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.

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Skim milk was concentrated by reverse osmosis (RO), nanofiltration (NF) and ultrafiltration (UF) and the retentates were spray‐dried. The resulting powders were reconstituted to 25% TS and sterilised to evaluate their heat stability. Reverse osmosis led to maximum retention of calcium, a fall in pH for its retentate and its reconstituted powder. All RO powders produced a weak gel on heating. Some calcium was lost during NF and a greater amount during UF. Their resulting reconstituted powders had a higher pH than those produced by RO. Powders produced by UF showed poor heat stability. Only one powder produced by NF showed good heat stability. This could be improved by addition of stabilisers at appropriate addition rates.

Mouthdrying is commonly associated with whey protein fortified products. Therefore, mitigating strategies could be key to reducing mouthdrying and maximising the benefits from such products. Currently, few studies have successfully mitigated whey protein derived mouthdrying and this paper aims to investigate different strategies to reduce mouthdrying effects. Accordingly, a series of experiments were carried out with a trained sensory panel (n = 11). Two different whey protein food matrices were tested: (a) whey protein beverages (WPB) varying in lactose (0.05–12.4% w/v) and fat (0.9–7.2% w/v) levels and (b) whey protein fortified snacks: cupcakes with differing whey protein concentrate (WPC) powders (standard and heat-stable) and scones with varying fat content (with and without cream topping). Overall results suggested the tested strategies had limited significant effects on whey protein derived mouthdrying. Increasing lactose (9.4% w/v) in WPBs and fat levels (via cream topping) on scones significantly suppressed mouthdrying. However, all other tested strategies (increasing fat in WPBs and heat-stable WPC in cupcakes) had no significant effect on suppressing perceived mouthdrying. This work demonstrates the challenges with mitigating whey protein derived mouthdrying; however, cross-modal taste suppression and increasing lubrication warrant further investigation.

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