About this book
This book is aimed at physiologists, pharmacologists, nutritionists and food technologists whose work requires an understanding of the physical processes of digestion.
The book provides an overview of what is known of the physical processes of digestion in man and other simple-stomached vertebrates in two broad sections. The first section considers the physical constraints that govern the dissolution and digestion of the various macronutrients within food particles, and the physical factors that influence their subsequent transfer to the gut wall, notably the rheology and permeability of digesta. The second section examines the effects of the alimentary, mechanical and biophysical processes on mixing and mass transfer. Included is a comprehensive review of the effects of the various types of contractile activity in the gut wall in securing efficient mixing and onflow of digesta through the various segments of the gut. The section also examines what is known of the actions of the mucinous and cellular components of the gut wall in lubricating the passage of digesta and in limiting the permeation and absorption of nutrients, pharmaceuticals and microbial products. The section concludes with a review of the effects of the various physical and morphological components of the gut wall that constitute the ‘unstirred water layer’ on the process of absorption.
The authors are leaders in their field and have extensively researched the literature. The work cites over 1500 references including those pertaining to the latest developments.
Content Level » Research
Related subjects » Chemistry - Food Science & Nutrition
- Introduction Flow mixing and absorption.
- The physical problems of extracting nutrients from food items and the possible macroscopic and microscopic solutions.
- The digestive tube and its limitations.
- Solid to liquid to solid
- Methods for evaluating the physical properties of digesta
- Particle size
- Rheology Viscometry
- Viscoelastic behaviour
- Time dependent behaviour
- Permeametry Hindered settling function
- Permeability and other measures
- Methods for evaluating the relationship between motility and flow of digesta
- Solid and liquid phase markers
- Reactor mixing
- Spatiotemporal mapping
- Physical behaviour of fluid digesta
- Macroscopic effects
- Newtonian and non Newtonian behaviour of fluids.
- Where digesta fit in this system the kinetics of digesta flow
- Securing efficient absorption from fluids and non-Newtonian fluids, chemical reactor theory and problems
- Backflow form coiled elements
- Physical behaviour of solid digesta
- The continuum between solids and liquids viscoselasticity securing efficient absorption from fluids and from viscoelastic fluids
- Permeability extrusion of the liquid phase
- Propulsion and mixing of digesta the interplay between the gut wall and its contents
- Tension and stretch receptors in the enteric nervous system
- Maintaining the flow of digesta problems of narrowing and expanding
- Co-evolution of motility and the physical properties of digesta
- Mucus and the unstirred water layer.
- Flow in the paravillus space and the crypts.
- Tight junctions permeability and fluid flow
- Glycocalyceal signalling of shear The physics of food
- What is known about how the physical structure of food interacts with the digestive processes e.g starch granule digestion digestion of proteinaceous aggregates etc ( Dr Allan Hardacre NZ Crop and Food )
- Flow and microorganisms
- Adaptions of micro-organisms to move within digesta and mucus
- Glycocalyceal signalling
- Messing with the properties of digesta
- Adulterating foods with viscoactive substances
- Nutraceuticals planning the rate of nutrient release.
- Modulating lumen pressure
- Microencapsulation and adherence to the gut wall.
Authors & Editors
Roger Lentle, graduated in medicine and in biochemistry from University College London and gained his PhD at Massey University, New Zealand. He has published extensively on the physical processes of digestion and is Professor of Digestive Biomechanics at the Institute of Food Nutrition and Human Health at Massey University.
Patrick Janssen, gained his PhD in chemical and process engineering at Canterbury University, New Zealand. He worked in the fields of process control and milk fat processing in the dairy industry before developing an interest in the physical processes of digestion. Currently he is a senior lecturer at the Institute of Food Nutrition and Human Health at Massey University.