. Mouthcoating, drying and chalky attributes built up over repeated consumption, with higher intensities for samples subjected to longer heating times (p< 0.05). Viscosity, pH, and zeta-potential were found to be similar for all samples, however particle size increased with longer heating times. As the pH of all samples was close to neutral, this implies that neither the precipitation of whey proteins at low pH, nor their acidity, as reported in previous literature, can be the drying mechanisms in this case. The increase in mouth drying with increased heating time suggests that protein denaturation is a contributing factor and a possible mucoadhesive mechanism is discussed.
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, Berks RG6 6AD, United Kingdom.
authors.forename: Stephanie P
authors.initials: SP
authors.lastname: Bull
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, Berks RG6 6AD, United Kingdom.
authors.forename: Yuchun
authors.initials: Y
authors.lastname: Hong
authors.affiliation: Department of Pharmacy, University of Reading, Whiteknights, Reading, Berks RG6 6AD, United Kingdom.
authors.forename: Vitaliy V
authors.initials: VV
authors.lastname: Khutoryanskiy
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, Berks RG6 6AD, United Kingdom.
authors.forename: Jane K
authors.initials: JK
authors.lastname: Parker
authors.affiliation: Volac International Ltd, 50 Fishers Lane, Orwell, Royston, Hertfordshire SG8 5QX, United Kingdom.
authors.forename: Marianthi
authors.initials: M
authors.lastname: Faka
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, Berks RG6 6AD, United Kingdom.
authors.forename: Lisa
authors.initials: L
authors.lastname: Methven
keywords: ANOVA, analysis of variance; DLS, dynamic light scattering; Denaturation; Drying; Mucoadhesion; Particle size; QDA, quantitative descriptive analysis; RM-ANOVA, repeated measures analysis of variance; Sequential profiling; WPC, whey protein concentrate; Whey protein; β-LG, β-lactoglobulin