Consumer perception and acceptance of calorie- reduced dairy products Forbrukeroppfatninger og –aksept av kaloriredusert meieriprodukter Philosophiae Doctor (PhD) Thesis Susanne Bølling Johansen Dept. of Chemistry, Biology and Food Science Norwegian University of Life Sciences Ås 2010 Thesis number 2010: 03 ISSN 1503-1667 ISBN 978-82-575-0915-6 The fool doth think he is wise, but the wise man knows himself to be a fool. William Shakespeare (1564 - 1616) “As You Like It”, Act 5, Scene 1 Consumer perception and acceptance of calorie-reduced dairy products PhD Thesis 2010 © Susanne Bølling Johansen ISBN-nr.: 978-82-575-0915-6 ISSN-nr.: 1503-1667 Printed by CopyCat avd. Ski, Jernbaneveien 2, 1400 Ski, Norway ii Table of contents Acknowledgements..............................................................................................v Abstract.............................................................................................................vii Sammendrag (Norwegian abstract)...................................................................viii List of papers......................................................................................................ix Introduction.........................................................................................................1 1 Background..............................................................................................1 2 Aims of the study.....................................................................................3 3 Theory and approach...............................................................................5 3.1 Factors affecting consumer response...........................................................5 3.1.1 The stimulus.................................................................................5 3.1.2 The consumer perception.............................................................9 3.1.2.1 Reference basis...................................................................10 3.1.2.2 Expectations......................................................................12 3.2 Methodology......................................................................................13 3.2.1 Analytical methodology (trained assessors).................................13 3.2.1.1 Descriptive profiling...........................................................13 3.2.2 Affective methodology (consumers)...........................................14 3.2.2.1 Preference tests..................................................................14 3.2.2.2 Acceptance tests.................................................................15 3.2.3 Data analysis..............................................................................16 4 Main results and discussion....................................................................19 5 Challenges and future perspectives.........................................................21 References..........................................................................................................23 Abstracts of papers.............................................................................................31 Paper I-IV iii iv Acknowledgements This thesis was written at Nofima Mat in Ås under the supervision of Adjunct Associate Professor Margrethe Hersleth (principal supervisor, Nofima Mat and UMB), Principal Research Scientist Tormod Næs (co-supervisor, Nofima Mat) and Professor Judith Narvhus (co-supervisor, UMB). The work was conducted in the period of 2005-2009 as part of a user managed innovation project financed by the Research Council of Norway through Grant number 167928/I10 and conducted in collaboration with TINE BA. The motivation for this thesis is based on my interest in sensory science and the desire of studying and understanding the world of food. The thesis has given me the opportunity to develop my skills by including understanding of the final link in the chain of food consumption, thus the consumer. All papers in the thesis address important questions and problems, which have been raised as the work progressed and new discoveries were made, relating to different aspects in the understanding of consumption of calorie-reduced dairy products. First of all, I wish to express my sincere gratitude to all of my supervisors Dr. Margrethe Hersleth, Dr. Tormod Næs and Dr. Judith Narvhus. My deepest thanks go to Dr. Margrethe Hersleth for her highly encouraging supervision, valuable advice and daily talks. Dr. Tormod Næs is especially thanked for his experienced supervision, helpful comments and always positive attitude and spirit. My gratitude goes out to all my past and present colleagues. The people at the Sensory Science Group in Copenhagen who started my journey into Sensory Science, my fellow colleagues at “Toppetasjen” with whom I enjoyed many a happy moment and helpful scientific discussions, and my fellow Ph.D. students at Nofima Mat with whom I shard memorable social events. Dr. Øydis Ueland and Dr. Marit Rødbotten are especially thanked for their valuable comments. Thanks to Per Lea for answering my statistical questions. Thanks to Dr. Ulrike Böcker with whom I have had many discussions and joy about being a foreigner in Norway and to the “old lunch gang” Britt Signe Granli, Josefine Skaret, Asgeir Nikolai Nilsen and my office neighbour for years Dr. Oliver Tomic for making my work day even more fun. Finally, I would like to thank my family and friends in Denmark for their care, support and understanding during long periods without visiting. In particular my mother and sister for their unconditional love and acceptance of my situation and its necessary sacrifices have given me peace of mind to finish the thesis. My gratitude also goes to my fiancé Jakob for letting me undertake this project, although it halfway into the completion meant living apart in different countries. Love and thanks from the bottom of my heart. Ås, January 2010, Susanne Bølling Johansen v vi Abstract This thesis is a part of the research project ‘‘Low energy products and consumer preferences”, financed by the Research Council of Norway (NFR) through Grant 167928/I10. The thesis is based on three experiments. Consumers’ motivation for choice, and their healthiness perception of calorie-reduced dairy products, were examined in a cross-cultural study. Based on two experiments different consumer groups’ sensory acceptances were modelled, as well as the effect of providing additional nutritional information on these acceptances. The selected products throughout the project were calorie-reduced yoghurt and cheese. Results of all experiments and resulting articles are briefly stated below. One experiment investigated young consumers’ motivation for choice, and their healthiness perception of calorie-reduced yoghurt and cheese. The experiment was performed as a cross-cultural study in three countries: Denmark, Norway and US. The main findings in this study may be summarised as follows: • Overall, young consumers’ main motives for choosing calorie-reduced yoghurt and cheese were: low in fat content, keeps one healthy and tastes good. • Generally, calorie-reduced yoghurt and cheese were perceived as relatively healthy compared to other foods. • Minor cross-cultural differences were found in motives for choice and perceived healthiness of the products. However, the similarities between the countries were evident. Two experiments investigated consumers’ sensory acceptances of calorie-reduced yoghurt and cheese, respectively and the effect of giving nutritional information about the tested product on these acceptances. The most important findings from these experiments are: • The sensory properties were essential for acceptance of calorie-reduced yoghurt and low-fat cheese. • A greater diversity in sensory acceptance among the consumers was observed for low-fat cheese than for calorie-reduced yoghurt. • Sweetness had a major effect on acceptance of calorie-reduced yoghurt. • Nutritional information was shown to influence acceptance, and the effect seemed to be dependent on type of product and the sensory attributes that were important for acceptance. • Nutritional information generally increased acceptance of calorie-reduced yoghurt, while it decreased acceptance of low-fat cheese. Similar effects of information were not observed for the yoghurt and cheese with the highest hedonic ratings. vii Sammendrag (Norwegian abstract) Denne avhandlingen er en del av forskningsprosjektet ”Lavenergiprodukter med utgangspunkt i forbrukerpreferanser”, finansiert av Norges forskningsråd (NFR) gjennom 167928/I10. Avhandlingen er basert på tre forsøk. Forbrukeres motivasjon for valg og deres helseoppfatning av kalorireduserte meieriprodukter, ble undersøkt i en tverrkulturell studie. Basert på to eksperimenter ble ulike forbrukergruppers sensoriske aksept modellert, samt effekten av å gi ytterligere ernæringsinformasjon på denne aksepten. De utvalgte produktene i prosjektet var kaloriredusert yoghurt og ost. Resultatene av alle eksperimenter og de derav følgende artiklene er kort angitt nedenfor. Ett eksperiment undersøkte unge forbrukernes motivasjon for valg, og deres helseoppfatning av kaloriredusert yoghurt og ost. Eksperimentet ble utført som en tverrkulturell studie i tre land: Danmark, Norge og USA. Hovedfunnene in denne studie kan oppsummeres som følger: • Generelt var unge forbrukeres viktigste motiver for å velge kaloriredusert yoghurt og ost: lavt fettinnhold, at det holder en sunn og smaker godt. • Generelt ble kaloriredusert yoghurt og ost oppfattet som relativt sunt i forhold til andre matvarer. • Mindre tverrkulturelle forskjeller ble funnet i motiver for valg og helseoppfattningen av produktene. Imidlertid var det klare likheter mellom landene. To eksperimenter undersøkte forbrukernes sensoriske aksept av henholdsvis kaloriredusert yoghurt og ost, og effekten av å gi ernæringsinformasjon om de testede produktene på denne aksepten. De viktigste funnene fra disse eksperimentene er: • De sensoriske egenskaper var avgjørende for aksept av kaloriredusert yoghurt og lavfett ost. • Et større mangfold i sensorisk aksept blant forbrukerne ble observert for lavfett ost enn for kaloriredusert yoghurt. • Søthet hadde en stor effekt på aksept av kaloriredusert yoghurt. • Ernæringsinformasjon ble vist å påvirke aksept, og effekten synes å være avhengig av type produkt og sensoriske egenskaper som var viktige for aksepten • Generelt økte ernæringsinformasjonen aksepten av kaloriredusert yoghurt, mens den reduserte aksepten av lavfett ost. Lignende effekter av informasjon ble ikke observert for yoghurten og osten med høyest hedonisk bedømmelse. viii List of papers I. Johansen, S.B., Næs, T., and Hersleth, M. (2010). Motivation for choice and healthiness perception of calorie-reduced dairy products - a cross- cultural study. Accepted with revisions at Appetite. II. Johansen, S.B., Hersleth, M. and Næs, T. (2010). A new approach to product set selection and segmentation in preference mapping. Food Quality and Preference, 21(2), 188-196. III. Johansen, S.B., Næs, T., Øyaas, J. and Hersleth, M. (2010). Acceptance of calorie-reduced yoghurt: Effects of sensory characteristics and product information. Food Quality and Preference, 21(1), 13-21. IV. Johansen, S.B., Hersleth, M., Narvhus, J., Øyaas, J. and Næs, T. (2010). Effects of information about fat percentage on acceptance of low-fat cheese. Manuscript. ix x