Computer modeling of digestive processes in the alimentary tract and their physiological regulation mechanisms: closing the gap between digestion models and behavior.

Introduction: A model has been developed for in silico simulation of digestion and its physiological feedback mechanisms.

Methods: The model is based on known physiology described in the literature and is able to describe the complexity of many simultaneous processes related to food digestion.

Results: Despite the early stage of development of the model, it already encompasses a large number of processes that occur simultaneously, enabling the prediction of a large number of post-prandial physiological markers, which can be highly functional in combination with in vitro, organ-on-a-chip and digital twin models purposed to measure the physiological properties of organs and to predict the effect of adjusted food composition in normal and diseased states.

Effects of inhomogeneity on triglyceride digestion of emulsions using an in vitro digestion model (Tiny TIM).

The colloidal behaviour and extent of lipolysis of various emulsions stabilized by whey protein and Tween were studied using the TNO Intestinal Model (TIM) extended with a purposely designed gastric compartment. The in vitro results suggest that creaming of a fatty layer in the gastric region causes a delay in fat entering the small intestinal region, delays and reduces the free fatty acid content in the small intestinal lumen and delays fat absorption. It was shown that controlling the pH with pig gastric juice instead of simulated gastric juice delayed creaming of the emulsions significantly, which resulted in faster gastric lipolysis.

Formation of β Polymorphs in Milk Fats with Large Differences in Triacylglycerol Profiles.

In this study, we characterized the polymorphism of milk fat (MF) with various TAG compositions during isothermal crystallization at 20 °C. TAG composition of MF from seven individual cows was determined using GC-FID and MALDI-TOF MS, and MF polymorphism was studied using X-ray diffraction. Results showed that TAG profile determines the polymorphic behavior of MF.

Development of the Digestive System-Experimental Challenges and Approaches of Infant Lipid Digestion.

At least during the first 6 months after birth, the nutrition of infants should ideally consist of human milk which provides 40-60 % of energy from lipids. Beyond energy, human milk also delivers lipids with a specific functionality, such as essential fatty acids (FA), phospholipids, and cholesterol. Healthy development, especially of the nervous and digestive systems, depends fundamentally on these.

Colloidal aspects of texture perception.

Recently, considerable attention has been given to the understanding of texture attributes that cannot directly be related to physical properties of food, such as creamy, crumbly and watery. The perception of these attributes is strongly related to the way the food is processed during food intake, mastication, swallowing of it and during the cleaning of the mouth after swallowing. Moreover, their perception is modulated by the interaction with other basic attributes, such as taste and aroma attributes (e.

Direct observation of adhesion and spreading of emulsion droplets at solid surfaces.

Sensory perception of fat is related to orally perceived in-mouth friction. From this perspective, we investigate adhesion and spreading of emulsion droplets on solid surfaces and connect it to the ability of food emulsions to lower friction. Furthermore, we study what the contribution is of the separate colloidal forces on droplet adhesion.

Fat retention at the tongue and the role of saliva: adhesion and spreading of 'protein-poor' versus 'protein-rich' emulsions.

Fat perception of food emulsions has been found to relate to in-mouth friction. Previously, we have shown that friction under mouth-like conditions strongly depends on the sensitivity of protein-stabilized emulsion droplets to coalescence. Here, we investigated whether this also implies that oral fat retention depends in a similar manner on the stability of the emulsion droplets against coalescence.

Complex formation in mixtures of lysozyme-stabilized emulsions and human saliva.

In this paper, we studied the interaction between human unstimulated saliva and lysozyme-stabilized oil-in-water emulsions (10 wt/wt% oil phase, 10 mM NaCl, pH 6.7), to reveal the driving force for flocculation of these emulsions. Confocal scanning laser microscopy (CSLM) showed formation of complexes between salivary proteins and lysozyme adsorbed at the oil-water interface and lysozyme in solution as well.

Scaling behavior of delayed demixing, rheology, and microstructure of emulsions flocculated by depletion and bridging.

This paper describes an experimental comparison of microstructure, rheology, and demixing of bridging- and depletion-flocculated oil-in-water emulsions. Confocal scanning laser microscopy imaging showed that bridging-flocculated emulsions were heterogeneous over larger length scales than depletion-flocculated emulsions. As a consequence, G' as determined from diffusing wave spectroscopy (DWS) corresponded well with G' as measured macroscopically for the depletion-flocculated emulsions, but this correspondence was not found for the bridging-flocculated emulsions.