Confectionery and Chocolate Engineering

Confectionery and chocolate manufacture has been dominated by large-scale industrial processing for several decades. It is often the case though, that a trial and error approach is applied to the development of new products and processes, rather than verified scientific principles. Confectionery and Chocolate Engineering: Principles and Applications, Second edition, adds to information presented in the first edition on essential topics such as food safety, quality assurance, sweets for special nutritional purposes, artizan chocolate, and confectioneries. In addition, information is provided on the fading memory of viscoelastic fluids, which are briefly discussed in terms of fractional calculus, and gelation as a second order phase transition. Chemical operations such as inversion, caramelization, and the Maillard reaction, as well as the complex operations including conching, drying, frying, baking, and roasting used in confectionery manufacture are also described. This book provides food engineers, scientists, technologists and students in research, industry, and food and chemical engineering-related courses with a scientific, theoretical description and analysis of confectionery manufacturing, opening up new possibilities for process and product improvement, relating to increased efficiency of operations, the use of new materials, and new applications for traditional raw materials.

Autorentext
Ferenc Mohos chaired the Codex Alimentarius Hungaricus Confectionery Products Working Committee for two decades, whilst being Managing Director of his own consulting company, Food Quality 1992 Ltd., Budapest. Presently, he is affiliated with the Szeged University and also the Corvinus University of Budapest, Hungary.

Inhalt

Preface xxiii

Preface to the second edition xxvii

Acknowledgements xxix

Part I: Theoretical introduction

1 Principles of food engineering 3

1.1 Introduction 3

1.2 The Damköhler equations 6

1.3 Investigation of the Damköhler equations by means of similarity theory 8

1.4 Analogies 14

1.5 Dimensional analysis 16

1.6 System theoretical approaches to food engineering 19

1.7 Food safety and quality assurance 21

Further reading 22

2 Characterization of substances used in the confectionery industry 23

2.1 Qualitative characterization of substances 23

2.2 Quantitative characterization of confectionery products 33

2.3 Preparation of recipes 49

2.4 Composition of chocolate confectioneries biscuits and wafers made for special nutritional purposes 56

Further reading 60

3 Engineering properties of foods 61

3.1 Introduction 61

3.2 Density 61

3.3 Fundamental functions of thermodynamics 65

3.4 Latent heat and heat of reaction 71

3.5 Thermal conductivity 76

3.6 Thermal diffusivity and Prandtl number 78

3.7 Mass diffusivity and Schmidt number 81

3.8 Dielectric properties 85

3.9 Electrical conductivity 91

3.10 Infrared absorption properties 95

3.11 Physical characteristics of food powders 96

Further reading 107

4 The rheology of foods and sweets 109

4.1 Rheology: its importance in the confectionery industry 109

4.2 Stress and strain 109

4.3 Solid behaviour 115

4.4 Fluid behaviour 120

4.5 Viscosity of solutions 159

4.6 Viscosity of emulsions 161

4.7 Viscosity of suspensions 164

4.8 Rheological properties of gels 166

4.9 Rheological properties of sweets 171

4.10 Rheological properties of wheat flour doughs 183

4.11 Relationship between food oral processing and rheology 193

Further reading 194

5 Introduction to food colloids 197

5.1 The colloidal state 197

5.2 Formation of colloids 199

5.3 Properties of macromolecular colloids 202

5.4 Properties of colloids of association 208

5.5 Properties of interfaces 210

5.6 Electrical properties of interfaces 219

5.7 Theory of colloidal stability: the DLVO theory 221

5.8 Stability and changes of colloids and coarse dispersions 224

5.9 Emulsion instability 233

5.10 Phase inversion 243

5.11 Foams 245

5.12 Gelation as a second-order phase transition 256

Further reading 261

Part II: Physical operations

6 Comminution 265

6.1 Changes during size reduction 265

6.2 Rittinger's surface theory 266

6.3 Kick's volume theory 267

6.4 The third or Bond theory 268

6.5 Energy requirement for comminution 268

6.6 Particle size distribution of ground products 269

6.7 Particle size distributions 273

6.8 Kinetics of grinding 275

6.9 Comminution by five-roll refiners 276

6.10 Grinding by a melangeur 280

6.11 Comminution by a stirred ball mill 284

Further reading 289

7 Mixing/kneading 290

7.1 Technical solutions to the problem of mixing 290

7.2 Power characteristics of a stirrer 290

7.3 Mixing time characteristics of a stirrer 292

7.4 Representative shear rate and viscosity for mixing 292

7.5 Calculation of the Reynolds number for mixing 292

7.6 Mixing of powders 294

7.7 Mixing of fluids of high viscosity 300

7.8 Effect of impeller speed on heat and mass transfer 301

7.9 Mixing by blade mixers 302

7.10 Mixing rolls 303

7.11 Mixing of two liquids 304 Fu...