How reliable are the consumers? Comparison of sensory profiles from - PowerPoint PPT Presentation

How reliable are the consumers? Comparison of sensory profiles from consumers and experts from consumers and experts WORCH Thierry (1) LÊ Sébastien (2) LÊ Sébastien ( ) PUNTER Pieter (1) (1) OPP Product Research mailto: thierry@opp.nl (2) A (2) AgroCampus Ouest C O t Project 8013 Senior project manager Pieter Punter July 2008 Project manager Thierry Worch

introduction • in the sensory theory: • experts panels are used for the products’ description p p p p • consumers should only be used for the hedonic task • they lack two essentials qualities for profiling (consensus and reproducibility) • there are strong halo effects (Earthy, MacFie & Hedderley, there are strong halo effects (Earthy, MacFie & Hedderley, 1997) • in the sensory practice: • consumers are sometimes used for both tasks • it has been proven that consumers’ description show the • it has been proven that consumers description show the required qualities (consensus and reproducibility) (Husson, Le Dien, Pagès, 2001) 3 8013

4 How reliable are the consumers? problematic 8013

presentation of the studies • products : • twelve luxurious women perfumes twelve luxurious women perfumes (Gazano, Ballay, Eladan & Sieffermann, 2005) A Angel l L’Instant L’I t t (Eau de Parfum) (Eau de Parfum) Cinéma J’Adore (Eau de Parfum) (Eau de Toilette) Pleasures J’Adore (Eau de Parfum) (Eau de Parfum) (Eau de Parfum) (Eau de Parfum) Aromatics Elixir Pure Poison (Eau de Parfum) (Eau de Parfum) Lolita Lempicka Shalimar (Eau de Parfum) (Eau de Toilette) Chanel N°5 Chanel N 5 Coco Mademoiselle Coco Mademoiselle (Eau de Parfum) (Eau de Parfum) 5 8013

presentation of the studies • expert panel (Agrocampus Rennes) • twelve persons (11 students and 1 teacher) from the Chantal Le Cozic school (esthetics and cosmetic school) • focus group per group of six, with two animators • generation of a list of twelve attributes • generation of a list of twelve attributes • “ Vanille”, “Notes Florales”, “Agrume”, “Boisé”, “Vert”, “Epicé”, “Capiteux”, “Fruité”, “Fraîcheur Marine”, “Gourmand”, “Oriental”, “Enveloppant” • training session for the most difficult ones • the twelve products were tested two times in two one-hour sessions 6 8013

presentation of the studies • consumer panel (OP&P Product Research, Utrecht) • 103 naïve Dutch consumers living in the Utrecht area • the same twelve perfumes were rated on 21 attributes • the same twelve perfumes were rated on 21 attributes • “odour intensity”, “freshness”, “jasmine”, “rose”, “camomile”, “fresh lemon”, “vanilla”, “mandarin/orange”, “anis”, “sweet fruit/melon”, “honey”, “caramel”, “spicy” “woody” “leather” “nutty/almond” “musk” “animal” “earthy” “incense” spicy , woody , leather , nutty/almond , musk , animal , earthy , incense , “green” • two products (Shalimar and Pure Poison) were duplicated • the fourteen (12+2) products were tasted in two one-hour sessions (seven products in each session, presentation order was balanced) 7 8013

presentation route map • the consumer and expert data are compared in three different ways 1.Univariate analysis • analyses of variance • correlations 2 Multivariate comparison 2.Multivariate comparison • construction of the two products’ spaces (PCA) • comparison of the products’ spaces through GPA and MFA comparison of the products spaces through GPA and MFA 3.Confidence ellipses • graphical confidence intervals around the products averaged over the two panels • graphical confidence intervals around the products defined graphical confidence intervals around the products defined by the different panels 8 8013

Performance of the two panels (univariate analysis) 9 8013

performance of the panels • usually, the expert panels should have many qualities: • discrimination: panelists should be able to detect and describe the differences existing between the products • reproducibility: panelists should describe the products in the same way, when they are repeated same way, when they are repeated • agreement: panelists should give the same description of the products as the rest of the panel f • it can be measured with the correlations (usually, one panelist is compared to the mean over the rest of the pa e s s co pa ed o e ea o e e es o e panel) 10 8013

expert panel • panel performance • discriminate on 11 out of 12 attributes (“Agrume”, pvalue=0.08) • reproducible for 11 out of 12 attributes (“Notes Florales”) • panellist performance (discrimination, reproducibility) panellist performance (discrimination reproducibility) • panellists 1, 3 and 12 are very good panellists 1, 3 and 12 are very good • panellists 8, 9 and 10 are not good in discrimination (discriminate the products on less than 6 out of 12 attributes) • panellist 9 is also not good in reproducibility (reproducible on lli 9 i l d i d ibili ( d ibl only 3 out of 12 attributes. “Notes Florales”, “Agrume” and “Enveloppant”) 11 8013

expert panel (correlations) • distribution of the correlations (correlation between expert i and the mean over the (n-1) others) ( ) ) 12 8013

consumer panel • discrimination (on the twelve original products) • the consumers discriminate the products on all attributes except “camomile” (pvalue = 0.62) • NB : the consumers discriminate on “Citrus” (pvalue < 0.001) • reproducibility (on the two duplicated products only) • consumers are reproducible on all attributes except one (“woody”) 13 8013

14 consumer panel (reproducibility) Shalimar 2 8013 Shalimar

consumer panel (correlations) • distribution of the correlations (correlation between a consumer i and the mean over the (n-1) others) ( ) ) 15 8013

conclusions on the panel performance • expert panel • discriminates between the products discriminates between the products • are reproducible • high correlations • consumer panel consumer panel • discriminates between the products • shows reproducibility’s qualities shows reproducibility s qualities • lower but still positive correlations (consumers are untrained) Both panels show the same qualities Both panels show the same qualities 16 8013

17 (multivariate analysis) Products’ spaces 8013

methodology • products’ spaces • the products profiles (averaged over the panellists or consumers) the products profiles (averaged over the panellists or consumers) are computed. • Principal Components Analysis is then run on these product x attribute matrices attribute matrices • comparison of the two products’ spaces (expert and consumer) is a comparison of the two products spaces (expert and consumer) is a “multi-table problem” • comparison through the Procrustean analysis • comparison through Multiple Factor Analysis (MFA) ( ) • comparison through the confidence ellipses technique 18 8013

expert panel g p 3,5 3,0 AromaticsElixir AromaticsElixir 2 5 2,5 Shalimar 2,0 1,5 Pleasures Chaneln5 1,0 1 %) JAdore EP _ nsion 2 (21.87 % 0,5 PurePoison JAdore_ET 0,0 CocoMelle Boisé -0,5 Epicé -1,0 LInstant Dimen Notes.florales Oriental -1,5 Vert Cinema 2 (21.87 %) Capiteux Angel Agrume -2,0 -2,5 Fraicheur.marine 0 0 -3,0 Dimension LolitaLempicka -3,5 Enveloppant -4,0 Fruité -4,5 -4 -3 -2 -1 0 1 2 3 4 Dimension 1 (64.22 %) Vanille Gourmand -1 -1 0 1 Dimension 1 (64.22 %) 19 8013

consumer panel 6,0 5,5 5,0 4,5 4,0 LolitaLempicka 3,5 g 3,0 2,5 Angel Cinema 1 2,0 LInstant vanilla %) 1,5 1 5 nsion 2 (17.97 % honey 1,0 JAdore_EP 0,5 caramel 0,0 anis camomille JAdore_ET -0,5 CocoMelle Pleasures PurePoison -1,0 citrus Dimen Chaneln5 -1,5 Shalimar nutty -2,0 n 2 (17.97 %) sweet_fruit -2,5 -3,0 freshness -3,5 green 0 -4,0 animal animal jasmin jasmin Dimension AromaticsElixir musk rose -4,5 incense leather -5,0 woody -5,5 fresh_lemon earthy -6,0 -6,5 -7,0 7 0 i t intensity it spicy i -5 -2.5 0 2.5 5 7.5 Dimension 1 (68.29 %) -1 1 -1 0 1 Dimension 1 (68.29 %) 20 8013

Multivariate comparison of the two panels (GPA and MFA) 21 8013

expert vs consumer: Procrustes analysis GPA consensus space 0.4 (coefficient of similarity: 0.93) (coefficient of similarity: 0.93) 0.3 LolitaLempicka 0.2 A Angel l 0 Cinema LInstant 0.1 m 2 Dim 0.0 CocoMelle JAdore_ET JAdore_EP PurePoison Pleasures -0.1 Shalimar Chaneln5 AromaticsElixir -0.2 - -0.3 -0.2 0 2 0 0 0.0 0.2 0 2 0 4 0.4 Dim 1 22 8013

expert vs consumer: Multiple Factor Analysis MFA partial points’ experts consommateurs representation 2 (RV coefficient: 0.87) LolitaLempicka Angel Angel 1 Cinema LInstant 9.35 %) JAdore_EP CocoMelle Dim 2 (1 JAdore_ET 0 PurePoison Pleasures Chaneln5 Shalimar -1 AromaticsElixir -2 -2 -2 -1 -1 0 0 1 1 2 2 3 3 Dim 1 (64.06 %) I di id l f t 23 8013