Sensory Evaluation Techniques, Fourth Edition

466 Pages·2006·7.07 MB·English

by  Morten C. Meilgaard

Fourth Edition
Sensory
Evaluation
Techniques
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Sensory
Evaluation
Techniques
Fourth Edition
Morten Meilgaard, D.Sc.
Senior Technical Advisor
The Stroh Brewery Company
Detroit, Michigan
Gail Vance Civille, B.S. B. Thomas Carr, M.S.
President Principal
Sensory Spectrum, Inc. Carr Consulting
New Providence, New Jersey Wilmette, Illinois
Boca Raton London New York
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Library of Congress Cataloging‑in‑Publication Data
Meilgaard, Morten.
Sensory evaluation techniques / Morten C. Meilgaard , Gail Vance Civille, B. Thomas Carr. ‑‑ 4th
ed.
p. cm.
Includes bibliographical references and index.
ISBN‑13: 978‑0‑8493‑3839‑7
ISBN‑10: 0‑8493‑3839‑5
1. Sensory evaluation. I. Civille, Gail Vance. II. Carr, B. Thomas. III. Title.
TA418.5.M45 2006
664’.07‑‑dc22 2006015039
Visit the Taylor & Francis Web site at
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This bookis dedicated to
Manon, Frank, and Cathy
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Preface
Howdoesoneplan,execute,complete,analyze,interpret,andreportsensorytests?Hope-
fully,thepracticesandrecommendationsinthisbookcoverallofthosephasesofsensory
evaluation. Thetext ismeant as apersonalreference volume for foodscientists, research
anddevelopmentscientists,cerealchemists,perfumers,andotherprofessionalsworking
inindustry,academia,orgovernmentwhoneedtoconductgoodsensoryevaluation.The
bookshouldalsosupplyusefulbackgroundtomarketingresearch,advertising,andlegal
professionalswhoneedtounderstandtheresultsofsensoryevaluation.Itcouldalsogive
a sophisticated general readerthe same understanding.
Becausethefirsteditionwasusedasatextbookattheuniversityandprofessionallevels,
partlyincoursestaughtbytheauthors,thesecond,third,andfourtheditionsincorporatea
growingnumberofideasandimprovementsarisingoutofquestionsfromstudents.The
objectiveofthebookisnowtwofold.First,asa“howto”textforprofessionals,itaimsfora
clear and concise presentation of practical solutions, accepted methods, and standard
practices. Second, as a textbook for courses at the academic level, it aims to provide just
enough theoretical background to enable the student to understand which sensory
methods are best suited to particular research problems and situations and how tests
can best beimplemented.
The authors do not intend to devote text and readers’ time to resolving controversial
issues, but a few had to be tackled. The second edition was the first book to provide an
adequate solution to the problem of similarity testing. This was adopted and further
developed by ISO TC34/SC12 on Sensory Evaluation, resulting in the current “unified”
procedure(Chapter6,SectionII,p.60)inwhichtheuser’schoiceofa-andb-risksdefines
whether difference or similarity is tested for. Another first is the unified treatment of all
ranking tests with the Friedmanstatisticin preference to Kramer’s tables.
Chapter 11 on the Spectrume method of descriptive sensory analysis, developed by
Civille, has been expanded. The philosophy behind Spectrum is threefold: (1) the test
should be tailored to suit the objective of the study (and not to suit a prescribed
format); (2) the choice of terminology and reference standards should make use not
onlyofthesensesandimaginationofthepanelists,butalsooftheaccumulatedexperience
ofthesensoryprofessionasrecordedintheliterature;and(3)asetofcalibratedintensity
scales is provided that permits different panels at different times and locations to obtain
comparableandreproducibleprofiles.Thechapternowcontainsfulldescriptivelexicons
suitable for descriptive analysis of a number of products, e.g., cheese, mayonnaise,
spaghetti sauce, white bread,cookies, and toothpaste. Also new is a set of revisedflavor
intensity scales for attributes such as crispness, juiciness, and some common aromatics
and two training exercises.
Theauthorswishthebooktobecohesiveandreadable;wehavetriedtosubstantiateour
directionsandorganizeeachsectionsoastobemeaningful.Wedonotwantthebooktobe
a turgid set of tables, lists, and figures. We hope we have provided structure to the
methods, reason to the procedures, and coherence to the outcomes. Although our aim is
todescribealltestsincurrentuse,wewantthistobeareferencebookthatcanbereadfor
understanding as well as a handbook that can serve to describe all major sensory evalu-
ation practices.
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Theorganizationofthechaptersandsectionsisalsostraightforward.Chapter1liststhe
stepsinvolvedinasensoryevaluationproject,andChapter2brieflyreviewstheworkings
ofoursenses.InChapter3,welistwhatisrequiredoftheequipment,thetasters,andthe
samples; while in Chapter 4, we have collected a list of those psychological pitfalls that
invalidatemanyotherwisegoodstudies.Chapter5discusseshowsensoryresponsescan
bemeasuredinquantitativeterms.InChapter6,wedescribeallthecommonsensorytests
for difference, the Triangle, Duo–trio, etc.; and, in Chapter 7, the various attribute tests,
such as ranking and numerical intensity scaling, are discussed. Thresholds and just-
noticeable differences are briefly discussed in Chapter 8, followed by what we consider
the main chapters: Chapter 9 on selection and training of tasters, Chapters 10 and 11 on
descriptivetesting,andChapter12onaffectivetests(consumertests).Allthedescriptive
references have been reviewed and revised for the Spectrum references in Chapter 11.
Chapter 12 defines, in detail, several qualitative and quantitative classic methods for
testingwithconsumersandincludessubstantialreviewsof“fuzzyfrontend”andinternet
research techniques.
The body of text on statistical procedures is found in Chapters 13 and 14, but, in
addition, each method (Triangle, Duo–trio, etc.) in Chapters 6 and 7 is followed by a
number of examples showing how statistics are used in the interpretation of each. Basic
concepts for tabular and graphical summaries, hypothesis testing, and the design of
sensorypanelsarepresentedinChapter13.Werefrainfromdetaileddiscussionofstatisti-
cal theory, preferring instead to give examples. Chapter 14 discusses multifactor
experiments that can be used, for example, to screen for variables that have large effects
onaproduct,toidentifyvariablesthatinteractwitheachotherinhowtheyaffectproduct
characteristics, or to identify the combination of variables that maximize some desirable
product characteristic such as consumer acceptability. Chapter 14 also contains a discus-
sionofmultivariatetechniquesthatcanbeusedtosummarizelargenumbersofresponses
withfewer,meaningfulonestoidentifyrelationshipsamongresponsesthatmightother-
wise go unnoticed, and to group respondents of samples that exhibit similar patterns of
behavior.NewinthefourtheditionisanoverviewofThurstonianScaling.Inadditionto
studying differences among products, Thurstonian Scaling can be used to uncover the
decisionprocessesusedbyassessorsduringtheirevaluationsofproducts.Alsonewinthe
fourth edition is a detailed discussion of data-relationship techniques used to link data
from diverse sources collected on the same set of samples. The techniques are used to
identify relationships, for example, between instrumental and sensory data or between
sensoryandconsumerdata.Theycanrevealthesensoryandinstrumentalcharacteristics
of products that have the greatest impact on acceptance and the intensities of these
characteristics that arepredicted to bemostwellliked by consumers.
Attheendofthebook,thereaderwillfindguidelinesforthechoiceoftechniquesand
for reporting resultsplus the usual glossaries,indexes, and statistical tables.
With regard to terminology, the terms assessor, judge, panelist, respondent, subject, and
taster are used interchangeably as are he, she, and (s)he for the sensory analyst (the
sensory professional, the panel leader) andforindividual panel members.
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Authors
Morten C. Meilgaard, M.Sc., D.Sc., F.I. Brew, is visiting professor (emeritus) of Sensory
ScienceattheAgriculturalUniversityofDenmark,andheisseniortechnicaladvisorand
vicepresidentofresearch(alsoemeritus)attheStrohBreweryCo.,Detroit,Michigan.He
studied biochemistry and engineering at the Technical University of Denmark where he
returnedin1982toreceiveadoctorateforadissertationonbeerflavorcompoundsandtheir
interactions.After6yearsasachemistattheCarlsbergBreweries,heworkedfrom1957to
1967andagainfrom1989asaworldwideconsultantonbrewingandsensorytesting.He
servedfor6yearsasdirectorofresearchforCervecer´ıaCuauhte´mocinMonterrey,Mexico,
and for 25 years with Stroh. At the Agricultural University of Denmark, his task was to
establishsensoryscienceasanacademicdisciplineforresearchandteaching.
Dr. Meilgaard’s professional interests are the biochemical and physiological basis of
flavor, and more specifically, the flavor compounds of hops and beer and the methods
by which they can be identified, namely, chemical analysis coupled with sensory evalu-
ation techniques. He has published over 70 papers. He is the recipient of the Schwarz
AwardandtheMasterBrewersAssociationAwardofMeritforstudiesofcompoundsthat
affectbeerflavor.HeisthefounderandpastpresidentoftheHopResearchCouncilofthe
U.S.,andheisthepastchairmanoftheScientificAdvisoryCommitteeoftheU.S.Brewers
Association. For 14 years, he was chairman of the Subcommittee on Sensory Analysis of
theAmericanSocietyofBrewingChemists.HehaschairedtheU.S.delegationtotheISO
TC34/SC12 Subcommittee on SensoryEvaluation.
Gail Vance Civille, B.S., is president of Sensory Spectrum, Inc., New Providence,
New Jersey, a management consulting firm involved in the field of sensory evaluation
offoods, beverages, pharmaceuticals, paper, fabrics, personal care, and other consumer
products. Sensory Spectrum provides guidance in the selection, implementation, and
analysis of test methods for solving problems in quality control, research, development,
production,andmarketing.Shehastrainedseveralflavorandtexturedescriptiveprofile
panels in her work with industry, universities, andgovernment.
As a course director for the Center for Professional Advancement and Sensory Spec-
trum, Ms. Civille has conducted several workshops and courses in basic sensory
evaluation methods as well as advanced methods and theory. In addition, she has been
invited to speak to several professional organizations on different facets of sensory
evaluation.
Ms.Civillehaspublishedseveralarticlesongeneralsensorymethodsaswellassophis-
ticateddescriptiveflavorandtexturetechniques.AgraduateoftheCollegeofMountSaint
Vincent, New York, with a B.S. in chemistry, Ms. Civille began her career as a product
evaluation analystwith theGeneral Foods Corporation.
B. Thomas Carr, M.A., is principal of Carr Consulting, Wilmette, Illinois, a research
consulting firm that provides project management, product evaluation, and statistical
support services to the food, beverage, personal care, and home care industries. He has
over18yearsofexperience inapplyingstatistical techniquestoallphasesofresearchon
consumerproducts.PriortofoundingCarrConsulting,Mr.Carrheldavarietyofbusiness
andtechnicalpositionsinthefoodandfoodingredientindustries.AsdirectorofContract
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