Consistent Effects of Whey Protein Fortification on Consumer Perception and Liking of Solid Food Matrices (Cakes and Biscuits) Regardless of Age and Saliva Flow

Abstract

Although there are numerous high protein products on the market, they are typically not designed with, or for, older consumers. This is surprising considering that dietary guidelines recognise the need for higher protein intake in later life. Protein fortified products are, however, associated with negative sensory attributes and poor consumer acceptance. This paper investigates the extent of mouthdrying sensations within a high protein solid food matrix, along with the effect of age and saliva flow. Solid models using cakes and biscuits, with or without protein fortification, were investigated. The sensory profile and physical properties were analysed and two volunteer studies (n = 84; n = 70) were carried out using two age groups (18–30; 65+). Volunteers rated individual perception and liking of products, and salivary flow rates (mL/min) were measured. Unstimulated salivary flow rates were significantly lower (p < 0.05) in older adults, although this was not found to influence product perception. Protein fortification of cakes and biscuits significantly increased (p < 0.05) perceived mouthdrying, hardness and “off” flavours, and significantly reduced (p < 0.05) melting rate, moistness and liking compared with the control versions. There is a clear need to address negative sensory attributes associated with protein fortification of cakes and biscuits to ensure product suitability for older adults.

Influence of Age and Individual Differences on Mouthfeel Perception of Whey Protein-Fortified Products: A Review

“…Commonly proposed causes of whey protein beverage (WPB) derived mouthdrying adapted from Norton et al [89] and associated limitations [135][136][137][138][139][140]. Cakes and biscuits [90], WPB [83,86,91,92,[123][124][125][126][140][141][142], rye bread and cream cheese [94] o…”

“…Provides an objective sensory measure of mouthdrying [90], muffins [93], rye bread and cream cheese [94] o…”

“…Whey protein-fortified products typically have poor consumer acceptance and this has been linked to both undesirable taste and aroma attributes, as well as negative mouthfeel attributes, such as a build-up of mouthdrying, mouthcoating, chalky, metallic and filming, associated with repeated consumption [ 81 , 83 , 84 , 85 , 86 , 87 , 88 ]. Mouthdrying has been perceived by consumers in two different whey protein-fortified food matrices [ 89 , 90 ]. For example, within a liquid model, beverages fortified with whey protein were associated with mouthdrying, low liking scores and presence of off flavours [ 83 , 89 , 91 , 92 ].…”

“…For example, within a liquid model, beverages fortified with whey protein were associated with mouthdrying, low liking scores and presence of off flavours [ 83 , 89 , 91 , 92 ]. Within a solid model, snacks (such as cakes, muffins, biscuits and rye bread) fortified with whey protein were perceived as mouthdrying and/or had a dry texture and reduced liking [ 90 , 93 , 94 ]. These studies demonstrate consumers can perceive negative sensory attributes associated with whey protein-fortified products and mitigating such attributes may be the key to promoting compliance and suitability for older adults.…”

“…The addition of WPI to sauces has been found to contribute additional flavour attributes (fishy, vegetable soup, chemical, savoury, bitter) as well as mouthfeel (grainy) [ 99 ]. Similarly, fortification of biscuits with WPI has been shown to alter appearance (roughness, density), flavour (bitter, savoury, burnt sugar, off flavours) and mouthfeel (teeth packing and slower melt rate) [ 90 , 100 ]. Cakes have also been fortified with WPI and WPC, which led to an increase in negative attributes such as mouthdrying, chewy, increased crumb size and firmness of bite [ 90 ].…”