UNIVERSIDADE ESTADUAL DE CAMPINAS
Faculdade de Engenharia de Alimentos
ERICK ALMEIDA ESMERINO
QUALITATIVE AND DESCRIPTIVE SENSORY EVALUATION
OF DIFFERENT COMMERCIAL FERMENTED DAIRY
PRODUCTS ACCORDING CONSUMERS’ AND TRAINED
ASSESSORS’ PERCEPTION
AVALIAÇÃO SENSORIAL QUALITATIVA E DESCRITIVA DE
DIFERENTES PRODUTOS LÁCTEOS FERMENTADOS
COMERCIAIS ATRAVÉS DA PERCEPÇÃO DE CONSUMIDORES
E ASSESSORES TREINADOS
CAMPINAS 2016
ERICK ALMEIDA ESMERINO
QUALITATIVE AND DESCRIPTIVE SENSORY EVALUATION
OF DIFFERENT COMMERCIAL FERMENTED MILK
PRODUCTS ACCORDING CONSUMERS’ AND TRAINED
ASSESSORS’ PERCEPTION
AVALIAÇÃO SENSORIAL QUALITATIVA E DESCRITIVA DE
DIFERENTES PRODUTOS LÁCTEOS FERMENTADOS
COMERCIAIS ATRAVÉS DA PERCEPÇÃO DE CONSUMIDORES
E ASSESSORES TREINADOS
CAMPINAS 2016
Thesis presented to the Faculty of Food Engineering in partial fulfillment of the requirements for the degree of Doctor in Food and Nutrition, in the area of Consumption and Food Quality.
Tese apresentada à Faculdade de Engenharia de Alimentos da Universidade Estadual de Campinas como parte dos requisitos exigidos para a obtenção do título de Doutor em Alimentos e Nutrição, na Área de Consumo e Qualidade dos Alimentos.
Supervisor/Orientadora: Prof.ª Dr. Helena Maria André Bolini
ESTE EXEMPLAR CORRESPONDE À VERSÃO FINAL DA TESE DEFENDIDA PELO ALUNO ERICK ALMEIDA ESMERINO, ORIENTADO PELA PROFA. DRA. HELENA MARIA ANDRÉ BOLINI.
Ficha catalográfica
Universidade Estadual de Campinas
Biblioteca da Faculdade de Engenharia de Alimentos Claudia Aparecida Romano - CRB 8/5816
Esmerino, Erick Almeida,
Es53q EsmQualitative and descriptive sensory evaluation of different commercial
fermented dairy products according consumers' and trained assessors' perception / Erick Almeida Esmerino. – Campinas, SP : [s.n.], 2016.
EsmOrientador: Helena Maria André Bolini.
EsmTese (doutorado) – Universidade Estadual de Campinas, Faculdade de
Engenharia de Alimentos.
Esm1. Produtos lácteos fermentados. 2. Percepção do consumidor. 3.
Pesquisa qualitativa. 4. Análise sensorial descritiva. 5. Métodos temporais. I. Bolini, Helena Maria André. II. Universidade Estadual de Campinas. Faculdade de Engenharia de Alimentos. III. Título.
Informações para Biblioteca Digital
Título em outro idioma: Avaliação sensorial qualitativa e descritiva de diferentes produtos lácteos fermentados comerciais através da percepção de consumidores e assessores treinados
Palavras-chave em inglês: Fermented dairy products Consumer perception Qualitative research
Descriptive sensory analysis Temporal methods
Área de concentração: Consumo e Qualidade de Alimentos Titulação: Doutor em Alimentos e Nutrição
Banca examinadora:
Helena Maria André Bolini [Orientador] Adriano Gomes da Cruz
Diogo Thimoteo da Cunha Eliene Penha Rodrigues Pereira Leila Maria Spadoti
Data de defesa: 09-12-2016
Programa de Pós-Graduação: Alimentos e Nutrição
BANCA EXAMINADORA
__________________________________________
Profa. Dra. Helena Maria André Bolini
Orientadora FEA - UNICAMP
__________________________________________
Prof. Dr. Adriano Gomes da Cruz
Membro Titular DCTA - IFRJ
_________________________________________
Prof. Dr. Diogo Thimoteo da Cunha
Membro Titular FCA – UNICAMP/Limeira
__________________________________________
Dra. Eliene Penha Rodrigues Pereira
Membro Titular Pesquisadora Independente
__________________________________________
Dra. Leila Maria Spadoti
Membro Titular TECNOLAT - ITAL
__________________________________________
Prof. Dr. Marco Antônio Trindade
Membro Suplente FZEA – USP
__________________________________________
Profa. Dra. Mônica Queiroz de Freitas
Membro Suplente DTA – UFF
__________________________________________
Prof. Dr. Wellington de Freitas Castro
Membro Suplente DCTA – IFSP/Barretos
A ATA DA DEFESA COM AS RESPECTIVAS ASSINATURAS DOS MEMBROS ENCONTRA-SE NO PROCESSO DE VIDA ACADÊMICA DO ALUNO.
DEDICATÓRIA
Dedico este trabalho aos meus pais João e Andréia,
à minha avó Maria Lidia e aos meus irmãos Alison, Nikollas e Vitor.
AGRADECIMENTOS
Aos meus familiares pelo amor, incentivo e apoio incondicional;
À Profª Dra. Helena Bolini pela orientação, confiança, amizade e exemplo de profissionalismo;
Àqueles, que dе forma especial е carinhosa, mе deram força е suporte: Paulinho, Mônica, Verônica e Paulo;
Aos amigos Chris, Erika, Fabíola, Viviane, Valéria, Elaine, Ricardo, Rodrigo e Flavinny por entenderem a minha ausência, e me incentivarem a seguir neste caminho;
Aos amigos Juliana (Wolva), Adriano, Elson, Geina e Alê pela grande amizade, companheirismo, além da essencial ajuda e compreensão no desenvolvimento deste trabalho;
Aos amigos Ana Laura, Amanda, Débora, Nina, Bruna e Ju Alves pela amizade e os constantes momentos de descontração dentro e fora do ambiente de trabalho;
Aos colegas e funcionários do Laboratório de Análises Sensorial, pelo apoio, ajuda e colaboração para execução deste projeto;
Aos professores, alunos e funcionários do Departamento de Alimentos e Nutrição (especialmente Cidinha e Suzana), pelo agradável ambiente de trabalho;
A todos os provadores pela dedicação, paciência e disposição para realização dos testes, sem as quais não seria possível a realização do estudo;
Aos membros da banca examinadora pelas contribuições e sugestões apresentadas;
Ao CNPq, pela concessão de bolsa e auxílio que colaboraram para a existência deste trabalho.
"Desaprender para aprender. Deletar para escrever em cima. Houve um tempo em que eu pensava que, para isso, seria preciso nascer de novo, mas hoje sei que dá pra renascer várias vezes nesta mesma vida.
Basta desaprender o receio de mudar".
RESUMO GERAL
Iogurtes líquidos, bebidas lácteas fermentadas e leites fermentados possuem grande similaridade sensorial e aceitação, entretanto, os fatores que influenciam a escolha de cada um desses produtos são desconhecidos. Neste sentido, o presente trabalho teve por objetivos: (1) identificar os principais fatores envolvidos na escolha e consumo dos diferentes produtos através de métodos qualitativos e projetivos – Grupos Focais, Teste de Associação de Palavras e Mapa Projetivo; (2) investigar o impacto de características intrínsecas e extrínsecas sobre as respostas emocionais e aceitação através do método de Perfil Livre; (3) verificar a efetividade do método Pivot Profile na caracterização sensorial e determinação dos direcionadores de preferência; (4) determinar o perfil sensorial dinâmico através dos métodos Temporal Dominance of Sensations (TDS), Progressive Profiling e Temporal Check-all-that-apply (TCATA); e (5) caracterizar amostras de iogurte Grego utilizando os métodos Pivot Profile, CATA e Mapa Projetivo. Os resultados indicaram que a diferenciação dos produtos possui estreita relação com fatores sensoriais, emocionais, percepção de benefícios, entre outros. Nota-se ainda que o desconhecimento é grande sobre a diferenciação do produto “bebida láctea fermentada” em relação aos demais. Observou-se que as informações técnicas sobre os diferentes produtos não influenciaram sua aceitação, porém exerceram grande efeito sobre seus perfis emocionais, principalmente sobre bebida láctea fermentada, que devido às informações exigidas em sua rotulagem, sofreu forte dissociação da imagem do iogurte. O trabalho ainda determinou o perfil sensorial descritivo e Mapa Externo de Preferência utilizando método rápido, apresentando resultados equivalentes ao gerado por assessores treinados; e o perfil sensorial dinâmico, que captou as variações decorrentes do processamento oral e evidenciou a estreita relação entre os métodos utilizados. Devido à salientada importância comercial, amostras de iogurte Grego também foram, com sucesso, caracterizadas através das diferentes metodologias. Concluiu-se que a escolha dos diferentes produtos lácteos fermentados é multifatorial, evidenciando a necessidade de melhorias na comunicação e informação dos diferentes produtos lácteos fermentados de forma que sejam realizadas escolhas mais conscientes pelos consumidores. Quanto às características sensoriais, não foram observadas tendências relacionadas às categorias dos produtos, sendo as principais diferenças relacionadas com suas identidades comerciais.
Palavras-chave: Produtos lácteos fermentados, percepção do consumidor, pesquisas
ABSTRACT
Liquid yogurts, fermented milk beverages, and fermented milk have great sensory similarity and acceptance; however, the factors affecting consumers' choice are unknown. In this sense, this study aimed to: (1) identify the main factors involved in the choice and consumption of different products, through the qualitative and projective methods Focus Group, Word Association Task, and Projective Mapping; (2) investigate the impact of intrinsic and extrinsic characteristics on the acceptance and emotional responses using the Free-Choice Profile method; (3) verify the effectiveness of Pivot Profile method for the sensory characterization and determination of the drivers of preference; (4) determine the dynamic sensory profile through Temporal Dominance of Sensations (TDS), Progressive Profiling, and Temporal Check-all-that-apply (TCATA); and (5) characterize Greek yogurt samples using the Pivot Profile, Check-all-that-apply (CATA), and Projective Mapping. The results indicated that the differentiation of products is closely related to the sensory and emotional factors, the perception of benefits, among others. A great unfamiliarity was observed for differentiation of fermented milk beverage when compared to the others. Although the technical information about the different products did not affect acceptance, it exerted a great effect on the emotional profiles, especially for the fermented milk beverage, which was strongly dissociated from the image of yogurt due to the information on its mandatory labeling. The study also determined the descriptive sensory profile and External Preference Mapping using a rapid method, with similar results to those generated by trained assessors, besides the dynamic sensory profile, which captured the variations arising from oral processing and highlighted the close relationship between the methods. Greek yogurt samples were also successfully characterized by the different methodologies due to its highlighted commercial importance. It was concluded that the choice of different fermented milk products is multifactorial, thus requiring improvements in communication and information about different fermented milk products, focused on a conscious choice by consumers. With respect to the sensory characteristics, no tendencies related to the categories of products were observed, since the main differences were related to their commercial identity.
Keywords: Fermented dairy products, consumer’s perception, qualitative research, sensory
SUMÁRIO
1. INTRODUÇÃO GERAL ... 14
2. OBJETIVOS ... 17
ARTICLE 1: CONSUMERS’ PERCEPTIONS TOWARDS THREE DIFFERENT FERMENTED DAIRY PRODUCTS: INSIGHTS FROM FOCUS GROUPS, WORD ASSOCIATION AND PROJECTIVE MAPPING ... 18
1. INTRODUCTION ... 20
2. MATERIAL AND METHODS... 22
2.1SAMPLES ... 22
2.1.1 Definition of Stimuli ... 22
2.2.2 Word Association Task ... 23
2.2.3 Projective Mapping ... 24
2.3DATA ANALYSIS ... 25
2.3.1 Focus Groups ... 25
2.3.2 Word Association Task (WA) ... 25
2.3.3 Projective Mapping (PM)... 26
3. RESULTS ... 26
3.1FOCUS GROUP ... 26
3.2WORD ASSOCIATION TASK (WA) ... 32
3.3PROJECTIVE MAPPING ... 36
4. DISCUSSION ... 38
5. CONCLUSIONS ... 42
6. REFERENCES ... 43
ARTICLE 2: EMOTIONAL FREE CHOICE PROFILE: A NEW PROPOSAL TO EVALUATE CONSUMERS’ EMOTION USING A VERSATILE AND ALTERNATIVE TOOL ... 52
1. INTRODUTION ... 54
2. MATERIAL AND METHODS... 55
2.1SAMPLING ... 55
2.2CONSUMERS ... 56
2.3SENSORY AND EMOTIONAL EVALUATION ... 56
2.3.1 Experimental Design of the Emotional Free-Choice Profiling (EFCP) ... 57
2.3.1.2 Informed Condition ... 57
2.3.2 Acceptance Test ... 58
2.3.4 Informational stimuli ... 58
2.4STATISTICAL ANALYSIS ... 59
2.4.1 ANOVA and paired t- test... 59
2.4.2 Generalized Procrustes Analysis (GPA) ... 60
2.4.3 Similarity between Emotional Settings ... 60
3. RESULTS AND DISCUSSION ... 60
3.1ACCEPTANCE TEST ... 60
3.2EMOTIONAL FREE-CHOICE PROFILE ... 61
3.2.1 Blind condition ... 61
3.2.2 Informed condition ... 63
3.3SIMILARITY BETWEEN EMOTIONAL SETTINGS ... 64
4. CONCLUSIONS ... 69
6. REFERENCES ... 70
ARTICLE 3: REFERENCE-BASED PREFERENCE MAPPING: AN ALTERNATIVE APPROACH TO UNDERSTAND CONSUMER’S PREDILECTION USING PIVOT PROFILE ... 77
1. INTRODUCTION ... 79
2. MATERIAL AND METHODS... 81
2.1SAMPLES ... 81
2.2SENSORY EVALUATION ... 81
2.2.1 Quantitative Descriptive Analysis (QDA) ... 81
2.2.2 Acceptance Test ... 82
2.2.3 Pivot Profile ... 82
2.3STATISTICAL ANALYSIS ... 84
2.3.1 Quantitative Descriptive Analysis (QDA) ... 84
2.3.2 Acceptance Test ... 84
2.3.3 Pivot Profile ... 85
2.3.4 Graphic analysis of Pivot Profile ... 85
2.3.5 Similarity between the Sensory Configurations ... 86
3. RESULTS AND DISCUSSION ... 86
3.1QUANTITATIVE DESCRIPTIVE ANALYSIS (QDA) ... 86
3.3PIVOT PROFILE ... 92
3.4SIMILARITY BETWEEN THE SENSORY CONFIGURATIONS OF THE SAMPLES ... 98
4. CONCLUSION ... 100
5. REFERENCES ... 102
ARTICLE 4: UNDERSTANDING DYNAMIC PERCEPTIONS OF DIFFERENT FERMENTED DAIRY PRODUCTS: A TEMPORAL PROFILING STUDY USING TEMPORAL CHECK-ALL-THAT-APPLY (TCATA), TEMPORAL DOMINANCE OF SENSATIONS (TDS) AND PROGRESSIVE PROFILE (PP) ... 111
1. INTRODUCTION ... 113
2. MATERIAL AND METHODS... 115
2.1SAMPLES ... 115
2.2PARTICIPANTS ... 115
2.3SENSORY EVALUATION ... 115
2.3.1Temporal Dominance of Sensation (TDS) ... 116
2.3.2 Progressive Profile (PP) ... 116
2.3.3 Temporal Check-all-that-apply (TCATA) ... 116
2.4STATISTICAL ANALYSIS ... 117
2.4.1 Temporal Dominance of Sensations (TDS) ... 117
2.4.2 Progressive Profile ... 117
2.4.3 Temporal Check-all-that-apply (TCATA) ... 117
2.4.4 Principal Components Analysis (PCA ... 118
2.4.5 Similarity between the Sensory Settings ... 118
3. RESULTS ... 118
3.1TEMPORAL DOMINANCE OF SENSATIONS (TDS) ... 118
3.2PROGRESSIVE PROFILE (PP) ... 120
3.3TEMPORAL CHECK-ALL-THAT-APPLY (TCATA) ... 123
3.4PRINCIPAL COMPONENT ANALYSIS (PCA) AND TRAJECTORY MAPS ... 125
3.5SIMILARITY BETWEEN THE SENSORY SETTINGS ... 126
4. DISCUSSION ... 127
5. CONCLUSION ... 131
6. REFERENCES ... 132
ARTICLE 5: COMPARISON OF SENSORY PRODUCT PROFILES USING PIVOT PROFILE, PROJECTIVE MAPPING AND CHECK-ALL-THAT-APPLY (CATA): HOW DO CONSUMERS PERCEIVE GREEK YOGURT? ... 137
1. INTRODUCTION ... 139
2. MATERIAL AND METHODS... 141
2.1SAMPLES ... 141 2.2CONSUMERS ... 141 2.3SENSORY EVALUATION ... 141 2.3.1 Projective Mapping ... 142 2.3.2 Check-all-that-apply – CATA ... 142 2.3.3 Pivot Profile ... 142
2.4EASE IN PERFORMING THE TESTS... 143
2.5STATISTICAL ANALYSIS ... 143
2.5.1 Projective Mapping ... 143
2.5.2 Check-all-that-apply (CATA) ... 144
2.5.3 Pivot Profile ... 144
2.5.4 Graphic analysis of CATA and Pivot Profile ... 145
2.5.6 Similarity between the Sensory Configurations ... 145
2.5.7 Hierarchical cluster analysis ... 145
2.5.8 Analysis of Variance (ANOVA) ... 146
3. RESULTS AND DISCUSSION ... 146
3.1PROJECTIVE MAPPING ... 146
3.2CHECK-ALL-THAT-APPLY (CATA) ... 147
3.3PIVOT PROFILE ... 150
3.4SIMILARITY BETWEEN THE SENSORY CONFIGURATIONS ... 153
3.5 EASE IN PERFORMING THE TESTS ... 156
4. CONCLUSIONS ... 159 5. REFERENCES ... 161 3. DISCUSSÃO GERAL ... 169 4. CONCLUSÕES GERAIS ... 174 5. REFERÊNCIAS BIBLIOGRÁFICAS ... 176 APÊNDICES ... 206 ANEXO ... 208
1. INTRODUÇÃO GERAL
O mercado oferece inúmeros produtos lácteos fermentados, similares em aparência, coloração e textura, mas com pontuais diferenças tecnológicas e na qualidade nutricional (Zhu et al., 2009; Janiaski et al., 2016). Dentre estes, destacam-se os iogurtes, as bebidas lácteas fermentadas e os leites fermentados, produtos bem familiares à população e de benefícios amplamente conhecidos (Newsholme, 2002; Lollo et al., 2013; Morell et al., 2015).
O iogurte apresenta um papel importante nos hábitos alimentares de diversas nações, independentemente do nível de desenvolvimento socioeconômico (De Almeida et al., 2006; Han et al., 2015). Tem sido reconhecido como um alimento de reputação positiva na memória dos consumidores, considerado pela maioria como um alimento saudável (Barrios et
al., 2008). Por terem sua imagem associada a do iogurte, e com características sensoriais
(aparência, acidez e consistência) similares, as bebidas lácteas fermentadas e leites fermentados têm apresentado grande aceitação e crescimento comercial (Achanta et al., 2007; Zhu et al., 2009; Gomes et al., 2013; Janiaski et al., 2016).
Embora os nomes sejam claramente distintos, as diferenças entre esses produtos não são óbvias para os consumidores. Suas embalagens são muito semelhantes e os ingredientes utilizados são praticamente os mesmos, entretanto, as composições de cada um apresentam diferenças nutricionais importantes (Castro et al., 2013a; 2013b). Segundo Vieira
et al. (2007), em pesquisa com 500 consumidores, observou-se que 83% dos entrevistados
desconheciam produtos que possuíam soro de queijo como um dos ingredientes principais; apenas 13% sabiam a diferença entre bebida láctea e leite UHT; e apenas 11% sabiam sobre a diferença entre bebida láctea fermentada e iogurte.
Teoricamente, os critérios adotados pelos consumidores na escolha destes produtos e que garantem seu sucesso comercial não podem ser explicados somente por diferenças perceptíveis na qualidade sensorial (Barrios et al., 2008; Bayarri et al., 2011; Hoppert et al. 2012; Booth, 2014; Sosa et al. 2015; Alemu et al., 2017). Apelos nutricionais e de saúde, por exemplo, podem criar imagens favoráveis influenciando positivamente a escolha de um produto (Bayarri et al., 2010; Carrilllo et al., 2014; Schouteten et al., 2015; Morais et al., 2015).
Esses critérios têm sido descritos como uma relação complexa entre características sensoriais (aparência, aroma, sabor e textura) e não sensoriais como: conceitos do produto, preço, conveniência e marca (Ares et al., 2010; Trendel e Werle, 2016), onde compreender esses fatores tem sido um enorme desafio para os pesquisadores da área de sensorial (Valentin et al., 2012; Varela et al., 2014; Schouteten et al., 2015).
Estudos averiguando o impacto de fatores não sensoriais sobre a percepção dos consumidores têm apresentado crescimento nos últimos anos, com abordagens metodológicas diversas (Ares et al., 2010; Mojet et al., 2015; Masson et al., 2016; Lagerkvist et al., 2016). Neste intuito, métodos qualitativos têm sido empregados com sucesso por profissionais de marketing e pesquisa de consumidor (Carey, 2015). Através da grande quantidade de informação semântica fornecida, essas metodologias permitem uma sondagem profunda do comportamento do consumidor (Lawless e Heymann, 2010). São apropriadas para identificar oportunidades de mercado, gerar ideias e hipóteses, explorar e desenvolver novos conceitos, e compreender as perspectivas de consumo anteriores à pesquisa quantitativa (Jervis e Drake, 2014).
Entretanto, o entendimento de fatores não sensoriais por si só não garante o sucesso de um produto. Para uma compreensão completa, as propriedades sensoriais também devem ser cuidadosamente investigadas (Siró et al., 2008; Hoppert et al., 2012; Varela, 2015; Lagerkvist et al., 2016). A determinação do perfil sensorial de um produto é uma ferramenta importante para a indústria, pois através de técnicas adequadas é possível obter informações relevantes para o desenvolvimento, marketing, e reformulação de produtos já existentes (Meilgaard et al., 1999; Ares et al., 2016; Fonseca et al., 2016). Dentre as técnicas empregadas, a Análise Descritiva Quantitativa (ADQ) é o método mais utilizado para a caracterização sensorial de alimentos (Varela e Ares, 2012; Stone, 2015), e com sucesso, diversos autores têm determinado o perfil sensorial dos mais variados produtos (Cadena et al., 2012; Morais et al., 2015; Devezeaux de Lavergne et al., 2015; Braghieri et al., 2016).
Embora os resultados obtidos pela ADQ sejam mais detalhados, consistentes e robustos, algumas desvantagens devem são ressaltadas (Valentin et al., 2012; Cruz et al., 2013). A técnica tem uma abordagem demorada e onerosa, principalmente devido à etapa de treinamento dos participantes envolvidos na avaliação (Dehlholm et al., 2012; Ares et al., 2015; Fonseca et al., 2016). Além disso, o alto grau de treinamento e especialização levam os
assessores a descrever o produto de forma muito criteriosa, considerando atributos que podem ser irrelevantes à percepção dos consumidores (Symoneaux et al., 2012; Varela et al., 2014; Fonseca et al., 2016). Por esta razão, recomenda-se que a opinião dos consumidores deve ser considerada, não somente na avaliação do produto final, mas também durante todo o processo de desenvolvimento de um produto (Bruzzone et al., 2015; Pelsmaeker et al., 2015).
Por décadas, os consumidores têm sido considerados apenas capazes de emitir informações hedônicas (Meilgaard et al., 1999; Fonseca et al ., 2016). No entanto, segundo Moskowitz (1996), os consumidores são capazes de avaliar e classificar aspectos sensoriais dos produtos, apresentando resultados altamente correlacionados com os obtidos por assessores treinados.
Essa hipótese vem sendo aceita dentro da comunidade científica (Moussaoui e Varela, 2010; Valentin et al., 2012) e técnicas rápidas de caracterização sensorial, como Flash Profile, Check-all-that-apply (CATA) e Mapa Projetivo, baseadas na percepção dos consumidores, têm sido desenvolvidas e se tornado cada vez mais populares na última década (Varela e Ares et al., 2012; Valentin et al., 2012; Ares et al., 2015; Vidal et al., 2016; Galmarini et al., 2016). Além disso, essas técnicas fornecem, de maneira rápida e econômica, uma descrição sensorial rápida dos produtos sendo particularmente interessante para as grandes empresas, devido a sua enorme gama de produtos, e também companhias de menor porte, onde seus recursos são limitados (Cruz et al., 2013; Fonseca et al., 2016).
Destaca-se ainda que apesar do sucesso de vendas e popularidade (Bong e Moraru, 2014; Gyawali e Ibrahim, 2016), escassos estudos tiveram como objetivo a investigação sensorial de iogurtes Gregos (Desai et al., 2013). Como os padrões de identidade e qualidade de iogurtes Gregos ainda não são bem definidos, uma variedade de ingredientes é permitida na formulação (Desai et al., 2013). Dessa forma, investigações dessa abrangência podem trazer importantes contribuições para as indústrias produtoras deste tipo de alimentos.
Diante de todo o proposto, fica evidenciada a necessidade de uma investigação aprofundada sobre os diferentes produtos lácteos fermentados e sua relação com os consumidores, analisando de forma detalhada que fatores intrínsecos e extrínsecos influenciam a escolha e consumo desses produtos pelos seus consumidores, fornecendo sugestões para a formulação, reformulação e melhoria das informações prestadas ao
consumidor. Neste sentido, metodologias qualitativas, projetivas e de caracterização sensorial rápida podem ser muito úteis.
2. OBJETIVOS
O presente trabalho teve por objetivos: (1) identificar os principais fatores envolvidos na escolha e consumo dos diferentes produtos através de métodos qualitativos e projetivos – Grupos Focais, Teste de Associação de Palavras e Mapa Projetivo; (2) investigar o impacto de características intrínsecas e extrínsecas sobre as respostas emocionais e aceitação utilizando o método Perfil Livre; (3) verificar a efetividade do método Pivot Profile na caracterização sensorial e determinação dos direcionadores de preferência; (4) determinar o perfil sensorial dinâmico através dos métodos Temporal Dominance of Sensations (TDS), Progressive Profiling e Temporal Check-all-that-apply (TCATA); e (5) caracterizar amostras de iogurte Grego utilizando os métodos Pivot Profile, CATA e Mapa Projetivo.
Com exceção da avaliação sensorial de iogurtes Gregos, todos os estudos foram pautados na diferenciação teórica e/ou sensorial de diferentes amostras comerciais de iogurtes prontos para beber, bebidas lácteas fermentadas e leites fermentados.
ARTICLE 1: Consumers’ Perceptions towards Three Different Fermented Dairy Products: Insights from Focus Groups, Word Association and Projective Mapping
Erick A. Esmerino1, Juliana P. Ferraz1, Elson R. Tavares Filho1, Mônica Q. Freitas2, Adriano
G. Cruz3, Helena M. A. Bolini1
1State University of Campinas (UNICAMP), Food and Nutrition Department, Cidade Universitária “Zeferino Vaz”, s/n, Campinas, São Paulo, Brazil, 13083-862
2 Federal Fluminense University (UFF), Food Technology Department, Rua Senador Furtado, nº 121/125, Niterói, Rio de Janeiro, Brazil, 20270-021
3 Federal Institute of Rio de Janeiro (IFRJ), Food Department, Rua Senador Furtado, nº 121/125, Maracanã, Rio de Janeiro, Brazil, 20270-021
* The manuscript has been successfully submitted online and is presently being given full consideration for publication in Journal of Sensory Studies.
* Corresponding Author
Erick Almeida Esmerino
erick.almeida@hotmail.com
Tel: (+55) 19 3521-4059 Fax: (+55) 19 3521-4060
ABSTRACT
Yogurts, fermented milk beverages, and fermented milks have great similarity and are widely accepted by Brazilian population but the factors that influence the choice of each product is unknown. In this sense, the present study aimed to identify the main aspects involved in consumers’ perception in relation to three different fermented dairy products (yogurts, fermented milk beverages and fermented milks) using methods with different qualitative nature (Focus Group, Word Association Task, and Projective Mapping). Through graphic stimuli, it was possible to identify numerous intrinsic and extrinsic factors. Greater impact dimensions were closely related to sensory aspects, emotional factors, perception of benefits, composition, among others. It is noteworthy that the stimuli relating to fermented milk beverages evoke dimensions indicating the rejection of the product, possibly by dissociation between information and consumers’ expectation. Although the methods have shown minor differences between the numbers of dimensions, important categories were found consensually, demonstrating the appropriation of qualitative and projective methods for investigation of consumers’ perception.
PRATICAL APPLICATIONS
The methods used in the current work showed very similar results and proved suitable as rapid low-cost alternatives to access consumer’s perception providing subsidies and guidelines for the reformulation of different fermented dairy products, marketing strategies, and improvement in communication between producers and consumers of different fermented dairy products. Our findings may be singularly interesting for small Brazilian production units, which have limited financial resources, and lack of a technical staff able to be solely responsible for these tasks.
Keywords: Consumers’ perception, qualitative research, projective techniques, focus group,
1. INTRODUCTION
To develop products that meet consumers` desires, studies on consumers` perceptions, attitudes, beliefs, feelings, and needs are highly recommended (Guerrero et al., 2010; de Andrade et al., 2016). The assessment of consumers` behavior can provide a deep and accurate understanding of the factors influencing their choices (Kourouniotis et al., 2016). Qualitative methods are defined as social research tools, highlighting particular contexts and exploring the opinions and perceptions of the participants, requiring little or no training sessions (Jervis & Drake, 2014). These methods facilitate the understanding of both the emotional responses and other complex factors not evidenced through quantitative studies (Harris et al., 2009). Through its versatile and flexible nature various dimensions can be exploited in depth, outside the context of structured quantitative studies (Jervis & Drake, 2014).
Among the traditional methods of qualitative research, Focus Group stands out for being considered an important tool in the early stages of development and consumer research (Massey, 2011; Carey, 2015; Morgan et al., 2016). It is based on group meetings, stimulated carefully by a moderator, in comfortable and friendly environment, extracting opinions and concepts in-depth understanding about a subject (Krueger & Casey, 2014; Eldesouky & Mesias, 2014). Moreover, new exploration methods have been imported from other areas, with prominence for application in the sensory science (Ares & Deliza, 2010; Viana et al., 2016). In this context, projective techniques have become increasingly popular among researchers (Vidal et al., 2013; Masson et al., 2016).
These approaches involve the use of vague, ambiguous, and unstructured stimuli or situations where the subject "projects his personality, attitude, opinions, and self-concepts to give the situation some structure (Donoghue, 2000). They simplify and provide a complex understanding of the attitudes of participants (Ramsey, 2006). There are five types of projective techniques: association, construction, completion, expressive technique, and choice based on ordering and grouping (Gordon & Langmaide, 1988). They are considered non-invasive approaches, thus accessing private conscious and unconscious of a person, which facilitate spontaneous verbalization of the most important representations of the stimulus, revealing the factors that affect the choice and product differentiation (Guerrero et al., 2010; Eldesouky et al., 2015).
Word Association Task (WA) is one of the most popular methods in exploratory research. By using spontaneous responses, it has shown positive results in the analysis of various foods (Rodrigues et al., 2015; De Andrade et al., 2016) and other product categories including cosmetics (Gámbaro et al., 2014). The technique consists of providing a verbal or visual stimulus that indirectly encourages participants to reveal their associations to a stimulus (Piqueras-Fiszman et al., 2013; Masson et al., 2016).
Projective Mapping (PM) is a holistic methodology widely used in the sensory characteristics of foods (Risvik et al., 1994; Vidal et al., 2014; Marcano et al., 2015; Pereira et al., 2016), despite having scarce studies to obtain data on consumer perceptions (Varela et al., 2014; Fiszman et al., 2015). Some studies have addressed the application of Projective Mapping of non-taste stimuli, with greater representation in recent years (Carrillo et al., 2012; Delholm et al., 2012; Mielby et al., 2014; Varela et al., 2014; Fizsman et al., 2015; Zhang et al., 2016).
Various fermented dairy products have been found in market, which may be similar in appearance, color and texture, but with technological differences and nutritional quality (Bayarri et al., 2010; Castro et al., 2013a; Janiaski et al., 2016). Yogurt plays an important role in eating habits of various nations (Donovan & Shamir, 2014; Pérez-Esteve et al., 2016), and has been recognized as a positive reputation in the minds of consumers (Muniandy et al., 2016). Fermented milk beverages and fermented milk have shown good consumers’ acceptability due to their image associated with yogurt (Castro et al., 2013b).
Despite their nomenclature is clearly distinct, they have similar packaging, practically the same ingredients, which make their differences not so obvious. As the selection and consumption of food is a highly complex phenomenon, influenced by sensory and non-sensory characteristics such as price, convenience, and brand to understand consumers’ needs and behavior under different fermented dairy products is a key factor for the commercial success of products (King et al., 2010; Santosa et al., 2013; Spinelli et al., 2015).
Thus, this study aimed to study the use of different exploratory and qualitative techniques to understand the complex factors affecting consumers’ choice and consumption of three different fermented dairy products - yogurt, fermented milk beverage (whey-based) and fermented milk - using Focus Group, Word Association Task (WA), and Projective Mapping
(PM). Although there are reports of using different qualitative methods in food research, the comparison between projective methodologies as WA and PM, and qualitative methods as Focus Groups was not found in literature.
2. MATERIAL AND METHODS
2.1 Samples
2.1.1 Definition of Stimuli
Eight cards were used as a stimulus for Word Association and Projective Mapping (Mielby et al., 2014; Zhang et al., 2016). Whereas the sensory characteristics and product packaging were very similar, each card was made up of an identical image of a pink milk beverage, with different specifications as technical nomenclature and specifications of Brazilian legislation (Brasil, 2005; 2007). The cards were printed in color images, and protected by a transparent adhesive paper. Stimuli are shown in Figure 1.
The information was written in the same font and size, differentiated only by the information provided by each product, ensuring that any impact on the parameters would occur because the messages provided, as follows: WYOG (full fat yogurt), SKYOG (low-fat yogurt), SPYOG (probiotic yogurt + definition of probiotics according to FAO/WHO, 2002), WFM (full fat fermented milk), SKFM (low-fat fermented milk), PFM (probiotic fermented milk+ definition of probiotics according to FAO/WHO, 2002), FMB (fermented milk beverage + milk beverage is not yogurt + it contains whey), and PFMB (probiotic fermented milk beverage + milk beverage is not yogurt + it contains whey + definition of probiotics according to FAO/WHO, 2002).
Figure 1. Representation of the eight stimuli used in Word Association Task and Projective
Mapping. From left to right: WYOG (full-fat yogurt), SKYOG (low-fat yogurt), PYOG (probiotic yogurt), FMB (fermented milk beverage), PFMB (probiotic fermented milk beverage), WFM (full-fat fermented milk), SKFM (low-fat fermented milk), PFM (probiotic fermented milk).
2.2.2 Word Association Task
Participants (n = 50) were instructed how to perform the Word Association task, and the tests were conducted in individual cabins with temperature and adequate lighting ensuring the comfort and privacy of participants. First, participants answered a brief
socio-demographic questionnaire, and then indicated the degree of familiarity with the three product categories (yogurts, fermented dairy beverages and fermented milk). The responses were obtained through a structured 5-point scale, where 1 = never heard and 5 = extremely familiar (Giacalone & Jaeger, 2016).
Then, the stimuli were provided randomly coded with three-digit random number. In possession of the card (stimulus), participants were asked to write the fourth first thoughts, words, feelings, images, and associations that came into their minds when they see and read each card with the respective information (Fiszman et al., 2015).
Table 1: Gender, age and education level of the participants that performed the three qualitative studies on different fermented dairy products.
Focus Groups Word Association Projective Mapping
GENDER (%) Men 35.0 30.0 32.0 Women 65.0 70.0 68.0 AGE (Years) Mean 31.5 30.6 32.1 Standard Deviation 8.5 9.1 8.9 EDUCATION (%) Undergraduate 35.0 14.0 10.0 Graduate 19.0 54.0 62.0 Postgraduate 46.0 32.0 28.0 2.2.3 Projective Mapping
To obtain spontaneous information about the different fermented dairy products, fifty participants, distinct to those who performed the WA task, under similar conditions of Section 2.2.2, were instructed to perform the PM and analysis of different stimuli. Similarly, participants completed a brief socio-demographic questionnaire, and indicated the degree of familiarity with the product under study.
Then the assessors received simultaneously eight cards (encoded with three random digits each), and were asked to place them on A4 white sheet of paper (210 x 297 mm), according to the similarities and dissimilarities between the products and information of stimuli. Participants used own criteria, with no right or wrong answers. It was explained that two stimuli placed near the sheet corresponded to similar perceptions, while different perceptions should be placed apart from each other (Carrillo et al., 2012; Mielby et al., 2014). After positioning of the samples, participants were asked to write on the sheet of paper, next to stimuli, all terms that came into their minds and helped differentiating each product or group of products (Varela et al., 2014).
2.3 Data Analysis
2.3.1 Focus Groups
Both Focus Groups were audio-recorded and transcribed in full by one of the authors, removing any identifying information about participants. Data were analyzed by thematic analysis (Barrios et al., 2008; Santosa et al., 2013). Two researchers present in the Focus Groups assessed the transcriptions, and consensually identified the most relevant points of the interviews.
2.3.2 Word Association Task (WA)
First, the results obtained by WA were analyzed qualitatively. All associations made by the participants were considered, and the most recurring terms were selected. After textual analysis, categorization of the terms was carried out, and terms with similar content were grouped in the same category (de Andrade et al., 2016; Masson et al., 2016). The categories were considered for analysis if their terms have been mentioned by more than 5% of the participants.
These procedures were conducted by two researchers and all results were categorized accordingly, resulting in 15 final categories. A global test, Chi-square, was used to analyze the differences in frequency of mention among the categories. Moreover, cell chi-square test been used within each pair of cells to identify sources of variation and significant differences (Symoneaux et al., 2012; Fonseca et al., 2016). Then, correspondence analysis
(CA) was applied to the WA frequency table, thus explaining the clear relationship between the categories and stimuli.
Data obtained in the evaluation of the level of familiarity of participants in WA and PM were subjected to Analysis of Variance (ANOVA), and significant differences were analyzed by Tukey’s test. The probability level of p<0.05 was considered statistically significant in the analysis
2.3.3 Projective Mapping (PM)
Data were obtained from the Cartesian coordinates X and Y of each stimulus for each participant, considering the lower left corner as the origin of the coordinate system. Multiple Factors Analysis (MFA) was used considering the coordinate values of the samples in each individual map generated by the participants (Pagès, 2005; Valentin et al., 2012). MFA belongs to the group of the so-called multiblock tecniques (Abdi et al., 2013). It provides information about the “consensus” product configuration, which in practical terms represents the “mean” products configuration across all individuals and which gives important insight into the overall perception of the products (Tomic et al., 2015).
All words and terms described by the participants in the descriptive stage were qualitatively analyzed. The terms that characterized each stimulus were grouped semantically, and the mention frequency was determined by counting the number of times the term was used to describe the stimulus. Only the terms mentioned by at least 5% of participants were used as supplementary variables in the MFA (Pereira et al., 2016).
3. RESULTS
3.1 Focus Group
The key issues raised in both focus groups were: knowledge and opinion about the products, perception of sensory quality, consumption of fermented dairy products, perceived benefits and appeals, and the opinion and information available for differentiating the products.
Theme 1: Knowledge about the products
Approximately 45% of consumers in the focus groups were unaware of the difference between the fermented dairy products under study, especially in relation to the fermented milk beverage.
“I did not even know there was such a difference. For me, all are yogurt and the differences were in accordance with the brands (woman, 46 years old, interview 2)”.
“I know fermented milk because I consume Yakult®, but I think I do not know fermented milk beverages. I may have read on the package, but with no association with a different product "(man, 33 years old, interview 2).
“People believe fermented milk beverage is low-cost yogurt, thinner "(woman, 26 years old, interview 1).
When the main technical differences between the products were explained, the consumers’ opinion about whey-based products was investigated. For those who have already known the product, the addition of whey in the formulation exerted little influence on the purchase intention, but some nutritional and sensory distinctions were reported.
“For me, whey is just a component of the formulation. Nevertheless, I have a preference for yogurt. It is thicker than fermented milk beverage "(woman, 29, interview 1).
"Depends on the amount added (whey). I consume fermented milk beverages, mainly due to the wide variety of products, but I think they are less nutritious than yogurt. Less protein, less calcium "(man, 27, interview 1).
"They have whey protein (milk), right? I think it is good to consume these products. I see no problems "(woman, 42 years old, interview 2).
"Fermented milk beverage has poorer quality than yogurt, especially with respect to its sensory characteristics." (woman, 31, interview 1).
Participants who were unaware of whey-based products had neutral opinions, despite the emotional rejection and negative connotations to the whey-based product.
“I have my doubts (about the quality of the product). It should not be as healthy as yogurt; otherwise it would be better explained in the product disclosure. I never noticed, but feel cheated to buy milk beverage instead of the yogurt. They are all very similar. This should be more explicit "(woman, 40 years old, interview 2).
"I will pay more attention to packaging. The product may not harm but may be less healthy than yogurt "(woman, 58 years old, interview 2).
"Nothing is changed for me. I will continue eating the product, but knowing the formulation "(man, 23, interview 2).
Theme 2: Perception of sensory quality of the products
Participants who knew the differences were asked about the perception of quality of the different fermented dairy products, and for those who did not know it before, it was asked the expected quality of them. Most of the participants pointed out creaminess, aroma, and sharp taste as main characteristics of the products. The fermented milk beverage was seen as a less flavored and more liquid than yogurt. In contrast, the fermented milk was considered as similar to milk, but with higher acidity. However, the vast majority believed that manufacturers tend to approximate the organoleptic characteristics so that consumers associate other products with yogurt.
“I did not realize the difference until now ... Some are more liquid, others more consistent, and I thought the differences were associated with the brand. From now on, I will pay more attention. I will give preference to yogurt "(man, 33 years old, interview 2).
"The fermented milk beverage is like low-fat yogurt, little watery, tasteless ... Poor. Fermented milk has the same texture than milk but is sourer, which depends on the flavoring "(man, 27, interview 1).
"The fermented milk beverages and fermented milk are more watery. The other (yogurt) is creamier and tastier (woman, 29 years old, interview 1).
"The fermented milk beverages have bitter taste and are very liquid. Fermented milks are generally much more acidic, while yogurts are creamy, more flavored, and sweet" (woman, 28 years old, interview 2).
“Today I believe that the differences (between the products) are due to the brands. The industries formulate products according to the consumer desire. The fermented milk beverage may be more liquid, but it contains gum and has similar texture to yogurt, thus consumer thinks he is consuming yogurt "(woman, 29 years old, interview 1).
Theme 3: Consumption of fermented dairy products
In another key topic, questions were raised about the consumption of fermented dairy products. Consumer’s responses evidenced some consumption patterns. Yogurt consumption is mainly associated with breakfast, morning consumption, and weight loss, being considered a proper meal for some participants.
“I always eat my yogurt in the morning, pure or together with some fruit. Sometimes I replace dinner by yogurt. It helps dieting "(woman, 29 years old, interview 1).
"I think that suits with breakfast. It comes from milk, recalling milk "(man, 42, interview 2).
"I consider a healthy and suitable product for breakfast. It's better than eating bread, cake ... It's less caloric (woman, 58 years old, interview 2).
For those who were unaware of the difference between fermented milk beverages, yogurts and fermented milk, consumption was associated to yogurt. For those who had prior knowledge, milk beverage is seen as a more versatile product, consumed due to high variability, various flavors and brands, as well as convenience and more affordable price when compared to other fermented dairy products.
“I consume fermented milk beverage due to its various flavors. We can find strawberry, vanilla, and even jabuticaba flavored beverages in the market, among others. As they are more liquid, are more practical to consume "(man, 27, interview 1).
"Most people consume because they associate it with yogurt. It is a low-cost product, and thus more accessible to people "(Woman, 29 years, interview 2).
Fermented milk was raised as a familiar product to all participants, but for the vast majority, it was associated with specific brands, with well-defined flavor, aimed at children, with versions for other age groups. Emotional connotations as nostalgia and concern were reported.
"Fermented milk always reminds me of Yakult® and living lactobacilli. It is a delight but was afraid to consume more than one and not feel well "(man, 27, interview 1).
"Fermented milk reminds me of my childhood. I have the impression that it is focused at children. In my memory there is only Yakult®, Chamyto® "(Woman, 29, interview 2).
"This brand is popular with children, and industry is trying to reach the adult public. Some time ago, Yakult 40® emerged on the market (woman, 58 years old, interview 2.
"Everyone associates fermented milk to Yakult®, despite Activia® and other brands, but we all think it is yogurt. Just look at the packaging! "(woman, 29 years old, interview 1).
Although the present study deals with liquid products, during the discussion about consumption of yogurt, in both groups, there were relevant comments on the category of Greek yogurt, and most respondents elicited their preference for Greek yogurt. This product showed to be popular due to its high creaminess, great variety of flavors, besides not being associated to morning consumption.
"Greek is the best of all. It is more creamy and consistent. Sometimes I eat it as afternoon snack "(woman, 40, interview 2).
"There is a wide variety of Greek yogurt, with various flavors and fruit pieces. For me, it serves as a healthy dessert "(man, 27, interview 1).
"Greek yogurt is a different product. It is creamy, full-bodied, and tastier and we can eat with a spoon, and I always associate with a dessert, a snack "(woman, 46 years old, interview 2).
Theme 4: Benefits and appeals of fermented dairy products
All respondents believed in the benefits and appeals assigned to the products, including the light products, zero fat, and probiotic one. Nevertheless, they believed that the products have specific target groups, and marketing does not encourage consumption in other niche market.
"Look at the example of Activia® (probiotic fermented milk); advertising is directed to women seeking to reduce bloating and to regulate intestinal transit. It seems that is a product aimed only at women but it is yogurt, with similar benefits for men "(man, 27, interview 1).
"Most of the fermented milk is directed to children. The slogan of living
lactobacilli help the body is anchored in people's minds even after they grow up"
(Woman, 26, interview 1).
"I prefer the full-fat product, it is more tasty, but I can change it for a similar light product with less calories if I'm in weight loss process" (woman, 46 years old, interview 2).
Theme 5: Information about product differentiation
Among the participants in the Focus Groups, about 85% believed that despite information is on the labels, it is not clear, with visible spaces that allow products’ differentiation. Some respondents also reported that consumers are not used to read the entire label. Some respondents reported that besides the lack of information, markets put their products on the shelves in order to confuse consumers.
"It may be written on the package which is what, but as packages are similar, confusion can happen, thus consumer can buy a product thinking it was the other" (man, 26 years old, interview 1).
"You arrive at the market and the products are all mixed on the shelves. The products are separated by brands rather than types, which confuses consumers even more "(woman, 29, interview 1).
"Information is in the label, but consumers trust the brand. He thinks, for example, that NESTLÉ® brand produces yogurts, then he takes the NESTLÉ® package and goes away, when in fact he bought fermented milk beverage or fermented milk "(man, 46 years old, interview 2).
"Consumers pay attention only to the expiration date and caloric values" (man, 28 years old, interview 2).
As reported by the respondents, yogurt is purchased and consumed mainly by presenting health benefits, besides being a source of protein and other nutrients. Fermented milk is seen as a good product but with little variety of flavors. In contrast, most participants believe that the sales of fermented milk beverages are driven by the wide variety of products and consumer misinformation.
"I consume yogurt because it is a healthy product, source of calcium, protein and it is easy to digest. I do not know if other products have similar benefits"(woman, 58 years old, interview 2).
"I know that fermented milk has living lactobacilli, but I unaware about dairy beverages" (Woman, 29, interview 2).
"I think people just buy fermented milk beverage due to different flavors, and they think they are buying yogurts. I doubt if consumers would buy even though it was another product "(man, 27, interview 1).
3.2 Word Association Task (WA)
The level of familiarity of the participants with the different types of fermented dairy products was assessed before the WA and PM performance and is presented in Table 2. According to the findings, yogurt showed the highest average (4.00) among the products under study, statistically different from the others, demonstrating the high degree of
familiarity of the participants with this product. In contrast, the fermented milk and fermented milk beverage exhibited lower mean values (3.33 and 2.88, respectively), with no significant differences between them, demonstrating the most superficial relationship between these products and participants.
Table 2. Mean values of participants’ familiarity level about the three different fermented
dairy products in both Word Association Task and Projective Mapping.
Familiarity
Dairy Product Word Association Projective Mapping
Yogurt 4.00a 3.86a
Fermented Milk 3.33b 2.86b
Fermented Milk Beverage 2.88b 2.81b
*Means with within a column with different superscript letters differ statistically according to Tukey’s test (p<0.05).
In the WA findings, 1394 terms were generated and considered in the development of the methodology. Fifteen categories were identified using the associations obtained for all stimuli investigated, and all terms were ranked within these categories. The associations were highly significant to the stimuli, suggesting that the information significantly affect consumers’ perception about the different fermented milk products (X2 =
483.76, p < 0.001). In addition, the application of cell chi-square test in the contingency table of WA also permitted to identify the category more or less assessed for each type of stimulus. Table 3 shows the fifteen categories and examples of terms and their respective frequencies.
The full-fat yogurt (WYOG) was positively characterized by the categories "Sensory Attributes", "Positive Feelings" and "Composition", with fewer citations for the categories "Negative Feelings" and "Detriments ". The stimulus to the low-fat yogurt (SKYOG) was mostly classified by having high frequency of mention for the categories "Related to Diet" and "Detriments". The stimulus PYOG (probiotic yogurt) was perceived by consumers by having more terms in the classes "Positive Feelings," "Benefits" and less mainly related to the categories "Sensory Defects" and "Detriments".
Table 3.Contingency table showing main categories and example of associations elicited by consumers to WYOG (full fat yogurt), SKYOG (low-fat yogurt), SPYOG (probiotic yogurt), WFM (full fat fermented milk), SKFM (low-fat fermented milk), PFM (probiotic fermented milk), FMB (fermented milk beverage), and PFMB (probiotic fermented milk beverage). Number of citations per stimuli and results of the chi square per cell are also presented.
Category Examples WYOG SKYOG PYOG FMB PFMB WFM SKFM PFM
Sensory Attributes consistent, creamy, tasty 82(+) 32 19(-) 20(-) 14(-) 31 21 15(-)
Positive Feelings cheerful, smart, protected,
energized 63
(+) 21 38(+) 7(-) 18 19 13(-) 31
Benefits
good for immunity, nutritious, it lowers cholesterol
15(-) 31 38(+) 5(-) 26 13(-) 23 37(+)
Sensory Defects líquid, bitter, it is not tasty 3(-) 20 6(-) 30(+) 15 6(-) 21(+) 5(-)
Technological Process
reuse, pasteurization,
fermentation, processed 23 4
(-) 11 22(+) 12 9 5(-) 17
Composition calcium, fat, lactose,
protein 35
(+) 7(-) 2(-) 14 9 21(+) 8 7
Related To Diet diet, lose weight, light,
calories 23 21
(+) 4(-) 2(-) 6 8 17(+) 5
Marketing novelty, quality, targeted
to children and women 13 7 13 7 6 17
(+) 6 13
Comsumption breakfast, I like it cold,
snack, meal 17 7 5 8 8 9 8 5
Detriments less nutritious, bland, less
healthy 2
(-) 12(+) 2(-) 22(+) 1(-) 4 7 2(-)
Neutral Feeling curious, doubt, skeptical 1(-) 4 8 8 7 3 2 8
Costs more expensive, cheaper,
price 2
(-) 0(-) 6 14(+) 2 5 1(-) 5
Negative Feelings discouraged, deceived,
suspicious 0
(-) 1(-) 3 15(+) 7(+) 1 2 2
Related to Dairy Product
imitation of yogurt,
cheese, fermented milk 7 0
(-) 1(-) 11(+) 4 4 1 2
Life Style fitness, balanced meal,
gym 10 5 5 0
(-) 0(-) 1 3 2
(+) or (−) indicate that the observed value is higher or lower than the expected theoretical value. p<0.05; effect of the Chi-square per cell.
Among the stimuli related to fermented dairy beverages, the sample FMB (fermented milk beverage) showed high frequency of mention for the categories "Sensory Defects", "Technological Process", "Detriments", "Costs", "Negative Feelings" and "Related to Dairy Products", and low frequency for the categories "Sensory Attributes", "Positive Feelings" and "Benefits". As for the functional product of this category (probiotic fermented milk beverage - PFMB), a slightly different profile was identified, with more citations only for the "Negative Feelings" and low frequency for "Sensory Attributes" and "Detriments".
The stimulus for full-fat fermented milk (WFM) was positively characterized by the categories "Composition" and "Marketing", and negatively by "Benefits" and "Sensory Defects". For the low-fat fermented milk sample (SKFM), high citations were observed for "Sensory Defects" and "Related to Diet", with low frequencies for "Positive Feelings" and "Technological Process". Finally, the probiotic fermented milk (PFM) received more citations for the categories "Benefits" and fewer citations for the categories "Sensory Attributes", "Sensory Defects" and "Detriments".
In order to view the profile and identify the correlations between stimuli and categories based on frequency of mention raised by consumers, Correspondence Analysis (CA) was applied and the results are shown in Figure 2.
WYOG SKYOG PYOG FMB PFMB WFM SKFM PFM Sensory Attributes Positive Feelings Benefits Sensory Defects Technological Process Composition Related to Diet Marketing Comsumption Detriments Neutral Feeling Costs Negative Feelings Related to Dairy Product Life Style -0,8 -0,3 0,2 0,7 -1 -0,5 0 0,5 1 F2 (26,34 %) F1 (45,31 %) Symmetrical graphic (axes F1 e F2: 71,65 %)
Figure 2. Correspondence Analysis on contingency table crossing the different stimuli of
fermented dairy products and main categories cited by consumers. Triangles represent the different samples (stimuli): WYOG (full fat yogurt), SKYOG (low-fat yogurt), SPYOG (probiotic yogurt), WFM (full fat fermented milk), SKFM (low-fat fermented milk), PFM (probiotic fermented milk), FMB (fermented milk beverage), and PFMB (probiotic fermented milk beverage), and circles represent the projection of the categories used.
The first two dimensions of CA accounted for 71.65% of the total experimental variance. According to WA, the first dimension of CA was responsible for positively
characterize the stimuli through the categories "Negative feelings" and "Detriments", and negatively by "Life Style" and "Positive Feelings." The second dimension was positively correlated with the categories "Composition" "Sensory Attributes" and negatively characterized by "Benefits" and "Neutral Feelings".
In this sense, the sample FMB was characterized mainly by the categories "Negative Feelings", "Detriments" and "Related to Dairy Products." The stimuli related to probiotic samples (PYOG and PFM) were perceived similarly, being characterized by the category "Benefits" and "Neutral feelings". The stimulus PFMB, characterized by the categories "Marketing", "Sensory Defects" and "Neutral Feelings" was between the conventional product (FMB) and the low-fat samples (SKYOG and SKFM). The low-fat samples in turn were perceived by consumers through the categories "Marketing", "Positive Feelings," "Technological Process", "Related to Diet" and "Consumption".
The stimulus WYOG, containing the information "full-fat yogurt", was characterized by presenting relevant terms through the categories "Sensory Attributes" and "Composition", while WFM was highly correlated with the attributes "Consumption", "Sensory Attributes" and "Related to Diet ".
3.3 Projective Mapping
According to Table 2, yogurt had the highest average (3.86) in the measurement of level of familiarity, with significant differences from the other products. In contrast, no significant differences were observed between fermented milk (2.86) and fermented dairy beverage (2.81). According to the consumers’ description, it was possible to determine 10 different main categories related to fermented dairy products. The most cited categories were "Sensory Attributes", "Positive Feelings", "Sensory Defects" and "Related to Diet", very similar to the results of Word Association Task, although the PM technique has been able to raise fewer categories between stimuli when compared with WA.
According to Figure 3, the first two dimensions of the MFA accounted for approximately 77.8% of the differences between the different stimuli. The first dimension was positively characterized mainly by the categories "Positive Feelings," "Benefits" and "Sensory Attributes", and negatively characterized by the categories "Negative Feelings", "Detriments"
and "Sensory Defects". The second dimension was highly correlated with the category "Related to Diet".
The results show that consumers have grouped stimuli according to the category and added appeal. The full-fat samples, WYOG and WFM were characterized similarly by the categories "Composition", "Consumption", "Sensory Attributes" and "Positive Feelings." The probiotic samples, PYOG and PFM, were characterized by the “Marketing” and “Benefits”.
WYOG SKYOG PYOG FMB PFMB WFM SKFM PFM Sensory Atributes Sensory Defects Positive Feelings Negative Feelings Composition Related to Diet Comsumption Benefits Detriments Marketing -1,5 -1 -0,5 0 0,5 1 1,5 2 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 F2 (17,04 %) F1 (60,75 %) Biplot (axes F1 e F2: 77,79 %)
Figure 3. Results of the Projective Mapping task in the first and second dimensions of the
Multiple Factor Analysis (MFA): triangles represent the different samples (stimuli), where WYOG (full fat yogurt), SKYOG (low-fat yogurt), SPYOG (probiotic yogurt), WFM (full fat fermented milk), SKFM (low-fat fermented milk), PFM (probiotic fermented milk), FMB (fermented milk beverage), and PFMB (probiotic fermented milk beverage), and circles represent the projection of the categories used in the description phase.
The low-fat samples SKYOG and SKFM were similarly grouped and characterized by the categories "Related to Diet” and "Sensory Defects". Among the stimuli related to fermented milk beverage, the more related categories were "Negative feelings" and "Detriments".
4. DISCUSSION
Under our knowledge, this study is the first to investigate more deeply the consumers’ perception of different categories of fermented dairy products through exploratory research with qualitative nature, such as Word Association, Focus Groups and Projective Mapping.
As observed, the intrinsic characteristics expected for the different products are responsible for much of the indications raised by participants in all tests. The category "Sensory attributes" correlated to terms such as strawberry, sour, fermented flavor, creamy, and consistent was the most frequently mentioned category in both Word Association Task (WA) and Projective Mapping (PM), demonstrating the importance of this dimension for differentiation and choice of different categories of fermented dairy products. Still regarding this subject, the category "Sensory Defects" fourth most cited in the WA, and second most cited in the PM, was related mainly to the attributes liquid, tasteless, and bitter. Endorsed by the responses from the Focus Groups, it is noted that some of the main expected differences referred to the quality and sensory characteristics of the products.
Our results have been aligned with those in previous studies on these products. According to Janiaski et al. (2016), who studied the technological optimization of yogurts and fermented milk beverages, the sensory properties play a key role to the marketing of fermented dairy products among consumers. Flavor attributes influenced by organic acids and peptides derived from fermentation and other flavor compounds are relevant to the choice of these products, for example (Hekmat & Reid 2006; Soukoulis et al., 2007).
However, texture attributes play an important and decisive role on the final quality of dairy products (Ares et al., 2008; Castro et al., 2013a; Morell et al., 2015). According to Soukoulis et al. (2010) attributes such as creaminess, body, and viscosity have great importance for the acceptability of semi-solid dairy products. As the main difference between these products is related to the addition of whey and use of different lactic acid cultures, with direct influence on viscosity (Castro et al., 2013b; Mani-Lopez et al., 2014), Janiasky and colleagues (2016) have reported there is an imminent need for optimization of the formulation, especially concerning the texture attributes for improving acceptance of these products.
