wac5bis by Bill Nanson

Oxidized Burgundy Chardonnay wines: sensory space boundaries, and identification of volatile target compounds.

Marie-Claude Naudota, Jean-Baptiste Alincb, Odile Meurguesb, Jean-Philippe Gervaisb, Julien Jaffréa, Yves Le Fura A UMR1129

Flaveur, Vision et Comportement du consommateur, ENESAD, INRA, et Université de Bourgogne, 17 rue de Sully, BP 86510, F-21065 Dijon Cedex, France Pôle Technique et Qualité du B.I.V.B. C.I.T.V.B. 6, rue du 16ème chasseur, F-21200 Beaune, France

Purpose p : new insights g in terms of boundaries and description p p provided by y sensory y space p analysis. y Eight g selected wines corresponding to the contrasting sensory subsets were analyzed by GC-O and GC-MS to identify and quantify the volatile compounds related to the aroma produced by oxidative degradation.

Sensory space of oxidized wine twenty-two 2000-2004 vintage wines without wood contact two pre-established categories: 11 wines declared to be oxidized (OX 01 to OX 11) 11 wines declared to be non-oxidized (SD 12 to SD 22) 28 panelists two tasks: categorization and description

Categorization: judgments were scored as “oxidized wine – sure”= -2,

“oxidized wine – not sure”= -1, “non-oxidized wine – sure”= 2 and “non-oxidized wine – not sure”= 1. Two-way ANOVA and Newmann-Keuls test (α = 5%). . distribution along g an oxidation g gradient from the most oxidized wine (OX 07: mean score =-1.18) to the wine consensually regarded as non-oxidized (SD 14: mean score=1.18) (figure 1).

Description: Correspondence Analysis (figure 2)

was performed using the 34 (out of 49) descriptors that had been selected by more than 4 judges for one wine at least, and 21 wines (OX 11 was eliminated by a previous C Correspondence d A Analysis l i ) 1,2

1 SD 17 Mean score

-1,18

****

OX 01

-0,93

****

OX 03

-0,89

****

OX 08

-0,79

****

OX 02

-0,75

****

OX 11

-0,32

****

OX 05

-0,21

****

SD 15

0,29

****

SD 19

0,36

****

OX 09

0,36

****

SD 16

0,39

****

SD 18

0,46

****

OX 10

0,54

****

SD 20

0,57

****

SD 22

0,61

****

OX 06

0,64

****

OX 04

0,82

****

SD 21

1,00

****

SD 13

1,04

****

SD 17

1,07

****

SD 12

1,14

****

SD 14

1,18

****

Oxidized wines Intermediate wines "neither oxidized nor non-oxidized"

Non-oxidized Non oxidized wines

The greater dispersion seen for the 10 wines considered as oxidized reflects a less consensual concept than for the other 11 wines

ether

glue

gouache SD 12 OX 02 SD 20 cider moldy mineral herbaceous fruit stone drug SD 14 1 2 SD 18 SD 15 3 SD 19 flowery hay 4 apple OX 05 yellow fruit wax honey butter OX 07 SD 13 SD 22 1,1 rancid butter ripe fruit OX 06 rancid honey SD 21 spicy woody caramel OX 01 pear OX 04 prune SD 16 OX 08 t t water t vanilla toasted stagnant madeira walnut quince OX 03

-1,1

The horizontal axis clearly separated terms denoting defects in the positive part and, in opposition, those denoting absence of defect.

Four of the five wines regarded as oxidized (OX 07, OX 01,OX 03, OX08) were grouped and mainly described by the terms Madeira, rancid honey, ripe fruit, walnut and prune, validating the oxidative features.

Figure 1: Newmann-Keuls test, distribution along the oxidation gradient

cork

OX 10 nail varnish

4 OX 09

Axe Vertical F 2

Wine OX 07

2 citrus fruit 3 exotic fruit

Axe -1,2 Horizontal F 1

Figure 2: projection of the various wines and sensory attributes in the plane of the first two axes, which accounted for 44.1% of total variance

Four oxidized wines (OX 07, OX 01, OX 08, OX 03), and four non-oxidized wines (SD14, SD 17, SD 13, SD 12) were selected for GC-O and GC-MS analysis

Physico-chimical investigations discriminative areas displayed by GC-O and/or revealed by comparing the total ion chromatograms (TIC) (figure 3) identification (GC-MS) quantitative data (GC-MS-SIM) expressed as the relative concentration Ai/Ais in the extract, where Ai is the area of the i-compound, and Ais the area of the internal standard (methyl heptanoate) Principal Component Analysis 6

C14+C15

C7 C8+N

Figure 3: TIC comparison. Liquid-liquid extraction with dichloromethane, GC-MS equipped with capillary columns DB1701. In blue, differences between top (OX07) and bottom (SD12)

28 volatile compounds were identified. Six areas of interest remained unidentified. Taken together, they were hypothesized as the cause of the oxidation features. Initial GC-MS-SIM assay of certain of these compounds (19 out of 28) seems to bear out this hypothesis. Principal component analysis (figure 4) revealed the existence of contrasting g composition p p patterns:. Oxidized wines had,, in almost all cases (except hex-2-en-1-ol), the highest levels of the target compounds.

OX 01

2 Principal component 2 : 17.09%

C1: 1,1-diethoxyethane; C2: ethyl-2-methylpropanoate; C3: 3-ethoxypropan-1-ol; C4: hex-2-en-1-ol; C5: 2-acetylfurane; C6: 3-methylthiopropanal (methional); C7: benzaldehyde; C8: 5-methylfurfural; C9: benzyl alcohol; C10: 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon); C11: 2-methoxy-4-(2propenyl)-phenol (eugenol); C12: 1-(4-hydroxy-3-methoxyphenyl)-ethanone (acetovanillone); C13: furfural; 1,0 C14: furfuryl alcohol; C14 C15: 3-methybutanoic acid; C16: g-butyrolactone; C17: diethyl-2-hydroxybutanedioate; C12 0,5 C18: 2-ethoxypropane; C11 C19: ethyl-2-hydroxy-3-methylbutanoate. Fact. 2 : 17,09%

C13

SD14 SD13 SD17

SD12 0

OX 03

OX 07

-1

-2

-3

OX 08 -4

-5

C15 C8 C10 C5

-6 -6

-4

-2 Principal component 0 1 : 55,00% 2

0,0 C16

C18 C1 C2 C19

-0,5

C13 C17

-1,0 -1,0

-0,5

0,0

Fact. 1 : 55,00% ,

0,5

1,0

Figure 4: Principal Component Analysis: representation of 19 target compounds and 8 wines in the plane of the first two principal components, which accounted for 72.1% of total variance

Conclusion: such a difference seems to indicate that the selected compounds determined a clear pattern of composition which could be linked to the sensory profile of the wine.

Wine active compounds International Conference – Beaune - France March 27th–29th 2008