Rationale: The world-wide rising obesity rates are a major health problem. Therefore, people should moderate food intake. A lower eating rate will decrease the energy intake. The eating rate of foods can be modified by changing the texture without affecting their acceptability. Harder, chunkier, more viscous, and more voluminous foods will decrease the eating rate and thus energy intake. Bread is a staple food and contributes to a major part of the Dutch diet. By changing the proofing time and by applying vacuum cooling during the baking process, the texture of bread can be modified. The effect of this texture modification on eating rate is not investigated until now. To get an understanding of the relations between food texture and eating rate, modelling based on instrumental measurements is a promising technique as it can give valuable insights without sensorial and laboratorial labour and costs. However, it is not known if such a model can predict the eating rate as well as a model based on sensory measurements. Therefore, this study will investigate whether modelling of sensory or instrumental data predicts the eating rate of bread most accurate and can be applied for the product development of bread with modified eating rate.

Objective: The aim of the BOP-study is to compare mathematical models based on sensory or instrumental texture that predict the eating rate of bread and to validate if the models can be applied for the product development of bread with a modified eating rate by changing the proofing time and applying vacuum cooling.

Study design: The study consists out of a sensory study, instrumental measurements, and mathematical modelling. The sensory study is a randomised crossover trial. All participants consume all bread samples in a randomized order divided over four sessions. Every session will be video recorded.

Study population: Healthy Dutch adults (n=34) between 18-55 years old, and a BMI between 18.5-30 kg/m2 will be included.

Intervention: In the sensory study, participants will attend four test sessions during lunch in which sixteen bread samples will be investigated. Ten breads are commercially available and six breads are produced for product development purposes and differ in proofing time and vacuum cooling. In each session, a fixed portion of bread will be consumed by the participants during which the eating rate and sensory properties will be measured. Additionally, participants will chew and expectorate a bite-size piece of bread in replicate to determine the saliva addition to the bolus at time of swallowing.

Main study parameters/endpoints: The main study outcome is the eating rate (g/min).

Inclusion Criteria:

• Good general health and appetite (self-report)
• Between 18-55 years old at the day of inclusion
• Dutch
• BMI 18.5-30 kg/m2 (self-report)
• Regular consumer of bread

Exclusion Criteria:

• Smoking
• Following a vegan diet
• Allergies or intolerance to any ingredient of the test meals
• Suffering from diabetes
• Having taste or smell disorders (self-report)
• Difficulties with swallowing, chewing and/or eating in general
• Use of medication that may influence study outcomes (self-report)
• Pregnant or lactating women
• Braces (not including a dental wire) or oral piercing
• Consuming on average more than 21 glasses of alcohol per week
• Not willing to stop using drugs during the study period (from inclusion till last test session)
• Men having facial hair such as a beard as facial movements cannot be analysed
• Signed up for participating in another research study
• Employee of Human Nutrition department of Wageningen University
• Employee, thesis student or intern at the chair group of Sensory Science and Eating Behaviour or Food Quality and Design (WUR)
• Don't like bread products