SENSORY EVALUATION PR ACTICES Third Edition Food Science and Technology International Series Series Editor Steve L Taylor University of Nebraska Advisory Board Ken Buckle University of New South Wales, Australia Bruce Chassy University of Illinois, USA Patrick Fox University College Cork, Republic of Ireland Dennis Gordon North Dakota State University, USA Robert Hutkins University of Nebraska, USA Ronald Jackson Quebec, Canada Daryl B Lund Cornell University, USA Connie Weaver Purdue University, USA Howard Zhang Ohio State University, USA A complete list of books in this series appears at the end of this volume Sensory Evaluation Practices Third Edition Herbert Stone and Joel L Sidel Tragon Corporation 365 Convention Way Redwood City, California, USA This book is printed on acid-free paper Copyright © 2004 Elsevier (USA) All rights reserved No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher Permissions may be sought directly from Elsevier’s Science and Technology Rights Department in Oxford, UK: phone: (ϩ44) (0) 1865 843830; fax: (ϩ44) (0) 1865 853333; e-mail: permissions@elsevier.co.uk You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting ‘Customer Support’ and then ‘Obtaining Permissions’ Elsevier Academic Press 525 B Street, Suite 1900 San Diego, California 92101-4495, USA http://www.elsevier.com Elsevier Academic Press 84 Theobald’s Road, London WC1X 8RR, UK http://www.elsevier.com Library of Congress Catalog Number: 2003115958 British Library Cataloguing in Publication Data Sensory evaluation practices – 3rd ed (Food science and technology International series) Food – Sensory evaluation Sensory evaluation I Stone, Herbert II Sidel, Joel L 664Ј.072 ISBN 0-12-672690-6 Typeset by Newgen Imaging Systems (P) Ltd, Chennai, India Printed and bound in Hong Kong 04 05 06 07 08 Contents Foreword Preface, First Edition Preface, Second Edition Preface, Third Edition About the Authors Introduction to Sensory Evaluation I II III IV V 11 13 16 The Organization and Operation of a Sensory Evaluation Program 21 I Introduction II Organizing a Sensory Evaluation Program III Conclusions 21 24 66 Measurement 69 Introduction Components of Measurement: Scales Selected Measurement Techniques Conclusions 69 71 87 96 Test Strategy and the Design of Experiments 99 I II III IV V VI VII Introduction and Objective Historical Background Development of Sensory Evaluation Defining Sensory Evaluation A Physiological and Psychological Perspective I II III IV vii ix xi xiii xv Introduction Test Request and Objective Product Criteria Psychological Errors Statistical Considerations Experimental Design Considerations Selected Product Designs 99 101 102 104 111 134 137 Discrimination Testing 145 I Introduction II Methods 145 149 vi Contents III Components of Testing IV Special Problems V Summary 156 195 199 Descriptive Analysis 201 I II III IV Introduction Test Methods Applications for Descriptive Analysis Conclusions 201 211 242 244 Affective Testing 247 I II III IV V VI Introduction Methods Subjects Types of Acceptance Testing Special Problems Conclusions 247 251 259 262 272 277 Special Problems 279 I II III IV V VI VII VIII IX Introduction Instrument–Sensory Relationships Experts and Expert Panels Perceived Efficacy and Advertising Claims Stability Testing Product Development Quality Control Optimization Conclusions 279 281 287 290 295 301 312 325 335 Epilogue 337 I Introduction II Education and the Sensory Professional III The Future 337 339 343 References Index 345 365 Foreword Sensory evaluation over the last 60 years has grown from an emerging area of inquiry, confined to relatively simple quality control applications in a few food organizations, to one which is considered an essential component of the research and development process in food and non-food entities throughout the world This growth has been reflected in the formation and increasing membership of sensory professional organizations and in sensory related presentations at national and international meetings; as well as in the emergence of sensory related journals Naturally this growth has been accompanied by an increase in the number of individuals who are employed in sensory positions, and who have the necessary skills and knowledge As a result, many working in this field depend on core texts such as this one to enhance their working knowledge base The first and second editions of Sensory Evaluation Practices contributed admirably to help fill this knowledge gap both as a reference and as a textbook in educational institutions This text was specifically designed to give practical guidance on sensory procedures that could be directly applied to the sensory issues encountered in a working environment The third edition updates the methods of sensory evaluation and in addition gives test design and organizational guidelines This information can further enhance the sensory professional in performing their responsibilities at a higher level of competence The authors bring to this endeavor over 35 years of experience in dealing with the “real” problems of product development and quality control in both the food and non-food area I appreciate the invitation to write a foreword to this book and am confident that the reader will find that Sensory Evaluation Practices, Third Edition will contribute in a meaningful way to their development as a sensory professional Howard G Schutz Professor Emeritus of Consumer Sciences Food Science & Technology Department University of California at Davis Preface, First Edition There has long been a need for guidance in the development and application of sensory evaluation within the corporate environment The purpose of this book is to provide this guidance and to identify principles and practices that will result in increased utilization of sensory evaluation In recent years, there has been a considerable increase in the number of individuals working in the field who lack the necessary academic training or practical skills for sensory evaluation Published guides have described test methods and suggested procedures for the analysis of results from sensory tests, but have not provided the rationale behind the selection of a particular procedure or test method This book addresses this and other equally important gaps in the field, including the organization and operation of a testing program, the design of a test facility, recommended procedures for the selection, screening, and qualifying of subjects, and the communication of actionable results We have drawn heavily from our more than two decades of research and consulting in this field To our knowledge, no other book provides such an extended coverage of the topic With regard to sensory evaluation, this book expounds a particular philosophy that can best be described as one that places greatest emphasis on the concepts of planning and decision analysis in the broadest sense For the sensory professional, the ability to provide test services should not be considered the primary goal but rather a resource that can be used if a problem warrants it With each request, the sensory evaluation professional must decide how best to meet the needs of the requestor and what methods to apply to the problem Considerable emphasis is placed on the quality of the information derived from a test It is also important to have sufficient behavioral and statistical knowledge to understand the nature of a problem, to ensure that the experimental design is appropriate to the test objective, to understand results, and to communicate them in an actionable way The book is organized into three main parts Chapters and trace the development of the field and define sensory evaluation: what it does, how, where, and for whom Chapters and address the more fundamental issues of measurement, psychological errors in testing, and statistics and experimental design Chapters 5–7 provide the reader with a detailed description of the three classes of test methods (discrimination, descriptive, affective), criteria used to select a specific method, and suggested procedures for data analysis and the interpretation of results A final chapter x Preface, First Edition and epilogue focus on a series of problems that require substantive sensory evaluation involvement: for example, storage testing, measurement of perceived efficacy, correlation of instrumental and sensory data, and systems for product optimization To the extent possible, pertinent literature has been referenced and discussed However, this book is not intended as a review of the literature In those sections with few references, the authors have drawn on their extensive experience to describe a recommended procedure or practice For example, there is little or no published information on the design of a test facility, and the authors’ experience was used to develop the enclosed diagrams and to assist the sensory professional in this endeavor The book is intended for sensory professionals, technical managers, product development and production specialists, and research directors considering the establishment of a program or anticipating expansion of existing resources Marketing, marketing research, and advertising professionals will also benefit from the information in this book The increased interaction between the technologist formulating the product and those responsible for marketing the product requires a greater awareness of sensory evaluation by everyone concerned Individuals considering sensory evaluation as a career will also benefit from reading selected chapters of this book In particular, Chapters 1, 3, 4, and will provide both an overall perspective and specific examples of sensory evaluation applications in business For the entry-level professional or the undergraduate taking a first course in sensory evaluation, Chapters and provide an introduction to the topic, while Chapters 5–7 describe the various test methods For experienced individuals seeking to expand their perspective, Chapters 3, 4, and will be especially helpful Numerous individuals and companies directly and indirectly provided assistance in the development of the ideas expressed in this book as well as the opportunity to put these ideas into practice In particular, we wish to acknowledge the contributions of Jean Eggert of Kraft, Inc.; Robert Boone, Carole Vohsen, and Geralyn Basinski of Ralston Purina; Emer Schaefer of S.C Johnson & Son, Inc.; Daryl Schaller, Jan Michaels, and Jean Yamashita of the Kellogg Company; Robert Brieschke and Lenore Ryan of Kimberly-Clark Corporation; Kaye Zook of the Quaker Oats Company; Margaret Savoca of R.J Reynolds Tobacco Co.; Jan Detwiler of Olympia Brewing Co.; and Erik von Sydow of Nordreco AB Our associates also provided thoughts and assistance at various times In particular, we wish to acknowledge the contributions of Jean Bloomquist of our staff; Professors Rose Marie Pangborn, Edward B Roessler, and Howard Schutz of the University of California at Davis; Birgit Lundgren of the Swedish Food Institute; and Dr Richard Singleton of SRI International We wish to express our appreciation to Marjorie Sterling-Stone who typed many of the drafts of this book and provided the comments needed to make it a more understandable text Special thanks are due to Raymond Andersen who prepared the graphics Herbert Stone also wishes to acknowledge the intellectual support and guidance provided by the late Professor George F Stewart, who through the years encouraged him in this effort Herbert Stone Joel L Sidel 364 References Winn, R L (1988) Touch screen system for sensory evaluation Food Technol 42(11), 68–70 Wolfe, K A (1979) Use of reference standards for sensory evaluation of product quality Food Technol 33(9), 43–44 Woodward, W A and Schucany, W R (1977) Combination of a preference pattern with the triangle taste test Biometrics 33, 31–39 Yandell, B S (1997) ‘Practical Data Analysis for Designed Experiments’, Chapman & Hall, London Young, P T (1961) ‘Motivation and Emotion’, Wiley, New York, NY Zelek, E F., Jr (1990) Legal aspects of sensory analysis Presented at the IFT Annual Meeting and Food Expo, June 16–20, Anaheim, CA Zook, K and Wessman, C (1977) The selection and use of judges for descriptive panels Food Technol 31(11), 56–60 Index Page numbers in italics refer to figures or tables A-not-A procedure, 151 one tailed, 184 Acceptance testing, 35 budgetary and timing considerations, 249 central location tests (CLTs), 263, 264–7 consumer numbers, 273–4 cost effectiveness, 251, 277 “the curse of N”, 273–4 employee v non-employee panels, 260–1 hedonic scaling, home-use tests, 263, 267–71 incomplete designs, 264 laboratory testing, 262–4 methods, see Acceptance testing methods mobile laboratory, 266, 266–7 mobile serving cart, 266, 266 non-employees as subjects, 261–2, 272 panels, 262–3 “piggy-back” tests, 265 practical v statistical significance, 274 preference questioning, 275–6 problems, 272–6 procedures and practices, 277 product variability and, 274 purpose of, 274 questions, sequence of, 276 responsibility for, 249–50 scorecards, 253, 274–5 types of, 262–72 Acceptance testing methods, 251–9 face (smiley) scale, 257–8 hedonic scale, nine-point, 255–6 miscellaneous, 256–9 paired comparison, 252–5 quality scales, 257 Advertising claims, 24, 290–4 consumer testing, 293 legal scrutiny, 293, 294 national taste test claims, 293 product source, 294 test planning and procedures leading to, 292–4 Affective testing in product development, 307–8, 311 replication in, 50, 116–17 see also Acceptance testing Analysis of variance (AOV), 86–7, 123–4 F ratio, 124 in QDA, 223–7, 230 replication and, 123 tests after F test, 124 Anchors, for rating scales products as, 214 word anchors, 79–81, 221, 221–2 Anticipation error, 107 AOV, see Analysis of variance Apprenticeship, in judging product quality, 288 Appropriateness of product for testing, 103 guidelines, 103 Avoidance of extremes, minimizing in QDA, 222 Bipolarity, 256 just-about-right (JAR) scale, 93 nine-point hedonic scale, 90 semantic differential scale, 96 Bonferroni test, 124, 232 Booths, 42, 43, 45 balanced guillotine door, 44, 45, 46 booth time, 40 bread-box door, 44–5, 45 dimensions, 41–6 lighting, 42 location of, 38, 46 number and arrangement of, 37–8, 40 planning, 41–6 in quality control testing, 320 sample pass-through doors, 44 sinks, 41–2 subjects’ access to, 46 ventilation, 44 Brand extensions, 13 Brand management, 25 Business plan, 26 366 Index Canning bees, Capabilities, based on available resources, 23 Carriers, in discrimination testing, 168–70 Category scaling, 70 Central location tests (CLTs), 263, 264–7 Central tendency error, 104–5 Chemical names, use of, 206 Children as subjects, 257–8 use of scales, 83, 89, 90–2 Choice behavior, 148–9 Clinical trials, 291 Color lighting, 42–4, 101 Competition, monitoring of, 24 descriptive analysis and, 243 Computers, see Software Consistency of results, 114 Constant-stimulus method, 194–5 Consumer insights, 31 Consumer testing, 247, 251 guidelines, 250, 293 risks in, 15, 273 Consumers in discrimination testing, 147 qualified/unqualified, 162 unscreened, 162 Contingency coefficient, 75 Contingency table, 75 Contrast errors, 104, 109–10, 306 Control products, in product development, 305, 307, 309–10 Convergence errors, 104, 109–10, 306 Corporate strategy, changing, 29 Cost effectiveness, 15 acceptance testing, 251, 277 Cost reduction, 2, 24, 25 Courses, educational, 10, 12, 340 online, 340 Curve fitting, 86 Cutting bees, Data analysis in descriptive analysis, 210–11 and interpretation in discrimination testing, 174–94 just-about-right (JAR) scale, 93–5, 259 multiple paired tests, 255 in optimization, 327–8, 329–31 paired-comparison test, 253–4 in QDA, 210, 223–35 statements of results, Types and errors, 117–20, 191, 194 TURF, 95, 259 Data processing, 48–9 capabilities, 26 digitizers, 48, 49 direct data entry, 39 satellite system, 38, 49, 49 staff, 34 see also Software Database acceptance testing, 260 in product development, 305, 306, 307, 309, 312 review, 122 Descriptive analysis, 2, 201–45 applications, 242–4 data analysis, 210–11 definition, 202 in the food and beverage industry, 202–3 historical perspective, 202–3 in optimization, 331–2 panel leader’s role, 203, 242 psychological aspect, 207 in quality control monitoring, 322, 324 scorecards, 209, 210–11, 242, 321 subject pool size, 52–3 subject screening, 204–5 subject selection, 203–4 subject training, 205–10 test methods, see Descriptive analysis test methods as type of introspection, 207 Descriptive analysis test methods, 211–42 classification, 211, 211 diagnostic descriptive analysis, 211, 239–42 Flavor Profile, 202–3, 203, 211, 212 Free-Choice profiling, 207–8, 211, 238–9 miscellaneous, 239–42 product experts, 211 Profile Attribute Analysis, 240 QDA, see QDA (Quantitative Descriptive Analysis) qualitative, 211 quantitative, 211 Quantitative Flavor Profiling, 241 Spectrum Descriptive Analysis, 210, 211, 235–8 Texture Profile, 211, 213–15 Descriptive panel, 289 Descriptive profiles, 316–17, 325 Descriptive tests, 35, 50 replication in, 115, 115–16 Diagnostic descriptive analysis, 211, 239–42 Difference-from-reference scale, 298 Difference–preference test, 273 Difference testing, 56–7 and discrimination testing, 147, 148 report form, 65 Digitizers, 48, 49 Discrimination v recognition, 196–7 Discrimination testing, 35, 50, 57–8, 100, 112, 145–200 carriers, 168–70 components of, 156–95 consumer numbers, 147 data analysis and interpretation, 174–94 and difference testing, 147, 148 Index 367 experimental design, 170–4 forced-choice, 149, 184 guidelines, 163–4, 199–200 innate qualities, 199 lighting, 167–8, 195 limitations, 146 management of, 156–7 methods, see Discrimination testing methods miscellaneous, 155 misuse of, 147 no-decision responses, 184 number of subjects per test, 40–1 objectives, 158–9 one-tailed, 184 operational elements, 156–7 organization, 156–7 preference testing after, 147, 196–7 procedures, 10, 159–74 product coding, 170 product preparation and serving, 167 product screening, 159–60 in quality control monitoring, 321–2, 324 record keeping, 156, 164–5 replication in, 115, 185–90 requests for, 158, 158 sensitivity, 160–1 statistical significance tables, 174, 175–83, 184 subject pool size, 52–3 subject selection, 162–6 test selection, 160–2 two-tailed, 184 visual difference, 161–2, 167 Discrimination testing methods, 149–55 directional discrimination, 76 dual-standard method, 155 duo-trio tests, see Duo-trio tests just-noticeable-difference (JND), 193, 194–5, 198 n-AFC, 155 paired-comparison test, 149–51 same-or-different test, 160, 170, 172, 184 sequential analysis, 166 triangle test, see Triangle test Dissimilarity scale, 70 Dual standard method, of discrimination testing, 155 Duncan’s test, 119, 124, 230, 231, 232, 233, 233 Dunnett’s test, 124, 141, 230, 232 Duo-trio tests, 152–3, 171 balanced, 171, 172 constant-reference, 152–3, 161, 171, 173, 192 one tailed, 184 scorecards, 152, 152 Education courses, 10, 12 sensory professionals, 339–43 Efficacy, see Product efficacy Electronic noses and tongues, 59–60, 282, 325 Employee acceptance tests, validity of, 260–1 Employees v non-employees as subjects for acceptance tests, 260–1 see also Staff End-order effects, see Avoidance of extremes Errors in statements of results, Types and errors, 117–20, 191, 194 Errors in testing, 100–1 of anticipation, 107 central tendency error, 104–5 contrast errors, 104, 109–10, 306 convergence errors, 104, 109–10, 306 of expectation, 107 first-sample effect, 104 first-sample error, see Time-order error of habituation, 107 halo effect, 108 leniency error, 108 logical error, 108 order effect error, see Time-order error position error, see Time-order error proximity error, 108–9 psychological, 100, 104–10 stimulus error, 107 time-order error, 105–7 Ethnographics, 303 Expectation error, 107 Experimental design, 134–7 balanced-block designs, 134, 136, 138, 138 balanced-incomplete-block designs, 139, 142 discrimination testing, 170–4 guidelines, 134–6 Expert panels, 288–90 Experts, 6, 8, 287–90 description, 287–8 expert panels, 288–90 judging product quality, 288 v trained panel, 280–1, 288–9 External validity, 114 F ratio, 124 F test, tests after, 124 Face (smiley) scales, 90–2, 257–8 risk of misinterpretation, 257 Face validity, 114 Factor analysis, 210–11 physical/sensory/chemical data, 284–7 Fechner, G T., 17–18 First-sample effect, 104 First-sample error, see Time-order error Fisher’s least significant difference (LSD) test, 124 modified, 232 Flavor evaluation, 146 importance of, 3, Flavor Profile method, 10 collective judgment, 212 of descriptive analysis, 211, 212, 240–1 368 Index Flavor Profile method (continued) development of, 202–3 dilution procedure, 212 panel leader’s role, 212 subject selection/screening, 203, 212 Focus groups, 302–3, 304 information from, 304 Food action rating scale (FACT), 248 Food safety, 3, 312, 325 health and safety regulations, 290 Forced-choice tests, 149, 184 Free-Choice profiling, 207–8, 211, 238–9 use of statistics in, 207 Front-end research, 304 Functional measurement, 83 Future, 343–4 General linear model (GLM) hypothesis, 123 Goals and objectives, 26, 27–9 Graphic rating scale, 83–4, 221 Habituation error, 107 Halo effect, 108, 252, 276 Health and safety regulations, 290 Hedonic continuum, 248 Hedonic scale, nine-point, 82, 87–90, 105, 106, 255–6 bipolarity, 90 criticisms of, 89–90, 256 v magnitude estimation, 255–6 Hedonic scaling, History, 7–10 Home-use tests, 263, 267–71 Imagery, Implementation stage, 30 Ingredients modification, 150 replacement, 32 testing, 323–4 see also Reference products/ingredients Institute of Food Technologists, Sensory Evaluation Division, 3, 13 Instrument–sensory relationships, 281–7 factor analysis, 284–7 physical/chemical/sensory measures, 283, 284 Instruments advantages of, 282 and hedonic response, 282, 283 humans functioning as, imitative, definitions, 281 preference testing and, 282–3 Interval scales, 83–4 Introspection, descriptive analysis as, 207 Jar scale, see Just-about-right (JAR) scale Judgments, independence/dependence of, 117 Just-about-right (JAR) scale, 92–3, 259 bipolarity, 93 data analysis, 93–5, 259 Just-noticeable-difference (JND), 17, 18, 193, 194–5, 198 constant-stimulus method, 194–5 single-stimulus method, 195 Kertosis, 120, 121 Labeled affective magnitude scale (LAMS), 105, 256 Labeled Magnitude Scale (LMS), 87 Laboratory testing, 262–4 mobile laboratory, 266, 266–7 Language, sensory/descriptive development of, 206–7 including references, 210 v subjects’ own terminology, 206, 207 Latin-square design, 105 Law of Comparative Judgment, 19 Least significant difference (LSD) test, 124 modified, 232 Leniency error, 108 Lighting color, 42–4, 101 for discrimination testing, 167–8, 195 Likert scale, 96, 97, 258 Liking asking subjects’ reasons for, 275 measurement of, 248, 276 Line extensions, 302, 308, 309 Line scales, 83–4 in QDA, 221–2 Listening, selective, 304–5 Logical error, 108 McNemar test, 93, 94, 95 Magnitude estimation, 19, 70, 84, 85, 90, 341–2 v nine-point hedonic scale, 255–6 Magnitude-of-difference scoring, in quality control monitoring, 322 Magnitude production, 84 Magnitude scales, 70 labeled affective magnitude scale (LAMS), 105, 256 Labeled Magnitude Scale (LMS), 87 Managers educating, 343 see also Sensory professional-managers Market share, growth in, Marketing research, 15–16 acceptance testing and, 249 paired-comparison test in, 254 Measurement, 69–97 functional, 83 Meat product evaluation, 256 Metathetic continua, 85 Index 369 Motivation of subjects, 59–61 guidelines, 60 Multiple-factor designs and analyses, 125–33 split-plot (mixed) designs, see Split-plot (mixed) designs and analysis treatment-by-treatment-by-subject (T ϫ T ϫ S), 126, 127 treatments-by-subject (T ϫ S), 125–7 Multiple paired tests, 141–3, 254–5 data analysis, 255 Multiple regression/correlation (MR/C) techniques, 326–7, 328, 332 Multiproduct tests, in product development, 306 Multivariate analysis, 342–3 in QDA, 228–30 n-AFC discrimination testing methods, 155 N of 1, see Experts National Advertising Division (NAD), Better Business Bureau concerns referred to, 294 guidelines, 293, 294 National taste test claims, 293 Neural networks, 328, 342–3 Newman–Keuls test, 119, 124, 230, 231, 232 Newspaper articles, 12 Nine-point hedonic scale, see Hedonic scale, nine-point Nominal scales, 73–6 Non-employees, as subjects for acceptance tests, 261–2, 272 v employees, 260–1 Non-parametric statistical methods, 112–13 Noses, electronic, 59–60, 282, 325 Number biases, 5, Objectives, see Goals and objectives Operational strategy, 23 Operations manual, 27, 65–6 Optimization, 325–35 cluster analysis, 332–3 complexity of, 332 consumer questionnaires, 334–5 data analysis, 327–8, 329–31 definition, 326 descriptive analysis in, 331–2 design approaches, literature on, 331–2 objective, 327 process stages, 328, 329 in product development, 311 product selection, 331 types of programs, 326 Usage and Attitude (U&A) data, 334 use of optimization information, 326 Order effect error, see Time-order error Ordinal scales, 76–83 data analysis, 82 interval properties, 81–2 parametric/non-parametric categories, 82 ranking, 76–9 Organization, importance of, 21–2 Organizational plan, 23 Organoleptic analysis, Paired-comparison test, 3, 76, 77, 82–3, 149–51, 252–5 A-not-A procedure, 151 data analysis, 253–4 directional, 149, 150, 171 discrimination testing, 170, 171, 171 dislike both equally, 252, 254 in marketing research, 254 no preference option, 252, 253–4 paired eating method, 151 Paired-eating method, 151 Paired-preference data v scaled data, 271 Paired-preference test, 76, 82, 92 scorecard, 253 Paired same-or-different test, 170, 172 Panels acceptance testing, 262–3 compared, 289–90 employee v non-employee, in acceptance testing, 260–1 trained v expert, 280–1, 288–9 Parametric statistical methods, 112–13 Partial least squares (PLS), 327 Perceptions, phantom, 58, 107 Performance monitoring, of subjects, 26, 59–61 Personal care products, frequency of application, 292 Phantom attribute, 107, 210 Phantom perceptions, 58, 107 Physical/chemical-sensory relationships, descriptive analysis and, 244 Physiological perspective, 16–19 neural pathways, 16 sense receptors, 16 Planning, 24, 27, 30, 66 business plan, 26 organizational plan, 23 Planning stage, 30 Position error, see Time-order error Power law, 85 Preference measurement, 248 Preference testing, 247 after discrimination testing, 147, 196–7 paired comparison, 252–5 Preparation area, 46–8 counter space, 47 heating, lighting, ventilation, 47–8 Principal components analysis (PCA), 284, 289 Process/ingredient/analytical/sensory relationships, 24 Procrustes analysis, 239 Product attitude survey (PAS), 54, 163, 164–5 370 Index Product development, 24, 301–12 affective testing, 307–8, 311 control products, 305, 307, 309–10 database, 305, 306, 307, 309, 312 definition, 301 descriptive analysis and, 244 failure rate, 301–2 marketing and sensory testing objectives, 305 multiproduct tests in, 306 new ideas, sources and procedures, 302–3 optimization and, 311 project team, 311 publications featuring, 302 QDA in, 305–6, 309 sequence of events in, 307–11 Product differences, 145–6, 227 description of, 198–9 giving atypical results, 25 magnitude of, 197 Product efficacy biological, 290, 291 perceived, 290–4 Product stability testing, 295–301 determining shelf life, 295–7 difference-from-reference scale, 298 methods, 299–300 planned approach to, 301 product source and, 297 project termination criteria, 300 split-plot analysis, see Split-plot (mixed) designs and analysis use of a control/reference, 297–8, 300 Products appropriateness of, for testing, 103 “bridge products”, 333 changing concepts, 306–7 criteria for testing, 102–3 dating, 295, 301 development of, see Product development differences between, see Product differences efficacy, perceived, 290–4 evaluation of, 5, 202 failure, 13 grading, 314, 315 “ideal”, 310 intrinsic sensory properties, 248 knowledge of, and test strategy, 100–1 numerical codes for, 73, 170 preparation and serving, in discrimination testing, 167 product line extensions, 302, 308, 309 quality index, 318–19 reference products, see Reference products/ ingredients reformulation, 24 scorecards for, see Scorecards screening, in discrimination testing, 159–60 sensory specification, 24 serving order during tests, see Serving order shelf life, 295–7, 301 source of, in product stability testing, 297 stability testing, see Product stability testing variability in, 187, 274 see also Quality control Profile Attribute Analysis, 240 Profitability, contribution towards, 21–2 Program strategy, 26, 29–31 Project team, in product development, 311 Proprietary situation usage surveys, 334 Prothetic continua, 85 Protocepts, 310–11 Proximity error, 108–9 Psychological errors in testing, 100, 104–10 Psychological perspective, 16–19 Psychology, measurement in, 69–70 Psychophysical Law, 17–18, 84–5 Psychophysical Power Law, 18 Psychophysics, 17–19 Public relations activities, 50 Publications, sensory evaluation, 340 QDA (Quantitative Descriptive Analysis), 211, 215–35 consensus language development, 219–20 data analysis, 210, 223–35 describing sensory properties, 216–17 development of, 215–16 discrimination trials in, 204 evaluation of multiple products, 217 features of, 216–35 line scales, 221–2 minimizing end-order effects (avoidance of extremes), 222 panel leader’s role, 205 in product development, 305–6 product difference, 227 quantification, 220–3 reference material, 219 reliability of responses, 222–3 repeated trials, 222–3 sensory maps/pictures (“spider webs”), 234–5, 234, 236–7 subject response behavior, 225, 225–6 subjects limited in number, 218–19 subjects qualified before participation, 218 terminology, 207, 208–9, 217 training, 208, 241 Quality, meaning, 312–13 Quality assurance, 24, 316 Quality control, 24, 312–25 aim, 313 consumer-based, 314 descriptive analysis and, 244 descriptive profiles, 316–17, 325 monitoring, see Quality control monitoring sensory programs’ lack of success, 313–14 variation in products, 312 Index 371 Quality control monitoring descriptive analysis, 322, 324 discrimination testing, 321–2, 324 evaluation frequency, 321 finished product evaluation, 324 go/no-go decisions, 321, 322, 323 guidelines, 320–3 management commitment to, 324–5 manufacturing process, stages appropriate for, 323–4 methods, 321–2 out-of-date systems, 314 product acceptance–rejection criteria, 321 record-keeping and reporting, 323 reference material, 320, 321–2, 325 resources, 319–21 subject performance monitoring, 322 subject screening, 320 subject training, 320–1 testing area, 320 Quality scales, 257 Quality standards, 313, 315, 316 Quantitative Descriptive Analysis, see QDA Quantitative Flavor Profiling, 241 Questionnaires for completion by consumers, 334–5 Questions close-ended, 76 open-ended, 74, 75–6, 252, 274, 275 R-index, 155 Rank-order test, 76 Ranking tests, 76–9 data analysis methods, 78–9 direct, 77 limitations, 77–8 multi-product, 77 Rating scales, 79 data analysis, 82 graphic, 83–4, 221 nine-point, 79 word anchors, 79–81, 221, 221–2 see also Scales Ratio estimation, 84 Ratio production, 84 Ratio scales, 84–7 data analysis, 86–7 magnitude estimation, 84, 85, 86, 341–2 use of (ratio scaling), 70, 85–6, 342 Raw materials sampling, 283 specification, 24 Recognition v discrimination, 196–7 Record keeping discrimination testing, 156, 164–5 in quality control monitoring, 323 test reports, 26, 63–5 see also Performance monitoring; Test requests Reference products/ingredients, 141–3, 219 for quality control tests, 320, 321–2, 325 Reliability, 113–15 of responses in QDA, 222–3 of results, 4, 113–15 Replication, 115–17, 119 additional subjects in place of, 116 in affective testing, 50, 116–17 AOV and, 123 in descriptive tests, 115, 115–16 in discrimination testing, 115, 185–90 in multiple-factor designs and analyses, 125–6 statistical approach to, 116 Request stage, 30, 31 Research, 27, 66 front-end research, 304 Research and development, 25, 26 Response scales, 71 bias and, 72 desirable features, 71–2 ease of use, 71 meaningfulness of, to subjects, 71 pilot test on inauguration of, 73 sensitivity, 72 statistical analysis, 72 validity/relevance, 72 see also Scales Response surface methodology (RSM), 326, 327, 328, 332 Results, reliability and validity, 4, 113–15 Risk in decision-making, Types and errors, 117–20, 191, 194 statistical, 112 Salt, perception of, 148 Same-or-different test, 160, 170, 172 one-tailed, 184 Scaled data v paired-preference data, 271 Scales, 71–87 avoidance of extremes, 105 categories, 73 children using, 83, 89, 90–2 difference-from-reference scale, 298 dissimilarity scale, 70 face (smiley), 90–2, 257–8 five-point, 79, 291 food action rating scale (FACT), 248 hedonic scale, nine-point, see Hedonic scale, nine-point interval, 83–4 just-about-right (JAR) scale, 92–5, 259 labeled affective magnitude scale (LAMS), 105, 256 Labeled Magnitude Scale (LMS), 87 Likert, 96, 97, 258 line scales, 83–4, 221–2 magnitude scale, 70 nominal, 73–6 372 Index Scales (continued) ordinal, 76–83 quality, 257 ratio, see Ratio scales semantic differential, 96, 258 suitability for stated problem, 96–7 three-point, 291 see also Rating scales; Response scales Scaling, multidimensional, 76 Scaling theory, 70 Scheffé test, 119, 124, 230, 232 Scorecards, 5, 9, 108, 109 for acceptance testing, 253, 274–5 for descriptive analysis, 209, 210–11, 242, 321 for directional paired-comparison test, 149, 150 for duo-trio test, 152, 152 for paired-preference test, 253 product quality index, 316–19 simple v multipage, 274–5 for triangle test, 154 Scoring, Semantic differential scale, 96, 258 bipolarity, 96 Sensitivity, of response scales, 72 Sensory analysts, 33–4, 35 Sensory evaluation activities, 24 as applied science, 208 capabilities, 28 courses in, 340 defining, 13–16 development of, 11–13 different views on, 22–3 early developments, 10 early survey, encompassing all senses, 14, 16–17 future, 343–4 goals and objectives, 26, 27–9 greater awareness of, historical background, 7–10 an independent group, 26 location within company, 25–6 misuse of, 338 opportunities for, 12–13 as part of marketing decisions, as profitable investment, 344 publications, 340 reliance on single methods, 11–12 a scientific discipline, 2–3, 4, 11, 13, 208, 339–41 web sites, 340 workshops, 340, 343 Sensory evaluation program elements of, 26–7 organization of, 24–66 Sensory fatigue, 82, 141, 185, 186, 214 Sensory forgetting curve, 163 Sensory information, understanding of, 4–5 Sensory professional-managers, responsibilities, 32 Sensory professionals attributes, 338 duties, 23, 33, 35 education and, 339–43 management skills and, 33 need for, 337–8 Sensory programs impact of, 280 lack of success, 313–14 time to develop, 337 Sensory technicians, 33 Sequential analysis, 68, 166 in subject selection, 58 Serving order, 134–6 directional paired-comparison test, 171 monadic sequential, 117, 125, 136, 168, 195 paired same-or-different test, 172 triangle test, balanced order, 173 duo-trio test, balanced reference, 172 duo-trio test, constant reference, 173 three-product test, 137, 137–8 four-product random test, 135 four-product test, 138, 138 four-product test with replication, 139, 139 five-product test, 139, 140 twelve-product test, 139, 141 Shelf life, 295–7, 301 Signal detection theory, 18, 149, 185 Single-sample presentation, Single-stimulus method, 195 “Sip and spit” procedure, 200 Skewness, 120, 121 Smith’s procedure, 188 Software reliance on standard packages, 1, statistical packages, 124 Spectrum Descriptive Analysis, 210, 211, 235–8 subject training, 235 Split-plot (mixed) designs and analysis, 111, 128–33, 300 one-within and one-between, 128, 129, 260 one-within and two-between, 128, 132–3 two-within and one-between, 128, 130–1 Stability testing, see Product stability testing Staff, professional, 26, 31–6 clerical/data processing, 34, 35 core group, 34 numbers needed, 34, 35, 36 recruiting, 31–2 see also Employees; Sensory analysts; Sensory professional-managers; Sensory professionals; Sensory technicians Statistical considerations, 111–33 database review, 122 external validity, 114 judgments, 117 reliability, 113–15 Index 373 replication, 115–17 risk, 112 risk in decision-making, 117–20 subject selection, 117 Types and errors, 117–20 validity, 113–15 Statistical measures, 120–33 analysis of variance (AOV), see Analysis of variance general linear model (GLM) hypothesis, 123 kertosis, 120, 121 multiple-factor designs and analyses, 125–33 skewness, 120, 121 t-test, 122–3 Statistical methods parametric/non-parametric, 112–13 sequential analysis, 68, 166 Statistical power, 119 Statistical significance tables, discrimination testing, 174, 175–83 Statisticians, delegation to, 111 Statistics computer software packages, 124 factor analysis, 210–11 in Free-Choice profiling, 207 misunderstanding/misuse of, 210 Steven’s Power Law, 85 Stimulus error, 107 Storage stability, 24 Storage testing, descriptive analysis and, 243 Strategic thinking, 23 Structuralism, 207 Stuart–Maxwell test, 93–5 Student’s t distribution, see t-test Subject bias, 52, 260 Subject performance in discrimination testing, 165, 166 quality control monitoring, 322 Subject pool, 26 changing membership, 55 size of, 52 time needed to build up, 52–3 Subject screening, 26, 53, 53–9, 259 for descriptive analysis, 204–5 difference tests, 56–7 discrimination tests, 57–8 multiple product types, 204–5 product category specific, 204 purpose of, 204 for quality control monitoring, 320 screening tests, 53–5 selection of products for, 58 survey forms, 53, 54, 55 threshold tests, 56 Subject selection, 50–3 criteria, 259–60 descriptive analysis, 203–4 discrimination testing, 162–6 sequential analysis, 58 Subject training, 5–6 acceptance testing v discrimination/descriptive testing, 260 activities forming part of, 205 for descriptive analysis, 205–10 descriptive language and, 205 objectives of, 210–11 QDA method, 208, 241 for quality control monitoring, 320–1 references, 209–10 Subject variability, colored lighting and, 42–4 Subjects access to booths, 46 availability of, 38 compensation/rewards, 60, 164, 262, 272 frequency of participation, 39, 51–2, 260 guidelines on working with, 51 motivation, 59–61 motivation guidelines, 60 movements to/from facility, 38, 39 non-employees as, 261–2, 272 performance monitoring, 26, 59–61 pool of, see Subject pool qualified to participate, 51, 56, 58–9, 120, 218 random selection, 117 response behavior, 225, 225–6 screening, see Subject screening selection of, see Subject selection training, see Subject training variability of, 5, 42–5 Sweetness, 11 t-test, 122–3 dependent t formula, 122 paired-variate procedure, 122 Teams, project team in product development, 311 Test facilities, 26, 36–50 booths, see Booths data processing, see Data processing description, 37 design of, 36–7 equipment, 40 individual areas, 39, 47 information base, 37 panel discussion area, 47 preparation area, 46–8 as public relations activity, 50 satellite facilities, 38, 49, 49 space requirements, 37, 38–9, 39, 40, 47 ventilation, 37, 44 working with architect, 37, 41, 44 Test fatigue, 163 Test methods, 50 ability to use, 26 categorization, 50 selecting, 100 see also individual testing methods 374 Index Test requests, 26, 61–3, 101–2 completeness of, 102 discrimination testing, 158, 158 establishment of objectives, 62–3 reasonableness of, 102 rejection of, 102–3 Test selection, discrimination testing, 160–2 Test strategy, 99–101 Testing errors in, see Errors in testing stages in process of, 30 Tests facilities for, see Test facilities increasing volume of, 35–6 methods, see Test methods objectives, 99–100, 102, 158–9 reliability and validity of results, 4, 113–15 reports, 26, 63–5 requests for, see Test requests single-product (monadic) tests, 104 types and distribution, 35, 50 see also individual testing methods Texture analysis, references in, 209 Texture Profile, 211, 213–15 concerns with, 214–15 references in, 213–14 textual parameters v popular terms, 213, 214 Threshold testing, 56, 148, 162–3 see also Difference testing Time-order error, 105–7 Tongues, electronic, 59–60, 282, 325 Training, see Education; Subject training Treatment-by-treatment-by-subject (T ϫ T ϫ S) design, 126, 127 Treatments-by-subject (T ϫ S) design, 125–7 with replication, 125–6 source of variance tables, 125–6 Triangle test, 3, 153–5, 160, 171, 174 one tailed, 184 scorecards, 154 serving order, 173 Tukey (a) and (b) tests, 124, 230, 231–2, 232, 233, 233 and errors, 119 TURF analysis, 95, 259 Univariate analysis, 342 US Army Quartermaster Food and Container Institute, Usage and Attitude (U&A) data, 334 Validity, 113–15 external validity, 114 face validity, 114 of response scales, 72 of results, 4, 113–15 Variability in products, 187, 274 in responses, of subjects, 5, 42–5 Visitor access, 39 Web sites, sensory evaluation, 340 Weber, -, 17, 18 Weber–Fechner Law, 17–18 Word anchors, for rating scales, 79–81 Workshops, sensory evaluation, 340, 343 Food Science and Technology International Series Maynard A Amerine, Rose Marie Pangborn, and Edward B Roessler, Principles of Sensory Evaluation of Food 1965 Martin Glicksman, Gum Technology in the Food Industry 1970 Maynard A Joslyn, Methods in Food Analysis, second edition 1970 C R Stumbo, Thermobacteriology in Food Processing, second edition 1973 Aaron M Altschul (ed.), New Protein Foods: Volume 1, Technology, Part A – 1974 Volume 2, Technology, Part B – 1976 Volume 3, Animal Protein Supplies, Part A – 1978 Volume 4, Animal Protein Supplies, Part B – 1981 Volume 5, Seed Storage Proteins – 1985 S A Goldblith, L Rey, and W W Rothmayr, Freeze Drying and Advanced Food Technology 1975 R B Duckworth (ed.), Water Relations of Food 1975 John A Troller and J H B Christian, Water Activity and Food 1978 A E Bender, Food Processing and Nutrition 1978 D R Osborne and P Voogt, The Analysis of Nutrients in Foods 1978 Marcel Loncin and R L Merson, Food Engineering: Principles and Selected Applications 1979 J G Vaughan (ed.), Food Microscopy 1979 J R A Pollock (ed.), Brewing Science, Volume – 1979 Volume – 1980 Volume – 1987 J Christopher Bauernfeind (ed.), Carotenoids as Colorants and Vitamin A Precursors: Technological and Nutritional Applications 1981 Pericles Markakis (ed.), Anthocyanins as Food Colors 1982 George F Stewart and Maynard A Amerine (eds.), Introduction to Food Science and Technology, second edition 1982 Malcolm C Bourne, Food Texture and Viscosity: Concept and Measurement 1982 Hector A Iglesias and Jorge Chirife, Handbook of Food Isotherms: Water Sorption Parameters for Food and Food Components 1982 Colin Dennis (ed.), Post-Harvest Pathology of Fruits and Vegetables 1983 P J Barnes (ed.), Lipids in Cereal Technology 1983 David Pimentel and Carl W Hall (eds.), Food and Energy Resources 1984 376 Food Science and Technology: International Series Joe M Regenstein and Carrie E Regenstein, Food Protein Chemistry: An Introduction for Food Scientists 1984 Maximo C Gacula, Jr., and Jagbir Singh, Statistical Methods in Food and Consumer Research 1984 Fergus M Clydesdale and Kathryn L Wiemer (eds.), Iron Fortification of Foods 1985 Robert V Decareau, Microwaves in the Food Processing Industry 1985 S M Herschdoerfer (ed.), Quality Control in the Food Industry, second edition Volume – 1985 Volume – 1985 Volume – 1986 Volume – 1987 F E Cunningham and N A Cox (eds.), Microbiology of Poultry Meat Products 1987 Walter M Urbain, Food Irradiation 1986 Peter J Bechtel, Muscle as Food 1986 H W.-S Chan, Autoxidation of Unsaturated Lipids 1986 Chester O McCorkle, Jr., Economics of Food Processing in the United States 1987 Jethro Japtiani, Harvey T Chan, Jr., and William S Sakai, Tropical Fruit Processing 1987 J Solms, D A Booth, R M Pangborn, and O Raunhardt, Food Acceptance and Nutrition 1987 R Macrae, HPLC in Food Analysis, second edition 1988 A M Pearson and R B Young, Muscle and Meat Biochemistry 1989 Dean O Cliver (ed.), Foodborne Diseases 1990 Marjorie P Penfield and Ada Marie Campbell, Experimental Food Science, third edition 1990 Leroy C Blankenship, Colonization Control of Human Bacterial Enteropathogens in Poultry 1991 Yeshajahu Pomeranz, Functional Properties of Food Components, second edition 1991 Reginald H Walter, The Chemistry and Technology of Pectin 1991 Herbert Stone and Joel L Sidel, Sensory Evaluation Practices, second edition 1993 Robert L Shewfelt and Stanley E Prussia, Postharvest Handling: A Systems Approach 1993 R Paul Singh and Dennis R Heldman, Introduction to Food Engineering, second edition 1993 Tilak Nagodawithana and Gerald Reed, Enzymes in Food Processing, third edition 1993 Dallas G Hoover and Larry R Steenson, Bacteriocins 1993 Takayaki Shibamoto and Leonard Bjeldanes, Introduction to Food Toxicology 1993 John A Troller, Sanitation in Food Processing, second edition 1993 Ronald S Jackson, Wine Science: Principles and Applications 1994 Harold D Hafs and Robert G Zimbelman, Low-fat Meats 1994 Lance G Phillips, Dana M Whitehead, and John Kinsella, Structure-Function Properties of Food Proteins 1994 Robert G Jensen, Handbook of Milk Composition 1995 Yrjö H Roos, Phase Transitions in Foods 1995 Reginald H Walter, Polysaccharide Dispersions 1997 Gustavo V Barbosa-Cánovas, M Marcela Góngora-Nieto, Usha R Pothakamury, and Barry G Swanson, Preservation of Foods with Pulsed Electric Fields 1999 Food Science and Technology: International Series 377 Ronald S Jackson, Wine Science: Principles, Practice, Perception, second edition 2000 R Paul Singh and Dennis R Heldman, Introduction to Food Engineering, third edition 2001 Ronald S Jackson, Wine Tasting: A Professional Handbook 2002 Malcolm C Bourne, Food Texture and Viscosity: Concept and Measurement, second edition 2002 Benjamin Caballero and Barry M Popkin (eds), The Nutrition Transition: Diet and Disease in the Developing World 2002 Dean O Cliver and Hans P Riemann (eds), Foodborne Diseases, second edition 2002 Martin Kohlmeier, Nutrient Metabolism 2003 ... Library Cataloguing in Publication Data Sensory evaluation practices – 3rd ed (Food science and technology International series) Food – Sensory evaluation Sensory evaluation I Stone, Herbert II Sidel,... Development of Sensory Evaluation 11 III Development of Sensory Evaluation It would be difficult to identify any one or two developments that were directly responsible for the emergence of sensory evaluation. .. technology As the definition implies, sensory evaluation involves the measurement and evaluation of the sensory properties of foods and other materials Sensory evaluation also involves the analysis