Nicolas Bordenave, PhD, Assistant Professor, Faculty of Health Sciences, School of Nutrition Sciences, University of Ottawa, Ottawa, Canada Mario G. Ferruzzi, PhD, Professor of Food Science and Nutrition, Department of Food, Bioprocessing and Nutrition Science, Plants for Human Health Institute, North Carolina State University, Raleigh, USA

• List of Contributors xvPreface xviiAcknowledgements xix1 Overview of Functional Foods 1Robin A. Ralston, Amy D. Mackey, Christopher T. Simons and Steven J. Schwartz1.1 Overview of Functional Foods 11.1.1 Foods and Nutrients are Linked to Health and Disease 11.1.2 Definition of Functional Foods 21.1.3 Functional Foods Market 21.1.4 How Functional Foods are Studied 31.2 Functional Foods and their Regulatory Aspects 61.3 Nanotechnologies in Functional Foods 71.4 Sensory Functionalities of Foods 9References 112 The In vivo Foundations for In vitro Testing of Functional Foods: The Gastrointestinal System 15Edwin K. McDonald, Heather Rasmussen, Christopher Forsyth and Ali Keshavarzian2.1 Introduction 152.2 Overview of the Structure of the Gastrointestinal Tract 162.2.1 Mucosa 172.2.2 Submucosa 172.2.3 Muscularis (or Muscularis Propria) and Serosa (or Adventitia) 182.2.4 Additional Components of the Gastrointestinal Tract: Accessory Organs, Vasculature, Innervation, Gut-Associated Lymphoid Tissue, and Microbiome 182.2.4.1 Accessory Organs of the GIT 182.2.4.2 Vasculature of the GIT: Blood and Lymphatic Supply 192.2.4.3 GIT Innervation 192.2.4.4 Gut-Associated Lymphoid Tissue 192.2.4.5 Intestinal Microbiome 202.3 Functions of the GIT and Associated In vitroModeling 202.3.1 Motility 212.3.1.1 The Foundations of GIT Motility: Smooth Muscle Cell Contractions (SMC) and ENS Regulation 222.3.1.2 In vitro Motility Modeling 232.3.2 Barrier Function, Secretion, and Absorption 242.3.2.1 Tight Junctions and the Barrier Function of the GIT 252.3.2.2 Intestinal Permeability: Definitions and the Role of Tight Junctions 262.3.2.3 Influences on Permeability 262.3.2.4 Absorption and Secretion 272.3.2.5 In vitro Models of Barrier Function, Absorption, and Secretion 282.3.3 Regulation of Immune Response 322.3.3.1 The Mucosal Immune Response Depends on IECs and GALT 322.3.3.2 Antigen Exclusion: The Importance of Secretory IgA 322.3.3.3 Antigen Sampling is Necessary for Immune Homeostasis 332.3.3.4 Antigen Presenting Cells and IECs Modulate T-cell Adaptive Immune Responses 342.3.3.5 In vitro Models of Mucosal Immunity 342.3.4 Storage, Fermentation, and Removal of Fecal Matter 352.3.4.1 Storage and Removal of Fecal Matter 352.3.4.2 Colonic Fermentation 362.3.4.3 Short-Chain Fatty Acids 372.3.4.4 In vitro Models of Fermentation 372.4 Limitations of In vitro Modeling of the Gastrointestinal Tract 382.5 Dynamic In vitro Models of Digestion 402.6 Conclusions 40References 413 In vivo Foundations of Sensory In vitro Testing Systems 53James Hollis3.1 Introduction 533.2 Taste 543.2.1 Overview 543.2.2 Taste Anatomy 553.2.3 Taste Coding 583.2.4 Transduction Mechanisms 583.2.4.1 Overview 583.2.4.2 Sour 593.2.4.3 Salt 603.2.4.4 Bitter 603.2.4.5 Sweet 613.2.4.6 Umami 623.2.4.7 Downstream Signaling of T1R and T2R 623.2.5 Non-Canonical Taste Modalities 633.2.5.1 Fat Taste 633.2.5.2 Calcium 643.3 Factors that Influence Taste Acuity 653.3.1 Saliva 653.3.2 Genetic Differences 663.4 Chemesthesis 663.5 The Olfactory System 673.5.1 Olfactory Anatomy 683.5.2 Olfactory Binding Proteins 683.5.3 Olfactory Receptors 693.5.4 Transduction Mechanisms 703.6 Texture 703.6.1 Mechanoreceptors 713.6.2 Proprioreceptors 713.6.3 Periodontal Receptors 723.6.4 Central Processing of Texture 723.7 Convergence of Taste, Smell and Texture to Produce Flavor 733.8 Concluding Remarks 73References 744 In vitro Models of Host–Microbial Interactions Within the Gastrointestinal Tract 87Ezgi Özcan, Rachel Levantovsky, and David A. Sela4.1 Introduction: The Human Gastrointestinal Tract 874.2 The Current State of In vitro Model Systems to Model Gut Ecosystems 914.3 Batch Culture Systems to Model the Gut Microbial Consortium 934.4 Continuous Systems to Model the Human GIT 964.5 Mucus-Immobilized Models of the Gut 1074.6 Models to Simulate Complex Host–Microbial Interactions 1114.7 Gastric–Small Intestine Model Systems 113References 1205 Macronutrient Nutritional Functionality of Carbohydrates, Proteins and Lipids: Digestibility, Absorption and Interactions 137Amanda Wright and Susan M. Tosh5.1 Introduction 1375.2 Applications and Considerations 1395.2.1 Carbohydrates 1395.2.2 Proteins 1415.2.3 Triglycerides 1425.3 Simulating Digestive Processes 1435.3.1 Oral Food Processing and Implications for Sample Preparation 1435.3.2 Gastric Phase 1455.3.3 Upper Intestinal Phase 1475.4 Interactions and Structural Considerations 1505.5 Post-Digestion Analysis 1515.6 In vitro Models 1545.6.1 Static Models 1545.6.1.1 INFOGEST Method for General Nutrient Digestion 1545.6.1.2 Englyst Method for Rate for Carbohydrate Digestion 1585.6.1.3 Streamlined Protein Digestibility 1595.6.1.4 pH Stat Method for Testing Emulsified Lipids 1605.6.2 Dynamic 1605.7 Limitation of In vitro Digestion Tests 1625.8 Conclusions 163References 1646 In vitro Approaches for Investigating the Bioaccessibility and Bioavailability of Dietary Nutrients and Bioactive Metabolites 171Chureeporn Chitchumroonchokchai and Mark L. Failla6.1 Introduction 1716.2 Static Models of In vitro Digestion 1736.3 Dynamic Models of In vitro Digestion 1766.4 Application of In vitro Digestion Method for Determining the Digestive Stability and Bioaccessibility of Dietary Compounds 1776.5 Caco-2 Cell Model 1806.6 Examples of the Effects of Bioaccessible Dietary Compounds on the Functions of Absorptive Intestinal Epithelial Cells 1836.7 Coupling the In vitro Digestion and Caco]2 Cell Models 1856.8 Co-culture Models Using Caco-2 Cells 1876.9 Conclusions 192References 1927 In vitro Models for Testing Toxicity in the Gastrointestinal Tract 201Ioannis Trantakis7.1 Introduction 2017.2 Advantages of In vitro Tests 2037.3 Limitations of Established Cell Line Models 2047.4 Single Cell Lines 2057.5 Co-culture Cell Models 2077.6 3D Co-culture Models 2097.7 Organs on a Chip 2107.8 Summary and Conclusions 214References 2148 In vitro Methods for Assessing Food Protein Allergenicity 219Ossanna Nashalian, Nicolas Bordenave and Chibuike Udenigwe8.1 Introduction 2198.2 Food Sensitization, Hypersensitivity and Allergy 2208.2.1 The Mechanism of Developing Food Hypersensitivities 2228.2.2 The Exposure to Allergens 2248.2.2.1 The Gastrointestinal (GI) Route 2258.2.2.2 The Respiratory Tract Route 2318.2.2.3 The Cutaneous Route 2318.3 Safety Needs and Regulatory Consideration in Detecting Allergens in Food 2318.4 In vitro Analytical Methods for Testing Known Allergens 2348.4.1 Protein-Based Approaches 2348.4.2 Immunoassay Approaches 2388.4.2.1 Enzyme-Linked Immunosorbent Assay (ELISA) 2388.4.2.2 Other Immunoassay-based Methods 2408.4.3 DNA-based Approaches 2428.4.3.1 Real-Time PCR 2428.4.3.2 Microarray Assay 2428.4.4 Mass Spectrometry-based Approaches 2438.4.5 In vitro Cell-based Methods for the Prediction of Food Allergenicity 2438.4.6 In Silico Methods for the Prediction of Food Allergenicity 246References 2519 Challenges of Linking In vitro Analysis to Flavor Perception 263Avinash Kant and Rob Linforth9.1 Introduction 2639.2 What is “Flavor”? 2649.2.1 Flavor Analysis Overview 2649.2.2 Significance of Aroma Compounds 2659.2.3 Challenges of Food Flavor Compounds 2669.3 Overview of Flavor Analysis Techniques 2699.3.1 Key Isolation Techniques 2699.3.2 Taste Compound Isolation 2709.3.3 Aroma Compound Isolation 2709.3.3.1 Solvent Extraction 2709.3.3.2 Distillation 2719.3.3.3 Headspace 2719.3.4 Taste Compound Detection 2729.3.5 Aroma Compound Separation and Detection 2729.4 Further Developments in Aroma Analysis 2739.4.1 Gas Chromatography–Olfactometry 2739.4.2 Interpretation of GC–Olfactometry Data 2749.4.3 Recent Advances in Aroma Extract Preparation 2779.4.4 Solid-Phase MicroExtraction 2779.4.5 Advances in Solvent Assisted Flavor Extraction 2799.4.6 Challenges of Single Aroma Compound Data Interpretation 2809.4.7 Correlation of the Sensory Experience with GC Data 2819.5 Recent Advances Developing In vitro Flavor Analysis Tools 2829.5.1 Electronic Devices for Flavor Assessment 2829.5.2 eNose 2839.5.3 eTongue 2849.5.4 Further Developments in Electronic Flavor Devices 2859.6 Model Mouth Systems 2869.7 Real Time Studies of Flavor Delivery 2879.8 Future Direction of In vitro Flavor Studies 2929.8.1 Taste Research 2929.8.2 Taste Cell Model Systems 2949.8.3 Odor Receptors 2959.8.4 Sensomics Approach 2969.8.5 Interaction Effects and Multi-modal Perception 2979.8.6 Brain Imaging by fMRI 2979.9 Summary 298References 300Index 305

Nicolas Bordenave, PhD, Assistant Professor, Faculty of Health Sciences, School of Nutrition Sciences, University of Ottawa, Ottawa, Canada Mario G. Ferruzzi, PhD, Professor of Food Science and Nutrition, Department of Food, Bioprocessing and Nutrition Science, Plants for Human Health Institute, North Carolina State University, Raleigh, USA

• List of Contributors xvPreface xviiAcknowledgements xix1 Overview of Functional Foods 1Robin A. Ralston, Amy D. Mackey, Christopher T. Simons and Steven J. Schwartz1.1 Overview of Functional Foods 11.1.1 Foods and Nutrients are Linked to Health and Disease 11.1.2 Definition of Functional Foods 21.1.3 Functional Foods Market 21.1.4 How Functional Foods are Studied 31.2 Functional Foods and their Regulatory Aspects 61.3 Nanotechnologies in Functional Foods 71.4 Sensory Functionalities of Foods 9References 112 The In vivo Foundations for In vitro Testing of Functional Foods: The Gastrointestinal System 15Edwin K. McDonald, Heather Rasmussen, Christopher Forsyth and Ali Keshavarzian2.1 Introduction 152.2 Overview of the Structure of the Gastrointestinal Tract 162.2.1 Mucosa 172.2.2 Submucosa 172.2.3 Muscularis (or Muscularis Propria) and Serosa (or Adventitia) 182.2.4 Additional Components of the Gastrointestinal Tract: Accessory Organs, Vasculature, Innervation, Gut-Associated Lymphoid Tissue, and Microbiome 182.2.4.1 Accessory Organs of the GIT 182.2.4.2 Vasculature of the GIT: Blood and Lymphatic Supply 192.2.4.3 GIT Innervation 192.2.4.4 Gut-Associated Lymphoid Tissue 192.2.4.5 Intestinal Microbiome 202.3 Functions of the GIT and Associated In vitroModeling 202.3.1 Motility 212.3.1.1 The Foundations of GIT Motility: Smooth Muscle Cell Contractions (SMC) and ENS Regulation 222.3.1.2 In vitro Motility Modeling 232.3.2 Barrier Function, Secretion, and Absorption 242.3.2.1 Tight Junctions and the Barrier Function of the GIT 252.3.2.2 Intestinal Permeability: Definitions and the Role of Tight Junctions 262.3.2.3 Influences on Permeability 262.3.2.4 Absorption and Secretion 272.3.2.5 In vitro Models of Barrier Function, Absorption, and Secretion 282.3.3 Regulation of Immune Response 322.3.3.1 The Mucosal Immune Response Depends on IECs and GALT 322.3.3.2 Antigen Exclusion: The Importance of Secretory IgA 322.3.3.3 Antigen Sampling is Necessary for Immune Homeostasis 332.3.3.4 Antigen Presenting Cells and IECs Modulate T-cell Adaptive Immune Responses 342.3.3.5 In vitro Models of Mucosal Immunity 342.3.4 Storage, Fermentation, and Removal of Fecal Matter 352.3.4.1 Storage and Removal of Fecal Matter 352.3.4.2 Colonic Fermentation 362.3.4.3 Short-Chain Fatty Acids 372.3.4.4 In vitro Models of Fermentation 372.4 Limitations of In vitro Modeling of the Gastrointestinal Tract 382.5 Dynamic In vitro Models of Digestion 402.6 Conclusions 40References 413 In vivo Foundations of Sensory In vitro Testing Systems 53James Hollis3.1 Introduction 533.2 Taste 543.2.1 Overview 543.2.2 Taste Anatomy 553.2.3 Taste Coding 583.2.4 Transduction Mechanisms 583.2.4.1 Overview 583.2.4.2 Sour 593.2.4.3 Salt 603.2.4.4 Bitter 603.2.4.5 Sweet 613.2.4.6 Umami 623.2.4.7 Downstream Signaling of T1R and T2R 623.2.5 Non-Canonical Taste Modalities 633.2.5.1 Fat Taste 633.2.5.2 Calcium 643.3 Factors that Influence Taste Acuity 653.3.1 Saliva 653.3.2 Genetic Differences 663.4 Chemesthesis 663.5 The Olfactory System 673.5.1 Olfactory Anatomy 683.5.2 Olfactory Binding Proteins 683.5.3 Olfactory Receptors 693.5.4 Transduction Mechanisms 703.6 Texture 703.6.1 Mechanoreceptors 713.6.2 Proprioreceptors 713.6.3 Periodontal Receptors 723.6.4 Central Processing of Texture 723.7 Convergence of Taste, Smell and Texture to Produce Flavor 733.8 Concluding Remarks 73References 744 In vitro Models of Host–Microbial Interactions Within the Gastrointestinal Tract 87Ezgi Özcan, Rachel Levantovsky, and David A. Sela4.1 Introduction: The Human Gastrointestinal Tract 874.2 The Current State of In vitro Model Systems to Model Gut Ecosystems 914.3 Batch Culture Systems to Model the Gut Microbial Consortium 934.4 Continuous Systems to Model the Human GIT 964.5 Mucus-Immobilized Models of the Gut 1074.6 Models to Simulate Complex Host–Microbial Interactions 1114.7 Gastric–Small Intestine Model Systems 113References 1205 Macronutrient Nutritional Functionality of Carbohydrates, Proteins and Lipids: Digestibility, Absorption and Interactions 137Amanda Wright and Susan M. Tosh5.1 Introduction 1375.2 Applications and Considerations 1395.2.1 Carbohydrates 1395.2.2 Proteins 1415.2.3 Triglycerides 1425.3 Simulating Digestive Processes 1435.3.1 Oral Food Processing and Implications for Sample Preparation 1435.3.2 Gastric Phase 1455.3.3 Upper Intestinal Phase 1475.4 Interactions and Structural Considerations 1505.5 Post-Digestion Analysis 1515.6 In vitro Models 1545.6.1 Static Models 1545.6.1.1 INFOGEST Method for General Nutrient Digestion 1545.6.1.2 Englyst Method for Rate for Carbohydrate Digestion 1585.6.1.3 Streamlined Protein Digestibility 1595.6.1.4 pH Stat Method for Testing Emulsified Lipids 1605.6.2 Dynamic 1605.7 Limitation of In vitro Digestion Tests 1625.8 Conclusions 163References 1646 In vitro Approaches for Investigating the Bioaccessibility and Bioavailability of Dietary Nutrients and Bioactive Metabolites 171Chureeporn Chitchumroonchokchai and Mark L. Failla6.1 Introduction 1716.2 Static Models of In vitro Digestion 1736.3 Dynamic Models of In vitro Digestion 1766.4 Application of In vitro Digestion Method for Determining the Digestive Stability and Bioaccessibility of Dietary Compounds 1776.5 Caco-2 Cell Model 1806.6 Examples of the Effects of Bioaccessible Dietary Compounds on the Functions of Absorptive Intestinal Epithelial Cells 1836.7 Coupling the In vitro Digestion and Caco]2 Cell Models 1856.8 Co-culture Models Using Caco-2 Cells 1876.9 Conclusions 192References 1927 In vitro Models for Testing Toxicity in the Gastrointestinal Tract 201Ioannis Trantakis7.1 Introduction 2017.2 Advantages of In vitro Tests 2037.3 Limitations of Established Cell Line Models 2047.4 Single Cell Lines 2057.5 Co-culture Cell Models 2077.6 3D Co-culture Models 2097.7 Organs on a Chip 2107.8 Summary and Conclusions 214References 2148 In vitro Methods for Assessing Food Protein Allergenicity 219Ossanna Nashalian, Nicolas Bordenave and Chibuike Udenigwe8.1 Introduction 2198.2 Food Sensitization, Hypersensitivity and Allergy 2208.2.1 The Mechanism of Developing Food Hypersensitivities 2228.2.2 The Exposure to Allergens 2248.2.2.1 The Gastrointestinal (GI) Route 2258.2.2.2 The Respiratory Tract Route 2318.2.2.3 The Cutaneous Route 2318.3 Safety Needs and Regulatory Consideration in Detecting Allergens in Food 2318.4 In vitro Analytical Methods for Testing Known Allergens 2348.4.1 Protein-Based Approaches 2348.4.2 Immunoassay Approaches 2388.4.2.1 Enzyme-Linked Immunosorbent Assay (ELISA) 2388.4.2.2 Other Immunoassay-based Methods 2408.4.3 DNA-based Approaches 2428.4.3.1 Real-Time PCR 2428.4.3.2 Microarray Assay 2428.4.4 Mass Spectrometry-based Approaches 2438.4.5 In vitro Cell-based Methods for the Prediction of Food Allergenicity 2438.4.6 In Silico Methods for the Prediction of Food Allergenicity 246References 2519 Challenges of Linking In vitro Analysis to Flavor Perception 263Avinash Kant and Rob Linforth9.1 Introduction 2639.2 What is “Flavor”? 2649.2.1 Flavor Analysis Overview 2649.2.2 Significance of Aroma Compounds 2659.2.3 Challenges of Food Flavor Compounds 2669.3 Overview of Flavor Analysis Techniques 2699.3.1 Key Isolation Techniques 2699.3.2 Taste Compound Isolation 2709.3.3 Aroma Compound Isolation 2709.3.3.1 Solvent Extraction 2709.3.3.2 Distillation 2719.3.3.3 Headspace 2719.3.4 Taste Compound Detection 2729.3.5 Aroma Compound Separation and Detection 2729.4 Further Developments in Aroma Analysis 2739.4.1 Gas Chromatography–Olfactometry 2739.4.2 Interpretation of GC–Olfactometry Data 2749.4.3 Recent Advances in Aroma Extract Preparation 2779.4.4 Solid-Phase MicroExtraction 2779.4.5 Advances in Solvent Assisted Flavor Extraction 2799.4.6 Challenges of Single Aroma Compound Data Interpretation 2809.4.7 Correlation of the Sensory Experience with GC Data 2819.5 Recent Advances Developing In vitro Flavor Analysis Tools 2829.5.1 Electronic Devices for Flavor Assessment 2829.5.2 eNose 2839.5.3 eTongue 2849.5.4 Further Developments in Electronic Flavor Devices 2859.6 Model Mouth Systems 2869.7 Real Time Studies of Flavor Delivery 2879.8 Future Direction of In vitro Flavor Studies 2929.8.1 Taste Research 2929.8.2 Taste Cell Model Systems 2949.8.3 Odor Receptors 2959.8.4 Sensomics Approach 2969.8.5 Interaction Effects and Multi-modal Perception 2979.8.6 Brain Imaging by fMRI 2979.9 Summary 298References 300Index 305

Nicolas Bordenave, PhD, Assistant Professor, Faculty of Health Sciences, School of Nutrition Sciences, University of Ottawa, Ottawa, Canada Mario G. Ferruzzi, PhD, Professor of Food Science and Nutrition, Department of Food, Bioprocessing and Nutrition Science, Plants for Human Health Institute, North Carolina State University, Raleigh, USA

• List of Contributors xvPreface xviiAcknowledgements xix1 Overview of Functional Foods 1Robin A. Ralston, Amy D. Mackey, Christopher T. Simons and Steven J. Schwartz1.1 Overview of Functional Foods 11.1.1 Foods and Nutrients are Linked to Health and Disease 11.1.2 Definition of Functional Foods 21.1.3 Functional Foods Market 21.1.4 How Functional Foods are Studied 31.2 Functional Foods and their Regulatory Aspects 61.3 Nanotechnologies in Functional Foods 71.4 Sensory Functionalities of Foods 9References 112 The In vivo Foundations for In vitro Testing of Functional Foods: The Gastrointestinal System 15Edwin K. McDonald, Heather Rasmussen, Christopher Forsyth and Ali Keshavarzian2.1 Introduction 152.2 Overview of the Structure of the Gastrointestinal Tract 162.2.1 Mucosa 172.2.2 Submucosa 172.2.3 Muscularis (or Muscularis Propria) and Serosa (or Adventitia) 182.2.4 Additional Components of the Gastrointestinal Tract: Accessory Organs, Vasculature, Innervation, Gut-Associated Lymphoid Tissue, and Microbiome 182.2.4.1 Accessory Organs of the GIT 182.2.4.2 Vasculature of the GIT: Blood and Lymphatic Supply 192.2.4.3 GIT Innervation 192.2.4.4 Gut-Associated Lymphoid Tissue 192.2.4.5 Intestinal Microbiome 202.3 Functions of the GIT and Associated In vitroModeling 202.3.1 Motility 212.3.1.1 The Foundations of GIT Motility: Smooth Muscle Cell Contractions (SMC) and ENS Regulation 222.3.1.2 In vitro Motility Modeling 232.3.2 Barrier Function, Secretion, and Absorption 242.3.2.1 Tight Junctions and the Barrier Function of the GIT 252.3.2.2 Intestinal Permeability: Definitions and the Role of Tight Junctions 262.3.2.3 Influences on Permeability 262.3.2.4 Absorption and Secretion 272.3.2.5 In vitro Models of Barrier Function, Absorption, and Secretion 282.3.3 Regulation of Immune Response 322.3.3.1 The Mucosal Immune Response Depends on IECs and GALT 322.3.3.2 Antigen Exclusion: The Importance of Secretory IgA 322.3.3.3 Antigen Sampling is Necessary for Immune Homeostasis 332.3.3.4 Antigen Presenting Cells and IECs Modulate T-cell Adaptive Immune Responses 342.3.3.5 In vitro Models of Mucosal Immunity 342.3.4 Storage, Fermentation, and Removal of Fecal Matter 352.3.4.1 Storage and Removal of Fecal Matter 352.3.4.2 Colonic Fermentation 362.3.4.3 Short-Chain Fatty Acids 372.3.4.4 In vitro Models of Fermentation 372.4 Limitations of In vitro Modeling of the Gastrointestinal Tract 382.5 Dynamic In vitro Models of Digestion 402.6 Conclusions 40References 413 In vivo Foundations of Sensory In vitro Testing Systems 53James Hollis3.1 Introduction 533.2 Taste 543.2.1 Overview 543.2.2 Taste Anatomy 553.2.3 Taste Coding 583.2.4 Transduction Mechanisms 583.2.4.1 Overview 583.2.4.2 Sour 593.2.4.3 Salt 603.2.4.4 Bitter 603.2.4.5 Sweet 613.2.4.6 Umami 623.2.4.7 Downstream Signaling of T1R and T2R 623.2.5 Non-Canonical Taste Modalities 633.2.5.1 Fat Taste 633.2.5.2 Calcium 643.3 Factors that Influence Taste Acuity 653.3.1 Saliva 653.3.2 Genetic Differences 663.4 Chemesthesis 663.5 The Olfactory System 673.5.1 Olfactory Anatomy 683.5.2 Olfactory Binding Proteins 683.5.3 Olfactory Receptors 693.5.4 Transduction Mechanisms 703.6 Texture 703.6.1 Mechanoreceptors 713.6.2 Proprioreceptors 713.6.3 Periodontal Receptors 723.6.4 Central Processing of Texture 723.7 Convergence of Taste, Smell and Texture to Produce Flavor 733.8 Concluding Remarks 73References 744 In vitro Models of Host–Microbial Interactions Within the Gastrointestinal Tract 87Ezgi Özcan, Rachel Levantovsky, and David A. Sela4.1 Introduction: The Human Gastrointestinal Tract 874.2 The Current State of In vitro Model Systems to Model Gut Ecosystems 914.3 Batch Culture Systems to Model the Gut Microbial Consortium 934.4 Continuous Systems to Model the Human GIT 964.5 Mucus-Immobilized Models of the Gut 1074.6 Models to Simulate Complex Host–Microbial Interactions 1114.7 Gastric–Small Intestine Model Systems 113References 1205 Macronutrient Nutritional Functionality of Carbohydrates, Proteins and Lipids: Digestibility, Absorption and Interactions 137Amanda Wright and Susan M. Tosh5.1 Introduction 1375.2 Applications and Considerations 1395.2.1 Carbohydrates 1395.2.2 Proteins 1415.2.3 Triglycerides 1425.3 Simulating Digestive Processes 1435.3.1 Oral Food Processing and Implications for Sample Preparation 1435.3.2 Gastric Phase 1455.3.3 Upper Intestinal Phase 1475.4 Interactions and Structural Considerations 1505.5 Post-Digestion Analysis 1515.6 In vitro Models 1545.6.1 Static Models 1545.6.1.1 INFOGEST Method for General Nutrient Digestion 1545.6.1.2 Englyst Method for Rate for Carbohydrate Digestion 1585.6.1.3 Streamlined Protein Digestibility 1595.6.1.4 pH Stat Method for Testing Emulsified Lipids 1605.6.2 Dynamic 1605.7 Limitation of In vitro Digestion Tests 1625.8 Conclusions 163References 1646 In vitro Approaches for Investigating the Bioaccessibility and Bioavailability of Dietary Nutrients and Bioactive Metabolites 171Chureeporn Chitchumroonchokchai and Mark L. Failla6.1 Introduction 1716.2 Static Models of In vitro Digestion 1736.3 Dynamic Models of In vitro Digestion 1766.4 Application of In vitro Digestion Method for Determining the Digestive Stability and Bioaccessibility of Dietary Compounds 1776.5 Caco-2 Cell Model 1806.6 Examples of the Effects of Bioaccessible Dietary Compounds on the Functions of Absorptive Intestinal Epithelial Cells 1836.7 Coupling the In vitro Digestion and Caco]2 Cell Models 1856.8 Co-culture Models Using Caco-2 Cells 1876.9 Conclusions 192References 1927 In vitro Models for Testing Toxicity in the Gastrointestinal Tract 201Ioannis Trantakis7.1 Introduction 2017.2 Advantages of In vitro Tests 2037.3 Limitations of Established Cell Line Models 2047.4 Single Cell Lines 2057.5 Co-culture Cell Models 2077.6 3D Co-culture Models 2097.7 Organs on a Chip 2107.8 Summary and Conclusions 214References 2148 In vitro Methods for Assessing Food Protein Allergenicity 219Ossanna Nashalian, Nicolas Bordenave and Chibuike Udenigwe8.1 Introduction 2198.2 Food Sensitization, Hypersensitivity and Allergy 2208.2.1 The Mechanism of Developing Food Hypersensitivities 2228.2.2 The Exposure to Allergens 2248.2.2.1 The Gastrointestinal (GI) Route 2258.2.2.2 The Respiratory Tract Route 2318.2.2.3 The Cutaneous Route 2318.3 Safety Needs and Regulatory Consideration in Detecting Allergens in Food 2318.4 In vitro Analytical Methods for Testing Known Allergens 2348.4.1 Protein-Based Approaches 2348.4.2 Immunoassay Approaches 2388.4.2.1 Enzyme-Linked Immunosorbent Assay (ELISA) 2388.4.2.2 Other Immunoassay-based Methods 2408.4.3 DNA-based Approaches 2428.4.3.1 Real-Time PCR 2428.4.3.2 Microarray Assay 2428.4.4 Mass Spectrometry-based Approaches 2438.4.5 In vitro Cell-based Methods for the Prediction of Food Allergenicity 2438.4.6 In Silico Methods for the Prediction of Food Allergenicity 246References 2519 Challenges of Linking In vitro Analysis to Flavor Perception 263Avinash Kant and Rob Linforth9.1 Introduction 2639.2 What is “Flavor”? 2649.2.1 Flavor Analysis Overview 2649.2.2 Significance of Aroma Compounds 2659.2.3 Challenges of Food Flavor Compounds 2669.3 Overview of Flavor Analysis Techniques 2699.3.1 Key Isolation Techniques 2699.3.2 Taste Compound Isolation 2709.3.3 Aroma Compound Isolation 2709.3.3.1 Solvent Extraction 2709.3.3.2 Distillation 2719.3.3.3 Headspace 2719.3.4 Taste Compound Detection 2729.3.5 Aroma Compound Separation and Detection 2729.4 Further Developments in Aroma Analysis 2739.4.1 Gas Chromatography–Olfactometry 2739.4.2 Interpretation of GC–Olfactometry Data 2749.4.3 Recent Advances in Aroma Extract Preparation 2779.4.4 Solid-Phase MicroExtraction 2779.4.5 Advances in Solvent Assisted Flavor Extraction 2799.4.6 Challenges of Single Aroma Compound Data Interpretation 2809.4.7 Correlation of the Sensory Experience with GC Data 2819.5 Recent Advances Developing In vitro Flavor Analysis Tools 2829.5.1 Electronic Devices for Flavor Assessment 2829.5.2 eNose 2839.5.3 eTongue 2849.5.4 Further Developments in Electronic Flavor Devices 2859.6 Model Mouth Systems 2869.7 Real Time Studies of Flavor Delivery 2879.8 Future Direction of In vitro Flavor Studies 2929.8.1 Taste Research 2929.8.2 Taste Cell Model Systems 2949.8.3 Odor Receptors 2959.8.4 Sensomics Approach 2969.8.5 Interaction Effects and Multi-modal Perception 2979.8.6 Brain Imaging by fMRI 2979.9 Summary 298References 300Index 305