VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE AND … · 2013. 7. 17. · F N P PUBLICATIONS IN FOOD SCIENCE AND NUTRITION Books VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE,

VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE AND

CONSUMER PRODUCT TESTING

Howard R. Moskowitz, Ph.D.

Moskowitz Jacobs Inc. White Plains, New York

Alejandra M. Mufioz, M.S.

IRIS: International Resources for Insights and Solutions, LLC

Mountainside, New Jersey

Maximo C. Gacula, Jr., Ph.D.

Department of Psychology Arizona State University

Tempe, Arizona

FOOD & NUTRITION PRESS, INC. TRUMBULL, CONNECTICUT 06611 USA

VIEWPO1,NTS AND CONTROVERSIES IN

SENSORY SCIENCE AND


F N

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Books VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE, H.R. Moskowitz er al. PIONEERS IN FOOD SCIENCE, VOL. 2, J.J. Powers

VEROCYTOTOXIGENIC E. coli, G. Duffy, P. Garvey and D.A. McDowell OPEN DATING OF FOODS, T.P. Labuza and L.M. Szybist NITRITE CURING OF MEAT: N-NITROSAMINE PROBLEM, R.B. Pegg and F. Shahidi DICTIONARY OF FLAVORS, D.A. DeRovira FOOD SAFETY: THE IMPLICATIONS OF CHANGE, J.J. Sheridan et al. FOOD FOR HEALTH IN THE PACIFIC RIM, J.R. Whitaker et al. DAIRY FOODS SAFETY: 1995-1996, A COMPENDIUM, E.H. Marth OLIVE OIL, SECOND EDITION, A.K. Kiritsakis MULTIVARIATE DATA ANALYSIS, G.B. Dijksterhuis NUTRACEUTICALS: DESIGNER FOODS 111. P.A. Lachance DESCRIPTIVE SENSORY ANALYSIS IN PRACTICE, M.C. Gacula, Jr. APPETITE FOR LIFE: AN AUTOBIOGRAPHY, S.A. Goldblith HACCP: MICROBIOLOGICAL SAFETY OF MEAT, J.J. Sheridan et al. OF MICROBES AND MOLECULES: FOOD TECHNOLOGY AT M.I.T., S.A. Goldblith MEAT PRESERVATION. R.G. Cassens PIONEERS IN FOOD SCIENCE, VOL. 1. S.A. Goldblith FOOD CONCEPTS AND PRODUCTS: JUST-IN-TIME DEVELOPMENT, H.R. Moskowitz MICROWAVE FOODS: NEW PRODUCT DEVELOPMENT, R.V. Decareau DESIGN AND ANALYSIS OF SENSORY OPTIMIZATION, M.C. Gacula, Jr. NUTRIENT ADDITIONS TO FOOD, J.C. Bauernfeind and P.A. Lachance NITRITE-CURED MEAT, R.G. Cassens CONTROLLEDlMODIFIED ATMOSPHERENACUUM PACKAGING, A.L. Brody NUTRITIONAL STATUS ASSESSMENT OF THE INDIVIDUAL, G.E. Livingston QUALITY ASSURANCE OF FOODS, J.E. Stauffer SCIENCE OF MEAT & MEAT PRODUCTS, 3RD ED., J.F. Price and B.S. Schweigen NEW DIRECTIONS FOR PRODUCT TESTING OF FOODS, H.R. Moskowitz PRODUCT DEVELOPMENT & DIETARY GUIDELINES, G.E. Livingston, et al. SHELF-LIFE DATING OF FOODS, T.P. Labuza

Journals JOURNAL OF FOOD LIPIDS, F. Shahidi JOURNAL OF RAPID METHODS AND AUTOMATION IN MICROBIOLOGY,

D.Y.C. Fung, M.C. Goldschmidt and D.H. Kang JOURNAL OF MUSCLE FOODS, M.S. Brewer JOURNAL OF SENSORY STUDIES, M.C. Gacula, Jr. FOODSERVICE RESEARCH INTERNATIONAL, P.L. Bordi JOURNAL OF FOOD BIOCHEMISTRY, N.F. Haard and B.K. Simpson JOURNAL OF FOOD PROCESS ENGINEERING, D.R. Heldman and R.P. Singh JOURNAL OF FOOD PROCESSING AND PRESERVATION, B.G. Swanson JOURNAL OF FOOD QUALITY, J.J. Powers JOURNAL OF FOOD SAFETY, T.J. Montville and K.R. Matthews JOURNAL OF TEXTURE STUDIES, M.C. Bourne, T. van Vliet and V.N.M. Rao

FOOD, NUTRACEUTICALS AND NUTRITION, P.A. Lachance and M.C. Fisher

DRY-CURED MEAT PRODUCTS, F. ToldriI

Newsletter

VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE AND


Howard R. Moskowitz, Ph.D.

Moskowitz Jacobs Inc. White Plains, New York

Alejandra M. Mufioz, M.S.

IRIS: International Resources for Insights and Solutions, LLC

Mountainside, New Jersey

Maximo C. Gacula, Jr., Ph.D.

Department of Psychology Arizona State University

Tempe, Arizona

FOOD & NUTRITION PRESS, INC. TRUMBULL, CONNECTICUT 06611 USA

Copyright @ 2003 by

FOOD & NUTRITION PRESS, INC. 4527 Main Street

Trumbull, Connecticut 0441 1 USA

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means: electronic, electrostatic, magnetic tape, mechanical, photocopying, recording or otherwise, without permission in writing from the publisher.

Library of Congress Control Number: 20031 09437

ISBN: 0-91 7678-57-5

Printed in the United States of America

DEDICATIONS

To my mother, Leah Moskowitz. You have encouraged me over the years to develop my ideas, to write them down, and to share with others through publishing. To your constant support and guidance, I owe so much. Thank you.

HOWARD R. MOSKOWITZ

To my son Ryan. Your being, smiles and love are my encouragement, inspiration and drive as a mother and a professional. My experiences and accomplishments are enriched by your presence and love.

ALEJANDRA M. MUROZ

To my parents, Maxim0 Sr. and Elena Calo. Thank you so much for planting in me the value of education, courage, respect, and love while growing up, which became the foundation of my daily life.

MAXIM0 C. GACULA, JR.

PREFACE

We, the authors, thank you for spending some time with us by reading this book. You may have noticed from the title that the book is not a simple presentation of a field with a unified focus. Rather, we deal with controversies. Our field of sensory science has grown mightily in the past decades. To a great extent the growth has come from the resolution of different points of view regarding what is appropriate in sensory science, what are reasonable truths, and what are good practices hallowed by the experience of practitioners. In no case do we present points of view as ultimate truths. As the construction of the book reveals, we rather present different approaches to the same problem, and even different ways to look at the same type of data. In our discussions amongst ourselves and in our evidencing disagreements with each other, we sincerely hope that we provoke you to think more deeply about the issues involved in product assessment, the design of studies, and the analyses of data. If we cause you to think more critically about the problems and even take issue with our points of view (joint and several), we will have succeeded in our task.

HOWARD R. MOSKOWITZ ALEJANDRA M. MUROZ

MAXIM0 C. GACULA, JR.

n

t

I

ACKNOWLEDGMENTS

It is an honor having the following individuals participating in this endeavor.

ANDRE ARBOGAST Biosystkmes 9, rue des Mardors F-21560 Couternon France Email: aarbogast@biosystemes. com

DANIEL ENNIS, Ph.D. The Institute for Perception 7629 Hull Street Road, Suite 200 Richmond, VA 23235 USA Email: ennis@i€press.com

CHRIS FINDLAY, Ph. D. Compusense Inc. 111 Farquhar Street Guelph, Ontario Canada NlH 3N4 Email: [email protected]

PAUL LICHTMAN Sensory Computer Systems 16 South Street Morristown, NJ 07960 USA Email: PaulLichtman@SensorySIMS .corn

CONTENTS

CHAPTER PAGE

1 . The Role of Sensory Science in the Coming Decade . . . . . . . . . . . 2 . International Sensory Science . . . . . . . . . . . . . . . . . . . . . . . . 31 3 . Sensory Mythology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 5 . Validity and Reliability in Sensory Science . . . . . . . . . . . . . . . 97

Methods Versus Real Knowledge . . . . . . . . . . . . . . . . . . . 7 . Descriptive Panels/Experts Versus Consumers . . . . . . . . . . . . 109 8 . Sample Issues in Consumer Testing . . . . . . . . . . . . . . . . . . . 125

Consumer Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Asking Consumers to Rate Product Attributes . . . . . . . . . . . . . 173

11 . Questionnaire Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 Choice of Population in Consumer Studies . . . . . . . . . . . . . . . 209

13 . Biases Due to Changing Market Conditions . . . . . . . . . . . . . . 231 14 . Sample Size N. or Number of Respondents . . . . . . . . . . . . . . 241

1

4 . Contrasting R&D. Sensory Science. and Marketing Research

6 . The Interface Between Psychophysics and Sensory Science: 103

9 .

10 .

12 .

Hedonics. Just-About-Right. Purchase and Other Scales in

15 . The Use and Caveats of Qualitative Research in the Decision-

16 . The Four D’s of Sensory Science: Difference. Discrimination.

17 . 18 . Language Development in Descriptive Analysis and the Formation

Making Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

Dissimilarity. Distance . . . . . . . . . . . . . . . . . . . . . . . . . 267 Replication in Sensory and Consumer Testing . . . . . . . . . . . . .

of Sensory Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 19 . Use of References in Descriptive Analysis . . . . . . . . . . . . . . . 337 20 . Training Time in Descriptive Analysis . . . . . . . . . . . . . . . . . 351 21 . Consumer-Descriptive Data Relationships in Sensory Science . . . 359 22 . Product and Panelist Variability in Sensory Testing . . . . . . . . . 375 23 . Foundations of Sensory Science by Daniel M . Ennis . . . . . . . . 391

by Maximo C . Gacula. Jr . . . . . . . . . . . . . . . . . . . . . . . . 433

Science by Andrd Arbogast. Chris Findlay and Paul Lichtman . 459 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471

299

24 . Applications of SAS@ Programming Language in Sensory Science

25 . Advances and the Future of Data Collection Systems in Sensory

1

I

CHAPTER 1

THE ROLE OF SENSORY SCIENCE INTHECOMINGDECADE

HOWARD R. MOSKOWITZ

Sensory Science is enjoying a period of strong growth, both at the intellectual and at the practical levels. At the intellectual level the influx of statisticians, psychologists, in addition to the usual complement of food scientists, continues to increase the knowledge base and skill set. At the practical level Sensory Science has graduated to first class membership from its former role of a second-class citizen in both academia and corporations. Product developers and product marketers seek out sensory scientists for advice in designing studies, for assistance in collecting data from experts and consumers, and for guidance in interpreting results. Yet, for many years Sensory Science lacked solid intellectual foundations in many of its aspects, perhaps because Sensory Science grew organically, in an undisciplined fashion. The growth was dictated by the early use of Sensory Science as a practical, albeit “kitchen tool, and only later by the concerted efforts of researchers in science and business that would then establish the field on a more rigorous foundation.

The beginnings of Sensory Science involved practitioners, and only later would involve scientists. This history flies counter to the usual order of events, whereby a field begins with science and evolves to practice. As a consequence, sensory scientists are only beginning to have available to them a coherent corpus of knowledge, embodied in textbooks and refereed journals, respectively. The first major text in the field (Principles of Sensory Evaluation of Food, Amerine et al. 1965) comprised short abstracts and mini-discussions of much of the work known to the researcher 35 years ago. The book reflects the bias and approach of Rose Marie Pangborn, one of the first in the field, and certainly the most prominent for the three decades during which she published and flourished. However, the literature in this seminal book was abstracted from contributions in many diverse fields, since Sensory Science itself had not been established. The current state of affairs is far different. Beginning in the early 1980s, authors in the field have contributed numerous volumes, both authored and edited. These volumes provide the reader with overviews as to how the senses work, how to describe product, how to measure sensory and hedonic responses, and how to combine sensory data with analytic data. Journals in the field include Journal of Sensory Studies (published by Food & Nutrition Press, Inc.), and Food Quality and Preference (published by Elsevier Ltd.), respectively. These journals were introduced in the late 1980s and middle 1990s, and reflect the demand for a

1

2 VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE

scientific corpus of knowledge beyond books and published proceedings of symposia.

With the growth of any field there emerge currents and counter-currents that inevitably affect the way the field mamres, and the form that it takes. Sensory Science is no exception. We see today a variety of different trends that we believe will interact to shape the field. Some of them and their likely effects follow. These observations, written in the early years of the decade (2000-2010) may represent just a local perturbation, or may in fact represent a simple extension of trends that began two and three decades ago. One can only understand the full ramifications of a trend looking backward, and not peering forward.

Trend 1 - More Education, More Universities as Centers of Excellence, Better Education

Sensory scientists are becoming more educated in basic science and in the applications of sensory methods. The education obtained by the sensory scientist may be formal (from universities, with defined curricula) as well as practical (from research projects, undertaken in companies or at universities). More education means that the sensory scientist in the future will have a better understanding of where the field has been, what types of problems previous researchers and practitioners have faced, what is held to be true, and what methods have been accepted as standard. Some management consultants would call this an expansion of the "skill" set of the sensory researcher. Armed with this knowledge the sensory researcher may expect to gamer more respect in the scientific and business fields because Sensory Science itself will be recognized as a formal discipline. One can contrast this happy state of affairs with the situation faced by Pangborn and her professional colleagues some 30 to 40 years ago, when sensory researchers were few and far between, and there were no available courses or texts on Sensory Science. The education of a sensory scientist 40 years ago was crafted after discovering and then reading a literature widely dispersed in different content journals.

It is also worth noting that there are many more universities offering education in Sensory Science, so that no one single viewpoint or world-view dominates. Twenty years ago it was the University of California at Davis, under Pangborn's inspired guidance. The Davis way represented, at that time, the way. the ne plus ultra, the revealed doctrine. Today there are a dozen universities or more offering a full series of courses on Sensory Science. Internationally, many more universities are recognizing the need for Sensory Science, and whereas before they had shrugged off this American phenomenon, now they embrace it and offer specialized majors. One need only attend conferences to recognize the

THE ROLE OF SENSORY SCIENCE IN THE COMING DECADE 3

growth of the universities, and the internationalization of the academic field to recognize this development.

Trend 2 - Advanced Statistics Widely Available

Today’s sensory scientists have access to numerous statistical packages available on personal computers. Some of these are powerful versions of traditional computational tools, such as analysis of variance, factor analysis, discriminant function analysis, and the like. Other statistical tools incorporate developments in mapping, where the objective is to locate the stimulus product or the panelist or the attribute (or even all three) in a geometrical space with the property that points “close together” in the space are similar along one or more characteristics. These tools go under the name of multidimensional scaling. A third set of tools involves the relation of two or more sets of variables. These methods include partial least-squares (PLS), and reverse engineering. A fourth set of tools involves modeling and optimization, with the objective to identify processing or ingredient conditions leading to a high level of customer satisfaction, while simultaneously maintaining the independent variables and specified dependent variables within the range tested. Properly used, these advanced statistics enable the sensory researcher to better understand relations among stimuli or relations among variables. They lead to new insights that make the results more valuable. For example, maps or models provide significant value both to the scientist looking to understand how nature works, and to the developer, looking to create new products that fulfill the consumer requirements.

Trend 3 - Increased Contact among Researchers Through Books, Journals and Specialized Conferences

If we look back forty years ago, to 1960 or thereabouts, we find virtually no consistent recognition of Sensory Science as an emerging specialty. The articles on Sensory Science were scattered across different journals, often as “reviews” of “how to do things,” rather than as structured reports. There were no journals in the field devoted to Sensory Science per se. There might be featured articles from time to time about the importance of understanding the senses for a particular product category. However, there was no single source to which an interested person could turn to learn what was really known about the senses with regard to product development and consumer perception of products. Furthermore, there were no conferences dealing specifically with the sensory aspects of products. Conferences would feature one or another speaker talking about Sensory Science, but often such a speaker was relegated to a minor position on the program.

Changes came in the 1960s. As noted above, the Amerine, Pangborn and Roessler book, which was the first to appear with extensive scientific literature


and approaches, was published in the middle of the decade. Indeed, it was only in the middle 1960s and afterward that any attention was paid to the chemical senses (taste, smell) and the ancillary use of these senses in Sensory Science. Among the first organized meetings was the Gordon Research Conference at Issaquah, Washington, devoted to the chemical, and an early meeting at the Swedish Institute for Food Preservation Research at Gothenberg, Sweden. These meetings promoted interaction among the sensory researchers who were just beginning to recognize that they were founding a distinct science. This author remembers the palpable excitement generated by the early meetings, where perhaps for the first time researchers in a variety of disciplines began to recognize that they were forming the nucleus of a new science. Researchers such as Emily Wick, of Arthur D. Little and then of MIT (Food Science) would later talk fondly about these early meetings and the agenda of research goals that they set.

The trend today is for far more contact among researchers. The United States led the way in the 1970s by founding the Sensory Evaluation Division of the Institute of Food Technologists (IFT), and the Sensory Evaluation Division (E-18) of the American Society for Testing and Materials. The 1990s witnessed an explosive growth in societies, meetings, journals, and all forms of contacts among researchers. Annual meetings of the Sensory Evaluation of the IFT, long the mainstay of the sensory world, were complemented by professional meetings of Committee E-18 on Sensory Evaluation of the ASTM (American Society for Testing and Materials). Worldwide sensory scientists contact each other more frequently through meetings such as the triennial and now biennial Pangborn Symposium, the biennial Sensometrics meetings, and other organizations. Sensory scientists are also beginning to attend meetings such as Food Choice, and participate heavily in specialized conferences dedicated to one or another theme involving food.

Trend 4 - Beyond Expert Panels Towards Consumer Research

Many sensory researchers now recognize that their specialization in product testing fits well with the emerging corporate needs in consumer research. They have changed their focus from experts to consumers. Twenty-five years ago it was rare for a sensory scientist to venture out into consumer or market research. Sensory scientists assumed a purist stance, demanding highly controlled test environments (the well-known “booths”), well-practiced panels, experts if possible, and analytical rigor (both in statistical terms and in conceptual terms). Consequently, sensory scientists ran their own in-house expert panels, and market researchers ran consumer studies, often on the same products. Sensory scientists asked relatively few questions of consumers, if they ever tested consumers, whereas market researchers asked much of consumers. The two


professions, Sensory Science and market research, never really met, or if they did then the encounter was simply one of the many chance encounters that inevitably occur at large meetings, perhaps in connection with a specific project. Both sensory scientists and consumer researchers attempted to gain corporate recognition for product guidance. Consumer researchers by and large were untrained in sensory methods, and more accustomed to what we might today consider primitive test procedures. There was the inevitable fight for “turf,” and for corporate recognition and resources. Often the fight took the guise of a polite interaction and disagreement. Just as often the fight took the guise of an all out confrontation for control, survival, and corporate respect.

Today in many but not all corporations there is much more communication between sensory scientists and consumer researchers. Indeed, in some forward- looking companies, sensory scientists and market researchers report to the same vice president, eliminating what traditionally has been an area of contention. As a consequence of the enhanced communication between the two disciplined groups responsible for guidance, many companies now enjoy the fruits of their knowledge. For example, advanced methods for product development, such as response-surface mefhods, once an arcane statistical discipline, are now widely used in many companies to identify the effects of ingredients on sensory and liking reactions, and to optimize foods along a limited number of formula dimensions. Consumer research procedures, such as category appraisal to assess a wide range of competitive products in regard to Drivers of Liking@ have been adopted by sensory scientists for routine use. Sensory scientists have even gotten into the concept development business, along with consumer researchers. Rather than handing over to marketing the role of creating product concepts, R&D directors have accepted the challenge of membership in a team that creates concepts, joining forces with the marketing group. The interaction of sensory scientists and consumer researchers is not always a pleasant one because of the aforementioned turf issues, and because the relations between the two disciplines grew out of a history of competition, not cooperation.

Hazards and Remedies. With every advance, however, there are always hazards to overcome. One of these hazards is the tendency of sensory scientists to think of themselves as the low cost suppliers of data, a self-view reinforced by many short-term focused corporate managers. In the face of increasing costs to obtain consumer data, many sensory scientists still maintain that they can produce data at lower costs than that of conventional market researchers. Market researchers are also held to limited budgets, but over the years they have had the benefit of budgets that they can allocate to outside suppliers and consultants. Inevitably, market researchers become smarter as they interact with outsiders who bring to the problem a different point of view. In contrast, the sensory scientist may miss this opportunity to grow through outward focus. Sensory


scientists make the mistake of trying to do more maintenance work and less innovative development work. It is, in fact impossible for sensory scientists to mature, do more innovative work, when the majority of the budget and the corporate kudos come from the performance of maintenance work at ever-lower costs. Simply stated, the wrong behavior is being reinforced, and the sensory researcher is turned into a drone, ever so slowly, but ever so relentlessly.

The Sensory Scientist as a Sensory Professional

Forty years ago there were no sensory professionals. A sensory professional at best was someone conversant with the methods of testing, with experience, capable of carrying out fairly straightforward tests. The concept of a “sensory professional” in and of itself would not have been thinkable. There was no corpus of knowledge that this “professional” would access, other than the disparate articles in the different subject fields referred to above.

In the middle 1970s, with the acceptance of Sensory Science by companies, but without the widespread knowledge base, sensory scientists needed to define themselves. For want of a better name they called themselves sensory professionals. They could not call themselves sensory researchers, for that was a label more appropriate to biologists and experimental psychologists. In the middle 1970s, therefore, the title of sensory professional served to legitimize the developing field and the workers therein. Looking back one can see how the use of the term “sensory professional” did indeed produce a greater espirit de corps, and more self-pride. As one might imagine, however, the use of the term “sensory professional” also hindered development and growth, simply because it gave the researcher a title that signified “arrival,” rather than “skill set.”

The situation has dramatically changed during the past 25 years. The change has been continual, not discrete, with few individual points that signal a change. There is a corpus of knowledge, there are standard methods, and the sensory scientist continues to grow. The meaning of sensory professional is now changing, taking on more “baggage, ” both positive and negative. The sensory professional has won some academic recognition, attends and presents at conferences, occasionally publishes, and interacts with other scientists in various subject fields. At the same time, the use of the term “sensory professional” appears to be diminishing as practitioners enter from other professions, e.g., psychology, food science, and sociology, equipped already with well accepted academic and professional credentials. The term “sensory professional” is now often used for the technician rather than the higher-level management end of the field, perhaps as a legitimizing device for those individuals. Happily, however, the upper strata of sensory scientists do not need the title of “sensory professional” in order to gain legitimacy.

THE ROLE OF SENSORY SCIENCE IN THE COMING DECADE I

Can We Improve Sensory Education?

Sensory education has come a long way in the past forty years. The early days of sensory education consisted primarily of statistical analysis techniques, and detailed descriptions of how to run studies. Both of these went together, because the food world perceived Sensory Science as “taste testing.” Indeed, the informal appellation of Sensory Science was “taste testing. ” Participants would be invited down for a “taste test” in the “taste-test kitchen.” In the main a sensory scientist would use inferential statistics (e.g., tests of difference to determine whether two or more products were different from each other, whether or not storage had an effect on sensory quality, and the like). Rarely did the sensory scientist venture beyond comparison among products to higher levels such as modeling. Indeed, the notion of modeling was antithetical to taste testing, except perhaps to model the effects of time of storage on product acceptance, and even in that case the demand for modeling came from the food scientist, not from the “taste tester.” With this type of history it is no wonder that for many years sensory researchers had little in the way of a formal, rich, education that would prepare them to advance the field. Execution, not education, was called for. Those who succeeded did the test properly, not the proper test.

What about the future of sensory education? Today’s texts on Sensory Science amalgamate with various degree of success such different disciplines as sensory psychophysics and sensory biology, cognitive psychology, statistical analysis, and discussions of the numerous findings published in the literature on a variety of problems of interest to the sensory scientist. Some of these topics are intensity scaling, mixtures, time-intensity , expert panels, correlation of sensory and instrumental measures, etc. Sensory education appears to be developing appropriately, on schedule, with increasing scope and sophistication. The trends for the next generation of sensory education will probably encompass more cognitive psychology (e.g., concept development of food concepts; applied concept development), as well as higher level statistical techniques to discover patterns and relations in existing data (e.g., multidimensional scaling, partial least-squares, neural nets, etc.). Today’s professors of Sensory Science favor advanced thinking, along with more integration of information and modern techniques from other fields. Today’s sensory professors are well aware, as never before, of the profound inter-connectivity of different fields of research underlying Sensory Science. It should come as no surprise that the education is more rigorous, more thought provoking, and more wide-ranging than ever before. We may expect to see that happy trend continue, and the field mature even more.

It is worthwhile noting that the issue of proficiency and accreditation is surfacing both in Sensory Science (see MuAoz, following), and in related areas,


such as marketing research (William Neal, personal communication to HRM, 1999). As the disciplines of study design, data acquisition, and analysis become more accepted in industry, and as the financial stakes rise and competition sets in, many individuals in market research “hang out their shingle,” and evolve rapidly into practitioners. These superficially trained individuals without depth experience in Sensory Science, like those individuals lacking any experience in Sensory Science, may ultimately harm the profession. It remains to be seen whether accreditation can be awarded on an equitable basis, without favoritism and nepotism. Yet, with the increasing financial importance of product successes, and with the intense competition among practitioners, it is vital that some form of validation of the researcher be instituted.

Fads and Beliefs Versus Enduring Truths

As Sensory Science matures into an accepted discipline we also see emerging a variety of fads, or to be less critical and more generous, a variety of different popular topics. Fads in Sensory Science comprise approaches to problems that endure for some time, but eventually fade away, either because they are founded on “me-too-ism,” or because they are well-funded by corporations that want to keep abreast of the most au courant methods. Each era of research brings its own fads, partly because of the cross-pollination of disciplines, partly because researchers want to do new work, and not simply shamble along well-trodden paths. Nothing so gratifies one as participating in research deemed to be “new and ground-breaking” by the so-called cognoscenti, or at least by those currently in power, in favor, or in positions of professional authority.

Here are five fads that have enjoyed favor over the past years:

(1) Scales: e.g., scaling procedures (different types of rating scales) and representation methods (e.g., different types of mapping). One has to be careful not to confuse fads with the honest attempt to bring methods/ procedures from other subject fields into Sensory Science. What is one person’s science may be another person’s fad. Only time will tell whether scaling procedures are faddish or substantive, and contributory.

(2) Panelist Selection: e.g., specific screening procedures to identify “sensitive panelists.” Extensive panelist screening may be a fad because all too often the sensitivity in the panelist screening has nothing to do with the product being evaluated, but is just adopted because someone in the corporation, or someone in the literature recommended doing so.


(3) Replication: The reason for the replicates is not clearly stated, nor often even understood. Replication is faddish when the rationale is not provided, but simply followed blindly. On the other hand, replication is not faddish when it is used to estimate subject variability from evaluation to evaluation.

(4) Product Test Limits: Limiting the number of products tested by a panelist to very few because one assumes that the panelist cannot accurately evaluate more than a few products without becoming confused. This assumption of panelist’s lack of ability is belied by the observation that in every day life panelists have no discrimination problems when eating. They rarely if ever report loss of sensitivity during a meal, and in fact hardly pay attention to the fact that they are consuming mouthful after mouthful of product, without seeming to lose any sensitivity at all.

(5 ) Expert Panelists as The Repository of Subjective Truth: The researcher uses expert panelists to describe the sensory magnitude of a stimulus, under the assumption that the consumer is absolutely incapable of validly scaling sensory magnitude of a stimulus on a variety of different sensory dimensions. This belief is a passing fad, belied by the literature, and simply spread through “me-too-ism” (viz., “ I too have an expert panel to acquire valid sensory data”). The consumer, in turn, is relegated to ratings of liking. This is a particularly pernicious fad that, in this author’s opinion, has retarded progress in the field, and has been often motivated by less than noble reasons.

Enduring truths, in contrast, are usually of a much more prosaic nature, and seem almost trivial. Enduring truths may be the obvious:

(1) You Can’t Describe What You Can’t Verbalize. For example, if the researcher wants to use novel terms for descriptive analysis, then the researcher should orient or train the panelist on these terms, or at least define them. Orientation does not necessarily mean weeks of intensive training. Orientation may simply entail a clear, usable explanation.

(2) Too Few Scale Points Hinder Discrimination. Another enduring truth is that by confining the panelist to a short scale (e.g., three scale points), the researcher loses a great deal of information about the differences among products.

(3) People Perform Pretty Well. They are biologically adapted to do so. A third enduring truth is that panelists can accurately track the changes in physical characteristics of the product, especially if they understand the


meaning of the scale and the meaning of the attribute. Psychophysicists (Stevens 1975) and sensory scientists alike (Moskowitz 1983) have demonstrated this capability again and again, in numerous, well-controlled studies. It is unfortunate that many uneducated practitioners aver, quite vehemently, that panelists cannot do much. In contrast, the human being is a marvelously constructed organism that has no problem performing most evaluation tasks.

REFERENCES

AMERINE, M.A., PANGBORN, R.M. and ROESSLER, E. 1965. Principles of Sensory Evaluation of Food, Academic Press, San Diego.

MOSKOWITZ, H.R. 1983. Product Testing and Sensory Evaluation of Food: Marketing and R&D Approaches. Food and Nutrition Press, Trumbull, Conn.

STEVENS, S.S. 1975. Psychophysics, An Introduction To Its Sensory, Neural And Social Prospects, John Wiley & Sons, New York.

ALEJANDRA M. -0Z

Sensory Science has evolved from supporting “expert taste tastings” in the beer, wine and other similar industries (Hinreiner 1956; Amerine et al. 1959) to developing formal and sound methods, to incorporating elements of other disciplines, such as psychology, statistics and psychophysics in its methods and developments, and established itself as a respected science. In the last five decades, Sensory Science has been refined, has matured and been applied in other disciplines, and its professionals have learned and applied the existing methods in many industrial, academic and research applications (Pangborn 1964). In addition, sensory professionals have participated in and supported activities that have contributed to their continued education and growth including workshops, symposia and publications.

Entering the new millennium we professionals in this field are awaiting and willing to support and contribute to our “next steps” and new developments. Sensory Science will continue to grow. How can we grow as individuals, and make our field grow in the next decade and new millennium? It will continue on the path of establishing itself as a well-known, well-accepted applied discipline and will expand into new areas never before pursued. Some of the areas Sensory Science will concentrate on in the next decade include the following, as viewed by this author.


Continued Application of Existing Sound Sensory/Consumer Methods

Experienced sensory professionals have used the sound sensory and consumer testing methods in a wide range of applications, modified and adapted them to new situations/applications, and confirmed their value through many successes over the years. As discussed below, we need to develop and apply new sensory techniques to contribute to the growth of our field. However, while we develop, test and validate new methods, we will continue using these well- known, established and validated methods to accomplish our daily functions in industry, research and academia. In addition, we will teach these methods to our young professionals to provide them with a good foundation to operate in the field. These methods that have solid principles and that will continue being used by sensory professionals include standard discrimination tests (simple difference, triangle, duo trio tests, etc.) (Stone and Side1 1993; Meilgaard et al. 1999), consumer qualitative and quantitative consumer tests to collect consumer opinions, acceptance and/or preference responses as well as intensity/diagnostics product information (Peryam and Pilgrim 1957; Moskowitz 1983; Chambers and Smith 1991; Stepherd et al. 1991; Casey and Krueger 1994; Krueger 1994; Resurreccion 1998), as well as the fundamental descriptive methods, such as the Flavor and Texture Profile and the Quantitative Descriptive Analysis Methods (QDA), (Caul 1957; Brandt et al. 1963; Stone et al. 1974; ASTM 1992), and its derivatives, such as Modified Profile Methods (Muiioz and Civille 1992; Stampanoni 1994; Muiioz and Bleibaum 2001).

In addition, to better understand and apply existing methods, sensory professionals should continue to learn from and to review the wealth of published information on sensory and consumer studies and their applications, which is published in journals such as the Journal of Sensory Studies, Food Quality and Preference, Chemical Senses, Journal of Texture Studies, etc. Hopefully, an effort can be made by the sensory professionals to set aside the time in order to keep up-to-date with this published information.

As scientists, we should also encourage, support and commend the use of and the research on new methods and techniques, while continuing to apply existing methods. As these new methods and approaches appear in the scientific literature, we should expend the effort to learn these new developments, as well as have the courage to apply them.

The Development and/or Use of New Methods and Concepts

As with any other science, Sensory Science is evolving and growing. New theories, methods and concepts are being developed and applied. Sensory professionals are encouraged to contribute to these developments and apply several of the new techniques.


Challenging areas and new developments that have been addressed in the past few years that sensory professionals need to track, learn and apply include:

non traditional and new discrimination test theories and methods, especially those based on signal detection theory, Thurstonian scaling, R-index (O’Mahony 1979; Ennis 1993, 1998; Ennis and Bi 1998; Cliff ef al. 2000; Rousseau 2001; Rousseau and O’Mahony 2001).

deeper consumer understanding and exploration of consumer articulated and unarticulated wants and needs, using new consumer testing approaches, such as, ethnography, projective and elicitation techniques (Swan ef al. 1996; Bech er al. 1997; Perry 1998; Baxter ef al. 1998; Rousset and Martin 2001; Muiioz and Everitt 2003; Urbick 2003; Woodland 2003).

application of traditional and creative qualitative techniques (Krueger 1994; Dudek and Childrens 1999).

new statistical applications and advanced analysis for sensory data and applications including analysis of categorical and replicated data, application of experimental design, new statistical approaches for data relationships, etc. (Pouplard er al. 1997; Wilkinson and Yuksel 1997; Brockhoff and Schlich 1998; Kunert 1998; Bi er al. 2000; Tang er al. 2000; Malundo er al. 2001; Best and Rayner 2001).

data relationships techniques (consumer, descriptive, instrumental) to integrate product information and to understand products and populations (e.g., consumers) (McEwan 1996; ASTM 1997; Wilkinson and Yuksel 1997; Elmore ef al. 1999; Malundo ef al. 2001).

monitoring techniques needed to calibrate attribute/descriptive panels (sensory and statistical methods) (Schlich 1994; McEwan 1999; Qannari and Meyners 2001; King er al. 2001).

Participation in, and Support of All Research Involving the Development of New Concepts and Methods

Currently, most of the publicly available sensory research is conducted by universities. Sensory professionals working in industry are either too busy to participate in research studies, or are not allowed to publish, since this information sharing may not be supported by management. Our field can only grow to the extent that research and new developments are completed. Therefore, it is our obligation to encourage and participate in this activity. In


this upcoming decade we should participate in and/or support much of the research in our field.

Financial support is critical. Sensory programs in universities benefit from the support received by grants, industry and other organizations to be able to get involved in sensory research. Hopefully more support will be given to aid universities in completing more and better research. Even if some sensory professionals are unable to personally engage in research, they can still be part of the growth by reading and learning about the new developments and applying them. A number of sources of support have recently become available, giving practitioners and academics alike the prospect of even greater developments in the field. Recently the ASTM committee El8 on Sensory Evaluation has initiated discussions on the need to support additional research in the field of Sensory Science and thus formed a standing committee on sensory research. Its goal will be to select relevant topics needing research, obtaining funds and manage the research efforts within and outside its membership.

Delineation of Sensory Science’s Name and Role

When Sensory Science established itself as a science, it was named Sensory Evaluation and encompassed analytical/discriminative and consumer methods (Amerine et al. 1959; Pangborn 1964). In the past few years, two trends have been observed: (1) Many professionals refer to our field as Sensory Science vs. Sensory Analysis or Evaluation; and (2) Many companies and professionals limit the role of Sensory Science to analytical/discriminative testing, thus exclude consumer testing. In addition, many of these companies make a distinction between the roles and professional involvement of sensory and consumer scientists.

We sensory professionals should be aware that there are three different names used interchangeably for our field: Sensory Science, Sensory Analysis and Sensory Evaluation. Currently, there is a trend toward preferring the use of the name Sensory Science to connote the nature of this discipline. However, we should be cognizant of the fact that many companies and individuals differentiate between Sensory Science and Consumer Science. Thus, nowadays the role of a Sensory Science group within an organization cannot be easily inferred. An explanation of the tasks and involvement of a sensory group is needed to understand its role.

In this author’s opinion the differentiation should not exist. A sensory professional should be recognized as one who is knowledgeable and uses BOTH sensory and consumer methods to provide answers and guidance. It is our responsibility to clarify the role of Sensory Science and ensure that individuals and companies understand the basis and role of this discipline. Until this


happens, it is important to recognize that this differentiation will continue to exist.

In this publication, this author will use the word sensory professional or scientist to describe the individual who is knowledgeable and uses BOTH sensory and consumer methods to fulfill his job responsibilities. Occasionally, if necessary, the term sensory/consumer scientist may be used.

Global Sensory Science

Sensory Science like other sciences has taken a global view (Stone and Side1 1995). This global perspective is needed, due to: (1) the extensive collaboration taking place among professionals around the world; and (2) the need to develop and apply product evaluation techniques globally in order to respond to the industry’s needs to test products abroad.

Therefore, in this author’s view the globalization of Sensory Science is happening and will continue to expand in the next decade in five areas: (1) the execution of cross cultural studies, as the companies we work for expand their business and interests into other countries and cultures; (2) trans-national collaboration for the development or improvement of companies’ affiliate/foreign sensory programs; (3) the need for companies to harmonize approaches, methods and references across all their affiliates worldwide; (4) the recognition of a common goal to understand global consumer responses and the need to adapt sensory consumer methods for world-wide use, recognizing different cultures; and (5 ) the interaction, exchange of ideas and collaboration among sensory scientists around the world.

An in-depth discussion of this important topic is presented in Chap. 2.

Sensory Proficiency and Accreditation

Proficiency/accreditation is a very current, pressing issue being addressed by sensory professionals worldwide. The general goal of all proficiency and accreditation programs is to establish guidelines for the certification of sensory laboratories and professionals. Proficiency testing was recently initiated and sensory professionals all over the world are eager to learn about the progress and participate in this effort.

Proficiency testing is the use of interlaboratory test comparisons to determine the performance of individual laboratories for specific tests, and is used to monitor the consistency and comparability of a laboratory’s test data with other similar laboratories. Participation in proficiency testing schemes provide laboratories with an objective means of assessing and demonstrating the reliability of their data, and to assess the ability of the laboratory to competently perform tests. Proficiency testing schemes are used by laboratory accreditation bodies as part of the process to assess the ability of laboratories to competently


perform tests for which accreditation is held. Proficiency testing schemes are well established in certain scientific disciplines. However, proficiency testing schemes that allow laboratories to assess their performance and competence in Sensory Science were not available.

The first attempt to address sensory proficiency was initiated in 1999 by PROFISENS, a EU project financed by the European Commission Standards Measurements and Testing SMT. The PROFISENS project was internationally based and included leading laboratories in Sensory Science throughout Europe in the project consortium. Also represented were multinational industries with particular interests in ensuring that the guidelines developed met the needs of industry. Furthermore, the guidelines were evaluated by several external specialists from the USA and Canada, and their comments were incorporated into the final proficiency scheme guidelines that were published.

The main output of the PROFISENS project was the publication of a guideline document for conducting proficiency testing in Sensory Science. Published as Guideline No. 35 by Campden & Chorleywood Food Research Association, UK (CCFRA) (the coordinator), the document covers the technical requirements for conducting sensory proficiency tests and the management systems requirements of the proficiency scheme provider (Lyon 2001). Therefore, the document provides an overall summary of how a scheme would operate and the relative responsibilities of individuals or organizations in the planning and conduct of sensory proficiency tests.

Other relevant publications of this project are the papers by McEwan er al. (2002a, b) that describe measuring performance panel issues for ranking and profile testing. While the PROFISENS project has come to an end, it has provided the basis for future work in this area.

In response to this effort the ASTM El8 committee has formed a task group to address this issue through ASTM International (Chambers 2003). It is anticipated that other countries will respond to this challenging issue as well.

Sensory Science and the Internet

In the new millennium all scientific work, business enterprises, and personal endeavors and undertakings will continue revolving around the Internet. It is anticipated that sensory professionals will use the Internet for information gathering and communication purposes, but also to conduct tests.

The web helps researchers interact with consumers and panelists in ways barely imaginable over the past decade. Netmeetings continue to give rise to new advances in synchronous interactions with our subjects coordinated and facilitated by intelligent machines. This gives rise to synchronous meetings that allow panels, focus groups, and product evaluators to share their discussions


over both space and time. Advances in privacy will help in the maintaining of the anonymity of respondents and confidentiality of responses (Stucky 2001).

Currently, there are companies that have used the Internet in the area of consumer testing (Kolkebeck 2002) and sensory and descriptive analysis (Curt er al. 2000; Findlay 2002). In the area of consumer testing, consumers are being recruited through the Internet, as well as asked to complete surveys and testing. In the area of descriptive analysis, panels are being trained and asked to evaluate products and completehend their evaluation results through the Internet (Curt et al. 2000).

Kolkebeck (2002) reports the following successful uses of the Internet in consumer testing :

(1) Recruiting Methods

a. Recruiting agencies contact prospective respondents in their database by email and request that they call the agency to complete the screening procedure; and

b. Recruiting agencies send email notification and URL link to a screening questionnaire to potential respondents in their database.

(2) Interviewing Methods

a. Home Use Tests (HUTS): Respondents are either mailed producth or come to a central location to pick up producth. Diariedballots are completed on-line. Central Location Tests (CLTs): Respondents come to testing facilities to participate in a quantitative test to evaluate products that require controlled preparation or to evaluate concepts or prototypes in a secure environment. On-line ballots are completed by the respondent.

c. Multi-Modal Data Collection: Respondents choose to complete questionnaires via telephone or Internet/Web.

b.

Those companies developing these services capitalize on the advantages of the communication via the Internet, allowing:

(1) communication between professionals within the organization; (2) direct, day to day, communication with individual consumers through chats,

web forms, forums, noteboards, internet communities, and email; (3) evaluation of products by consumers or trained panelists from their home

or location, and thus eliminating transportation time and logistics; (4) evaluation of products at different locations (e.g., countries, cities,

laboratories);

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VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE AND … · 2013. 7. 17. · F N P PUBLICATIONS IN FOOD SCIENCE AND NUTRITION Books VIEWPOINTS AND CONTROVERSIES IN SENSORY SCIENCE,