Analytical Methods for Food and Dairy Powders
1. Auflage März 2012
248 Seiten, Hardcover
Wiley & Sons Ltd
Food and dairy powders are created by dehydrating perishable produce, such as milk, eggs, fruit and meat, in order to extend their shelf life and stabilise them for storage or transport. These powders are in high demand for use as ingredients and as food products in their own right, and are of great economic importance to the food and dairy industry worldwide. Today, the ability to control food and dairy powder quality is a source of key competitive advantage. By varying the dehydration process design, and by controlling the technological and thermodynamic parameters during dehydration, it is possible for manufacturers to engineer the biochemical, microbiological and physical characteristics of the food powder to meet their specific product requirements.
This book provides an overview of the existing, adapted or new techniques used to analyse safety and quality in modern food and dairy powders. Based on original research by the authors, the book uses 25 commercial dairy and non-dairy powders to illustrate a range of biochemical and physical methods used to evaluate and characterise powdered food products. Written from a practical perspective, each chapter focuses on a particular analytical technique, outlining the purpose, definition and principle of that method. The authors guide the reader through all of the instruments needed, the safety measures required, and the correct procedures to follow to ensure successful analysis. Instructions on accurate measurement and expression of results are included, and each chapter is richly illustrated with original data and worked examples.
Analytical Methods for Food and Dairy Powders is a unique step-by-step handbook, which will be required reading for anyone involved in the development and manufacture of powdered food products. Food and dairy scientists based in industry will find it essential for new product development and improved quality control, while researchers in the laboratory will especially value the new techniques it comprises.
Chapter 1 Dehydration Processes and their Influence on Powder Properties 1
1.1. Overview of operations 2
1.2. Properties of dehydrated products 20
1.3. Bibliography 41
Chapter 2 Determination of Dry Matter and Total Dry Matter 45
2.1. Determination of free moisture or dry matter 46
2.2. Determination of total moisture or total dry matter 50
2.3. Bibliography 57
Chapter 3 Determination of Nitrogen Fractions 59
3.1. Determination of the total nitrogen content (Kjeldahl method) 60
3.2. Determination of the nitrogen content soluble at pH 4.60 69
3.3. Determination of the non-protein nitrogen content 76
3.4. Determination of non-denatured whey protein nitrogen in skimmed milk powder 82
3.5. Protein nitrogen conversion factors based on amino acid composition in the case of milk and soy 85
3.6. Bibliography 90
Chapter 4 Determination of the Rate of Lactose Crystallisation 93
4.1. Definitions 94
4.2. Principle 95
4.3. Expression of results 95
4.4. Remarks 95
4.5. Examples 96
4.6. Bibliography 96
Chapter 5 Determination of Total Fat and Free Fat Content 99
5.1. Determination of total fat content 100
5.2. Determination of free fat content 107
5.3. Bibliography 111
Chapter 6 Determination of the Ash Content 113
6.1. Definitions 114
6.2. Principle 114
6.3. Instruments and glassware 114
6.4. Personal protection 114
6.5. Procedure 114
6.6. Expression of results 116
6.7. Precision values 116
6.8. Examples 116
6.9. Bibliography 118
Chapter 7 Determination of Particle Size and Friability 119
7.1. Definition 119
7.2. Principle 119
7.3. Methods 120
7.4. Reagents and other products 120
7.5. Instruments and glassware 120
7.6. Personal protection 121
7.7. Procedure 121
7.8. Expression of results 121
7.9. Remarks 123
7.10. Precision values 124
7.11. Examples 125
7.12. Bibliography 127
Chapter 8 Determination of Flowability and Floodability Indices 129
8.1. Definition 129
8.2. Principle 130
8.3. Reagents and other products 130
8.4. Instruments and glassware 130
8.5. Procedure 132
8.6. Expression of results 137
8.7. Remarks 137
8.8. Precision values 140
8.9. Examples 140
8.10. Bibliography 143
Chapter 9 Determination of Density, Interstitial Air Content and Occluded Air Content 145
9.1. Definition 146
9.2. Principle 146
9.3. Methods 146
9.4. Equipment and glassware 147
9.5. Safety 147
9.6. Procedure 147
9.7. Expression of results 148
9.8. Remarks 149
9.9. Precision values 151
9.10. Examples 151
9.11. Bibliography 154
Chapter 10 Determination of Colour and Appearance 155
10.1. Determination of colour 155
10.2. Determination of the presence of scorched particles 161
10.3. Bibliography 164
Chapter 11 Determination of the Sorption Isotherm, Water Activity and Hygroscopicity of Powders 167
11.1. Determination of water activity 168
11.2. Determination of the sorption isotherm 173
11.3. Determination of hygroscopicity 184
11.4. Bibliography 189
Chapter 12 Determination of Glass Transition Temperature Range 191
12.1. Definition 191
12.2. Principle 192
12.3. Methods 192
12.4. Instruments and glassware 193
12.5. Personal protection 194
12.6. Procedure 194
12.7. Expression of results 195
12.8. Remarks 196
12.9. Precision values 198
12.10. Examples 198
12.11. Bibliography 201
Chapter 13 Determination of Rehydration Ability 203
13.1. Determination of wettability 204
13.2. Determination of dispersibility 207
13.3. Determination of solubility 209
13.4. Bibliography 215
Chapter 14 Summary and General Conclusion 217
Index 227
A colour plate section falls between pages 156 and 157
