Sensory Evaluation

Dr Sarah E. Kemp was formerly Head of Global Sensory and Consumer Guidance, Cadbury Schweppes plc, Reading, UK. Dr Tracey Hollowood is Associate Director: Sensory and Consumer Research, Sensory Dimensions Ltd, Bulwell, Nottinghamshire, UK. Dr Joanne Hort is Associate Professor in Sensory Science, Nottingham University, UK.

Preface vii Author biographies ix

Acknowledgements xi

1 Introduction 1

1.1 What is sensory evaluation? 1

1.2 What is the role of sensory evaluation? 2

1.3 What drives successful sensory testing? 3

2 Sensory perception 4

2.1 The human senses 4

2.2 Factors affecting sensory measurements 6

3 Planning your sensory project 11

3.1 Setting objectives 11

3.2 Product type 11

3.3 Budget 12

3.4 Timings 12

3.5 Selecting the test method 12

3.6 Setting action standards 13

3.7 Experimental design 14

3.8 Data analysis 19

4 Requirements for sensory testing 30

4.1 Professional conduct in sensory testing: health, safety, ethical and legal considerations 30

4.2 Good working and laboratory practices 37

4.3 Resources needed for sensory testing 41

4.4 Samples 49

4.5 Assessors 54

4.6 Data capture 63

5 Sensory test methods 66

5.1 Selecting the test 66

5.2 Discrimination tests 66

5.3 Descriptive analysis tests 96

5.4 Affective/consumer tests 118

5.5 Linking consumer, sensory and product data 136

6 Completing the project 138

6.1 Reporting 138

6.2 Documentation and data storage 140

6.3 Dos and don’ts 141

7 Appendices 142

Appendix 1: Examples of Latin Square and Williams Latin Square designs for selected number of samples 142

Appendix 2: IFST PFSG professional code of conduct for sensory professionals 143

Appendix 3: Critical values table for triangle test 147

Appendix 4: Critical values table for duo-trio test and paired comparison test for difference (one tailed) 149

Appendix 5: ANOVA explained 151

Appendix 6: Critical values table for chi-squared 156

Appendix 7: Critical values table for paired comparison and paired difference test (two tailed) 157

Appendix 8: Critical values table for Friedman test 159

Appendix 9: Types of scales 160

Appendix 10: Case study: modified quantitative descriptive analysis of chocolate texture 163

Appendix 11: R index explained 174

8 Glossary 178

9 References 185

Index 189