Glass Transition and Phase Transitions in Food and Biological Materials

About the Editor: Jasim Ahmed is Research Scientist, Kuwait Institute for Scientific Research, Kuwait. Associate Editors: Mohammad Shafiur Rahman is Professor, Sultan Qaboos University, Sultanate of Oman. Yrjö H. Roos is Professor, School of Food and Nutritional Sciences, University College Cork, Ireland.

List of Contributors xiii

Preface xvii

1 Thermal and Relaxation Properties of Food and Biopolymers with Emphasis onWater 1
Jan Swenson and Helén Jansson

1.1 Introduction 1

1.2 Glass Transition and Relaxation Dynamics of Sugar Solutions and Sugar-Rich Food 3

1.3 Glass Transition and Relaxation Dynamics of Proteins 8

1.4 Confined Aqueous Solutions and the Failure of Gordon-Taylor Extrapolations to High-Water Contents 18

1.5 Concluding Discussion 22

References 24

2 Glass Transition Thermodynamics and Kinetics 31
K. Muthukumarappan and G.J. Swamy

2.1 Introduction 31

2.2 Theories of Glass Transition 32

2.3 Reaction Kinetics – Basic Principle 35

2.4 Reaction Kinetics – Temperature Dependence 37

2.5 Glass Transition in Sugars 39

2.6 Glass Transition in Dairy Ingredients 41

2.7 Glass Transition in Fruit Powders 42

2.8 Conclusion and Direction for Future Studies 43

References 44

3 Glass Transition of Globular Proteins from Thermal and High Pressure Perspectives 49
Sobhan Savadkoohi, Anna Bannikova and Stefan Kasapis

3.1 Factors Affecting Protein Functionality 49

3.2 High-Pressure Processing 55

3.3 Specific Examples of Pressure Effects 64

3.4 The Time-temperature-pressure Effect on the Vitrification of High Solid Systems 70

3.5 High Pressure Effects on the Structural Properties of Condensed Globular Proteins 79

3.6 Concluding Remarks 98

References 102

4 Crystal-Melt Phase Change of Food and Biopolymers 119
Sudipta Senapati, Dipak Rana and Pralay Maiti

4.1 Introduction 119

4.2 Thermodynamics of Crystallization and Melting 120

4.3 Role ofWater in the Phase Transition of Food 124

4.4 Classification of Phase Transitions 124

4.5 Crystallization,Melting and Morphology 126

4.6 Crystal Growth 130

4.7 Crystallization Kinetics 131

4.8 Crystal Melting and Morphology 131

4.9 Conclusions 133

Acknowledgements 135

References 135

5 Thermal Properties of Food and Biopolymer Using Relaxation Techniques 141
Arun KumarMahanta, Dipak Rana, Akhil Kumar Sen and PralayMaiti

5.1 Introduction 141

5.2 RelaxationThrough Nuclear Magnetic Resonance (NMR) 142

5.3 RelaxationThrough Dielectric Spectroscopy 146

5.4 RelaxationThrough Differential Scanning Calorimetry (DSC) 149

5.5 RelaxationThrough Dynamic Mechanical Measurements 151

5.6 Conclusions 154

Acknowledgement 154

References 154

6 Plasticizers for Biopolymer Films 159
Yasir Ali Arfat

6.1 Introduction 159

6.2 Plasticizer Classification 160

6.3 Mechanisms of Plasticization 161

6.4 Plasticizers for Protein-Based Films 161

6.5 Polysaccharide-Based Films 166

6.6 Plasticizers for Poly(lactic acid) Films 171

6.7 Conclusion 175

References 176

7 Crystallization Kinetics and Applications to Food and Biopolymers 183
Jasim Ahmed and Santanu Basu

7.1 Introduction 183

7.2 Crystal Growth and Nucleation 183

7.3 Shape of Crystals 184

7.4 Polymorphism 185

7.5 Crystallization Kinetics 185

7.6 Isothermal Crystallization 186

7.7 Non-Isothermal Crystallization Kinetics 190

7.8 Ozawa Model 193

7.9 Crystallization in Foods 194

7.10 Selected Case Studies 194

7.11 Conclusion 202

References 203

8 Thermal Transitions ,Mechanical Relaxations and Microstructure of Hydrated Gluten Networks 207
Vassilis Kontogiorgos

8.1 Introduction 207

8.2 Thermal Transitions of Hydrated Gluten Networks 208

8.3 Mechanical Relaxations of Hydrated Gluten Network 210

8.4 Calculation of Relaxation Spectra of Hydrated Gluten Networks 214

8.5 Microstructure of Gluten Network 217

8.6 Concluding Remarks 219

References 219

9 Implication of Glass Transition to Drying and Stability of Dried Foods 225
Yrjö H. Roos

9.1 Introduction 225

9.2 The Glass Transition 226

9.3 Structural Relaxations 229

9.4 Drying and Dehydrated Solids 232

9.5 Conclusion 235

References 236

10 Water-Glass Transition Temperature Profile During Spray Drying of Sugar-Rich Foods 239
Imran Ahmad and Loc Thai Nguyen

10.1 Introduction 239

10.2 Spray Dryer 239

10.3 Glass Transition 240

10.4 Issues Related with Sugar-Rich Foods 240

10.5 Stickiness, Deposition and Caking 241

10.6 Modeling and Prediction of Tg Profile 242

10.7 Strategies to Reduce Stickiness in Sugar-Rich Foods 243

10.8 Conclusions 246

References 247

11 State Diagram of Foods and Its Importance to Food Stability During Storage and Processing 251
Mohammad Shafiur Rahman

11.1 Introduction 251

11.2 State Diagram and Their Boundaries 251

11.3 BET-Momolayer Line 255

11.4 Water Boiling and Solids-Melting Lines 255

11.5 Macro-Micro Region in the State Diagram 256

11.6 Applications of State Diagram in Determining Food Stability 256

Acknowledgement 258

References 258

12 Thermal Properties of Polylactides and Stereocomplex 261
Jasim Ahmed

12.1 Introduction 261

12.2 PLA and its Isomers 262

12.3 Thermal Property Measurement 263

12.4 Glass Transition Temperatures 263

12.5 Melting Behavior of PLA 267

12.6 Thermal Properties of Stereocomplexed Polylactides 269

12.7 Crystallinity of PLA 272

12.8 Conclusions 276

References 276

13 Thermal Properties of Gelatin and Chitosan 281
Mehraj Fatema Mullah, Linu Joseph, Yasir Ali Arfat and Jasim Ahmed

13.1 Introduction 281

13.2 Thermal Properties of Gelatin 283

13.3 Thermal Properties of Gelatin-Based Film 287

13.4 Thermal Transition by TGA 290

13.5 Thermal Properties of Chitosan 293

13.6 Conclusion 298

References 299

14 Protein Characterization by Thermal Property Measurement 305
A. Seenivasan and T. Panda

14.1 Introduction 305

14.2 Differential Scanning Calorimeter (DSC) 306

14.3 Isothermal Titration Calorimetry 342

14.4 Differential Scanning Fluorimetry (DSF)/Thermal Shift Assay 363

14.5 Thermogravimetric Analysis (TGA) 369

14.6 Differential Thermal Analysis (DTA) 370

14.7 Thermomechanical Analysis (TMA) 371

14.8 Dynamic Thermo-Mechanical Analysis (DMA) 371

14.9 Thermal Conductivity 372

14.10 Conclusion 373

14.11 Future Prospective of Thermal Methods of Characterization 373

References 374

15 High-PressureWater-Ice Transitions in Aqueous and Food Systems 393
Su Guangming, Zhu Songming and Ramaswamy H. S.

15.1 Introduction 393

15.2 Water-Ice Transitions Under High Pressure 394

15.3 High-Pressure Freezing 396

15.4 High-Pressure Thawing 408

15.5 Principle of High-PressureThawing 408

15.6 Effect of HPT on Quality of Selected Foods 415

15.7 HPT on Microbial Growth 418

References 419

16 Pasting Properties of Starch: Effect of Particle Size, Hydrocolloids and High Pressure 427
Jasim Ahmed and Linu Thomas

16.1 Introduction 427

16.2 Pasting Properties 428

16.3 Rheological Measurement 430

16.4 Starch Pasting Cell 430

16.5 Effect of Hydrocolloids and Emulsifiers on Pasting Properties of Starch 437

16.6 Effect of Particle Size on Pasting Properties of Flour Rich in Starch 438

16.7 Effect of Drying on Pasting Properties 442

16.8 Effect of High Pressure on Pasting Properties 445

16.9 Pasting Properties of Blends of Starches 446

16.10 Conclusions 448

References 448

Index 453