Probiotic Ice Cream

Dr. Aziz Homayouni-Rad, Professor in Food Science and Technology, Tabriz University of Medical Sciences, Tabriz, Iran. Dr. Homayouni-Rad is a food technologist carrying out research on functional probiotic foods. He has established several studies from molecular identification of probiotic microorganisms to selection, industrial production, delivery vehicles, and clinical study of mentioned beneficial bacteria on human health. He also has expertise on probiotic microencapsulation techniques as well as formulation of probiotic foods and supplements.

Preface xv

Biography xvii

Part I The Science of Probiotic Ice Cream 1

1 Ice Cream and Frozen Dairy Desserts: Classification and History 3

1.1 History of Ice Cream Making 3

1.2 Definition of Ice Cream 4

1.3 Classification of Ice Cream 5

1.3.1 Regular Ice Cream Types 8

1.3.2 Chocolate Ice Cream 10

1.3.3 Fruit Ice Cream 11

1.3.4 Nutty Ice Cream 12

1.3.5 Yoghurt Ice Cream 13

1.3.6 Puddings 15

1.3.7 Special Ice Creams 16

1.3.8 Other Types of Ice Cream 18

References 22

2 Probiotics: Definition and Characterization 23

2.1 Introduction 23

2.2 Definition of Probiotics 25

2.3 Types of Probiotics 28

2.3.1 Lactobacillus Genus 29

2.3.1.1 Lactobacillus acidophilus 31

2.3.1.2 Lactobacillus casei 31

2.3.2 Genus Bifidobacterium 32

2.3.2.1 Bifidobacterium lactis 33

2.3.2.2 Bifidobacterium longum 34

2.3.3 Other Lactic Acid Bacteria 34

2.3.4 Nonlactic Acid Bacteria Probiotics 34

2.3.5 Probiotic Yeasts 34

2.4 Health-Promoting Effects of Probiotics 34

2.5 Necessity of Formulating Probiotic Ice Creams 35

2.6 Challenges in Production, Preservation, and Consumption of Probiotic Ice Cream 36

References 38

3 Selection of Appropriate Probiotic Strains for Use in Probiotic Ice Cream 39

3.1 Selection of Appropriate Probiotic Strains for Use in Probiotic Ice Cream 39

3.2 Effect of pH on Growth and Viability of Probiotics in Culture Media 40

3.3 Effect of Different Sucrose Concentrations on the Growth and Viability of Bacteria in the Culture Medium 46

3.4 Effect of Oxygen Scavengers on the Growth Index of Probiotics in the Culture Medium 53

3.5 Effect of Different Processing Temperatures on the Viability Index of Probiotics in the Culture Medium 57

3.6 Selecting Resilient Probiotic Species for Use in Ice Cream 63

3.7 Review of Researches on the Production of Functional Ice Cream 63

3.8 Investigating the Effects of Microencapsulation on the Viability of Probiotics in Various Food Products, Including Ice Cream 64

References 66

4 Physical Protection of Probiotics in Ice Cream Conditions 67

4.1 Encapsulation of Probiotic Bacteria for Use in Ice Cream 67

4.2 Encapsulation 69

4.2.1 Applications of Microencapsulation 70

4.2.2 Materials Used in Microencapsulation 72

4.2.2.1 Calcium Alginate 73

4.2.2.2 Resistant Starch 75

4.2.3 Methods of Encapsulation 77

4.2.3.1 Spray Drying Encapsulation 79

4.2.3.2 Centrifugal Nozzle Spraying Encapsulation 79

4.2.3.3 Emulsification-based Encapsulation 81

References 84

5 Nutritional Value of Functional Ice Cream 85

5.1 Nutritional Value of Ice Cream 85

5.1.1 Energy Content of Ice Cream 86

5.1.2 Caloric Content of Ice Cream 87

5.1.3 Protein Content in Ice Cream 89

5.1.4 Fat Content in Ice Cream 90

5.1.5 Carbohydrate Content in Ice Cream 90

5.1.6 Mineral Content in Ice Cream 92

5.1.7 Vitamins in Ice Cream 93

5.1.8 Digestibility of Ice Cream 93

References 94

Part II The Technology of Probiotic Ice Cream 95

6 Probiotic Ice Cream (Definition, Formulation, and Characterization) 97

6.1 Definition of Probiotic Ice Cream 97

6.2 Design of Probiotic Ice Cream 98

6.3 Probiotic Ice Cream Characterization 98

6.4 Technology of Probiotic Ice Cream Production 99

6.5 Adding Free and Microencapsulated Probiotic Bacteria into the Ice Cream 101

References 104

7 Prebiotic Ice Cream (Definition, Formulation, and Characterization) 105

7.1 Definition of Prebiotic Ice Cream 105

7.2 Prebiotics 105

7.2.1 Classifications of Prebiotics 106

7.2.1.1 Lactulose 106

7.2.1.2 Lactosaccharose 107

7.2.1.3 Isomalto-oligosaccharides 108

7.2.1.4 Xylo-oligo-saccharides 108

7.2.1.5 Fructo-oligosaccharides 109

7.2.1.6 Galacto-oligosaccharides 109

7.2.1.7 Soy Oligosaccharides 111

7.2.1.8 Resistant Starch 111

7.2.1.9 Dietary Fiber 112

7.3 Design of Prebiotic Ice Cream 113

7.4 Prebiotic Ice Cream Characterization 113

7.5 Technology of Prebiotic Ice Cream Production 114

References 115

8 Synbiotic Ice Cream (Definition, Formulation, and Characterization) 117

8.1 Definition of Synbiotic Ice Cream 117

8.2 Design of Synbiotic Ice Cream 118

8.3 Synbiotic Ice Cream Characterization 118

8.4 Technology of Synbiotic Ice Cream Production 118

References 120

9 Postbiotic Ice Cream (Definition, Formulation, and Characterization) 121

9.1 Definition of Postbiotic Ice Cream 121

9.2 Postbiotics 122

9.3 Design of Postbiotic Ice Cream 122

9.4 Postbiotic Ice Cream Characterization 123

9.5 Technology of Postbiotic Ice Cream Production 123

References 124

10 Functional Ice Cream (Ingredients and Processing) 127

10.1 Ice Cream Composition and Formulation 127

10.1.1 Total Solid Ingredients 127

10.1.2 Milk Fat 128

10.1.3 Milk Solids-Non-fat (MSNF) 130

10.1.4 Sweeteners 132

10.1.5 Stabilizers 133

10.1.6 Emulsifiers 138

10.1.7 Flavors and Colors 140

10.1.8 Water Content and Gases in Ice Cream 141

10.1.9 Optional Ingredients and Components in Ice Cream Formulation 141

10.2 Stages of Ice Cream Production 142

10.2.1 Mix Calculations 142

10.2.2 Preparing Ice Cream Mixture 147

10.2.3 Homogenization 148

10.2.4 Pasteurization 152

10.2.5 Aging of Mix 155

10.2.6 Aeration, Freezing, Packaging, and Hardening 156

References 169

11 Ice Cream as a Probiotic/Prebiotic Delivery Vehicle 171

11.1 Ice Cream as a Probiotic/Prebiotic Delivery Vehicle 171

11.2 Challenges Toward Adding Probiotics into Ice Cream 174

References 177

Part III Quality Control 179

12 Physicochemical, Rheological, and Microbial Properties of Probiotic Ice Cream 181

12.1 The Properties of Probiotic Ice Cream 181

12.2 Physical Properties 182

12.2.1 Surface Tension and Interfacial Tension 182

12.2.2 Stability 183

12.2.3 Density 184

12.2.4 Acidity 184

12.2.5 Surface Adsorption 185

12.2.6 Freezing Point 185

12.2.7 Ice Cream Melting Rate 185

12.2.8 Aeration Capability 187

12.3 Chemical Properties 187

12.3.1 Gel Formation 187

12.3.1.1 Gel Formation in Ice Cream 188

12.4 Rheological Properties 189

12.4.1 Apparent and True Viscosity 189

12.4.2 Determination of Rheological Properties 190

12.4.3 Factors Affecting the Viscosity of Ice Cream mix 192

12.4.4 Methods for Evaluating Ice Cream Mix Viscosity 192

12.4.5 Application of Mixture Viscosity in Freezer Design and Prediction of Final Product Quality 193

12.5 Microbial Properties of Ice Cream 193

12.6 Ice Cream Microstructure 194

12.6.1 Observation of Ice Cream Microstructure 195

12.6.2 Determination of Fat Structure in Ice Cream 195

12.6.3 Analysis of Images Obtained from Ice Cream Microstructure 196

12.7 Quality Control of Ice Cream in Practice 198

12.7.1 Physicochemical Controls 199

12.7.1.1 Measurement of Moisture and Dry Matter in Ice Cream 199

12.7.1.2 Measurement of Ice Cream Acidity 200

12.7.1.3 Measurement of Ice Cream Overrun 200

12.7.1.4 Measurement of Ice Cream Fat Percentage 201

12.7.1.5 Identification of the Type of Fat Used in Ice Cream 201

12.7.1.6 Sucrose Percentage Measurement 203

12.7.1.7 Measurement of MSNF in Ice Cream 203

12.7.2 Microbiological Controls 204

12.7.2.1 Preparation of Various Dilutions from Solid and Liquid Food Materials 205

12.7.2.2 Enumeration of Aerobic Bacteria 206

12.7.2.3 Enumeration of Coliform Bacteria 206

12.7.2.4 Enumeration of E. coli 207

12.7.2.5 Enumeration of Staphylococcus (Staph) 207

12.7.2.6 Enumeration of Mold and Yeast 208

12.7.2.7 Enumeration of Salmonella 208

12.7.2.8 Quantifying Probiotic Microorganisms in Probiotic Ice Cream 209

References 210

13 Sensory Properties of Probiotic Ice Cream 211

13.1 Sensory Evaluation of Ice Cream 211

13.1.1 Sensory Evaluation of Probiotic Ice Cream 213

13.1.2 Sensory Properties of Probiotic Ice Cream 214

13.2 Examination of Various Aspects of Ice Cream Quality 214

13.2.1 Taste 215

13.2.2 Body 217

13.2.3 Texture 218

13.2.4 Color 219

13.2.5 Appearance 219

13.2.6 Melting 220

13.2.7 Packaging 220

References 221

14 Shelf-Life Evaluation of Probiotic Ice Cream 223

14.1 Ice Cream Shelf Life 223

14.2 Factors Affecting Ice Cream Shelf Life 224

14.2.1 Raw Materials 225

14.2.1.1 Milk 225

14.2.1.2 Cream 226

14.2.1.3 Condensed Milk 226

14.2.1.4 Starter Culture 226

14.2.1.5 Fruits 227

14.2.1.6 Other Raw Materials 227

14.3 Shelf Life of Frozen Foods 227

14.3.1 Effect of Microorganisms 227

14.3.2 Movement of Ice Crystals in Food Systems 228

14.3.3 Physicochemical Reactions 228

14.3.4 Time-Temperature Tolerance (TTT) 229

14.3.5 PPP Factors (Product Quality, Processing, and Packaging) 229

14.3.6 Glass Transition State 229

14.3.7 Knowledge About the Product 230

14.3.8 Targeted Tests 230

14.3.9 Accelerated Tests 230

14.3.10 Cold Chain 231

14.4 Determining Shelf Life in Practice 233

14.4.1 Determining Shelf Life with Storage Tests 233

14.4.2 Ice Cream Shelf Life 234

14.4.2.1 Effect of Temperature Fluctuations and Ice Crystal Recrystallization on Shelf Life 234

14.4.2.2 Role of Stabilizers in Shelf Life 235

14.4.2.3 Role of Communication in Ice Cream Shelf Life 236

14.4.2.4 Methods to Increase Ice Cream Shelf Life 236

References 237

Index 239