Determination of human oral carbohydrate taste function and its association with food consumption and Body Mass Index (BMI)

Participants will be required to visit the Centre of Advanced Sensory Science laboratory, Deakin University for at least 17 times (maximum of 7 times per types of carbohydrate). Participants may experience: Visit 1: Food consumption and anthropometry. Participants will be asked to complete a Cancer Council food frequency questionnaire, a 4-day diet diary, and a 3-factor eating questionnaire at home within 1 month of the sensory tests. Height, weight, waist circumference will be measured at baseline. Weight and waist circumference will be measured again at the end (final session). Visits 1-2: Determination of taste thresholds for the five basic tastes. Participants will be presented with a series of eight solutions for each tastants (sweet, sour, bitter, salty and umami), which will be arranged in ascending order of concentration. Participants will be asked to sample each solution, expel it after 10 seconds and then describe the taste of the solution. The process will be repeated twice (for visit 1-2) and will take approximately 1 hour 30 minutes for each visit. Visits 3: Suprathreshold (sufficient strength or quantity to produce a perceptible physiological effect) taste intensity perception for the five basic tastes. Subjects will be given a brief training session in the use of gLMS (General Labelled Magnitude Scale) (in ascending order). gLMS is a scale consists of a vertical line, used to measure perceived taste intensity. To test for intensity perception of the five basic tastes (bitter, salty, sweet, sour, umami), participants will be presented with numbered trays that contained 4 randomized solution for each taste quality (15mL each). Participants were instructed to held in each of the solutions in the mouth for at least five seconds and expectorate. Participants were then required to rate the taste intensity perception on a computerised gLMS. Participants were also instructed to rinse their mouth for five seconds with filtered deionised water between samples. Solutions will be presented in randomised order. The minimum and maximum concentrations of solutions will range from 0.04g/L-63.1g/L This will be repeated twice (for visit 3). Visit 3 will take about 50 minutes, depending on their taste sensitivity. Visits 4-10; 11-17: Detection thresholds for maltodextrin and inulin. Each participant will be blinded (they will not know which carbohydrate they are tasting). Detection thresholds for carbohydrates (maltodextrin, inulin) will be tested using ascending triangle forced-choice procedure. Participants will be provided with three 25 mL samples: two controls (filtered deionised water solutions) and one containing carbohydrate (maltodextrin or inulin), per set, in ascending order from the lowest to the highest concentration. Participants were instructed to rinse their mouths for five seconds with filtered deionised water before beginning the task and between each sample set. Detection thresholds for each sweetener or polysaccharides was defined as the concentration of carbohydrate required for a participant to correctly identify the sweetened or polysaccharide sample as ‘odd’ from the two control samples, in three consecutive sample sets at one concentration level (Meilgaard et al., 2007). Each visit will take about 10-20 minutes, depending on the sensitivity of the individual. Each session will be separated by a minimum of 1 hour. The minimum and maximum concentration of solutions will range from 0.04g/l-63.1g/L