Investigation of the Perception of Protein Fortified Foods and Beverages

This study aims to investigate whether protein fortification of foods and beverages causes mouthdrying and mucoadhesion and whether this is influenced by age and saliva flow.

To investigate, by using protein fortified foods and beverages, whether mucoadhesion to the oral cavity is greater for older adults compared to younger adults and determine whether it is related to salivary flow rate. To determine whether protein fortification of foods and beverages causes mouthdrying and whether perception and acceptance are influenced by age and individual differences in saliva flow. These aims will be investigated using two different models: a liquid model using whey protein and a solid model using protein fortified biscuits and cakes.

This study involves both a crossover design where each participant tastes both the control product (not fortified) and the protein fortified product with an appropriate break between the two sessions. It is also both a within and between groups design as the responses from the older participants will be compared to the younger participants. The study will be conducted single blind as it not feasible to blind the researcher. Each participant will attend 3 study visits and all foods will be presented with random blinding codes.

Cake -Control Vanilla Cake and Protein Fortified Vanilla Cake Biscuit -Control Lemon Biscuit and Protein Fortified Lemon Biscuit

Whey Protein Beverages Native sample (protein unheated) Denatured whey protein (protein heated to denature)

Cake and biscuit will be used, with the amount of protein varied to study the effect on perception of the products (using sensory methods of rating drying and discrimination tests "which is the stronger in drying")

Intervention Description: To study the effect of protein denaturation on perception of whey protein beverages using sensory methods (rating drying as well as discrimination tests "which is the stronger in drying"). Measuring mucoadhesion via protein content remaining in saliva following swallowing of whey protein beverages.

Participants drink whey protein beverages (unheated and heated protein) then after different time points post swallowing (15 seconds to 5 minutes) expectorated saliva is collected to analyse protein for the extent of mucoadhesion)

Saliva collection at 4 timepoints post swallowing of each sample (15s, 30s, 60s, 120s) at study visits two and three, reported at 1 year.

Perceived mouth drying from protein fortified vanilla cake and control vanilla cake using data from sensory methods (rating drying as well as discrimination tests "which is the stronger in drying")

Perceived mouth drying from protein fortified lemon biscuits and control lemon biscuit using data from sensory methods (rating drying as well as discrimination tests "which is the stronger in drying")

Perceived mouth drying from whey protein beverages (unheated and heated whey protein) using data from sensory methods (rating drying as well as discrimination tests "which is the stronger in drying")

Reported at 1 year (Unstimulated saliva flow taken at the start of every study visit. Stimulated saliva flow taken at the start of study visit one.)

Dental status and mouth behaviour categorisation via a questionnaire. Category data (ie participants check boxes that apply). The dental status questionnaire is adapted from the WHO oral health questionnaire, it indicates where a participant has poor dental status. The mouth behaviour questionnaire is a validated questionnaire (JMBM, trademarked), we are investigating whether it relates to perception of protein fortified foods.

Inclusion Criteria: Age 18-30 years or over 65 years Self reported as healthy (no specific disease states) Exclusion Criteria: Cognitively impaired Allergies or intolerances that include coeliac disease, lactose or gluten intolerance Diabetic Had oral surgery Had stroke Smoker

No personal identification data will be shared. The study is not under an obligation to share data, however it is possible that some of the individual (unliked / non identifiable) data will be useful in a meta analysis and, hence sharing individual participant data (IPD) will be considered.

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