| Food texture plays a key role in regulating human eating patterns. Dynamic sensory perception and individual preferences for specific tastes and textures have been reported to influence the speed and trajectory of food consumption, feelings of satiation and satiety, and overall food intake. The aim of this project was to 1. develop and characterize a model food system representing a spectrum of real food textures, 2. develop a method to track tongue movement in vivo during oral processing, 3. characterize and compare the oral processing patterns of a range of food textures, and 4. determine the impact of food texture upon satiation, satiety, and ad libitum food intake. An iso-caloric, whey protein-based model food system was developed to spanned a wide spectrum of food textures and characterized via rheological profiling and a trained sensory panel. A tongue tracking methodology was developed, calibrated, and validated by modifying a magnetic jaw tracking system to follow the movement of a magnetic proxy glued to a subject's tongue. Oral processing behaviors were characterized by recording muscle activity and jaw and tongue movements while 12 subjects consumed four whey protein model foods as well as three protein-fruit purees with or without oat particulates. A human clinical trial (n = 24) was also conducted to evaluate the impact of the texture of a pre-lunch snack upon subsequent reported satiation and satiety and ad libitum intake.;The model food system developed here consists of 11% protein, is iso-caloric and isovolumetric, and includes textures ranging from a fluid, thin and thick semisolids, and soft, intermediate, and firm solid gels. The tongue tracking method was developed by exchanging a traditional jaw-tracking magnet for a small circular magnet that was glued to the tongue; the method and MATLAB analysis software was calibrated in silico and ex vivo to account for inconsistencies imposed by tongue rotation. The tongue tracking equipment and developed software demonstrated accuracy within 0.2-4 mm for movements with limited tongue rotation within a practical oral processing space but requires additional modifications to reduce error to acceptable levels. Measurement accuracy decreased with increasing magnitudes of translational and rotational movements.;Oral processing patterns of protein-fruit purees found no significant differences between the control and puree with added fat. However, a puree with added oat particulates required significantly more time and muscle, jaw, and tongue effort, indicating that food particles may play a greater role in determining eating patterns than the continues phase. Subjects could be clearly segmented into fast and slow eaters but total tongue movements appeared to be independent of eating speed. Parameters of eating time, number of chews, muscle activity, and jaw and tongue movements significantly increased with increasing food viscosity or firmness. Whey protein model food textures were significantly differentiated by jaw movements but tongue movements only differentiated between fluid-like and solid-like foods. Wide variation was observed across subjects: slow eaters utilized larger tongue movement ranges and more jaw and tongue cycle repetitions than fast eaters across all food textures. These observations may indicate individual differences in acceptable food particle size at swallow or that slow eaters extend and modify their eating behaviors in search of a more desirable texture. No significant differences were observed in appetite ratings or lunch ad libitum intake following consumption of model food snacks of different textures; however, ad libitum intake in the following three hours increased with increasing snack viscosity or firmness. This research provides deeper insight into physiological eating patterns, the effects of oral processing on caloric consumption, and establishes a framework for the multi-disciplinary use of model food systems. |
