WINETECH Technical Yearbook 2020

Experiment 3

4

4

4

4

M_3

M_3

CS_3

CS_3

M_1_Dupl

M_1_Dupl

PT_3

PT_3

SH_1

SH_1 CS_2

4MMP

3MH

3

3

M_2

M_2

x

CS_2

2

CS_1b

2

CS_1b

PT_2

CS_1a_Dup

PT_2

PT_2 M_3

CS_1a_Dup

2

M_3

2

x OR

PT_1

PT_2

M_1

PT_1

M_1

M_2

M_2

CS_1a

CS_1a

4MMP

3MHA

1

1

PT_1

PT_1

SH_2

0

SH_2

0

SH_3

SH_3

CS_1b

CS_2

M_1_Dupl

CS_1b

CS_2

M_1_Dupl

0

Thiol

additions Wine matrices CS1a CS1b SH1 SH2

0

PT_3

PT_3

M_1

M_1

-2

-1

-2

-1

CS_3

CS_1a

CS_3

CS_1a

-2

-2

Dim2(12.1%)

Dim2(12.4%)

CS_1a_Dup

Dim2(12.1%)

Dim2(12.4%)

CS_1a_Dup

-4

-4

-3

-3

M1 CS2 CS3 M2 M3

-4

SH_3

-4

SH_1

SH_3

-6

SH_1

-6

SH_2

2a

2b

-5

SH_2

2a

2b

-5

-8

-6

-8

-6

-6

-4

-2

0

2

4

6

-6

-5

-4

-3

-2

-1

0

1

2

3

4

-6

-4

-2

0

2

4

6

-6

-5

-4

-3

-2

-1

0

1

2

3

4

Dim1(18.3%)

Dim1(14.1%)

Dim1(18.3%)

Dim1(14.1%)

PT1 SH3 PT2 PT3

3MH x 4MMP

3MHA x 4MMP

3MH x 4MMP

3MHA x 4MMP

FIGURE 1. Layout of Experiment 3.

FIGURE 2. Multifactorial analysis (MFA) maps for the two interactions studied. 1, 2 and 3 – three different wine bases, a and b – two CS samples independently processed, Dup – blind duplicate in the sensory test.

SUMMARY We discuss the results of Experiment 3 in which we assessed the importance of thiols interaction (4MMP x 3MH and 4MMP x 3MHA) in different wine matrices. From the study, it is clear that results cannot be extrapolated from one cultivar to another and the important role the matrix plays in the perception of wine aroma is confirmed.

important role the matrix plays in the perception of wine aromas. It also laid the foundation for investigating pairwise interaction of thiols in five different cultivars. Finally, in this issue (Experiment 3) we highlighted the importance of studies including various matrices. Experiments carried out in model wine are necessary for fundamental research but, to better understand the complex role of wine as a system, it is essential to incorporate different scenarios.

In the following issue (Part 2 – Experiment 1) we discovered that when thiols are present in red wine, the aroma attributes that come to mind are very different from the ones for white wine. Instead of ‘guava’, ‘grapefruit’ or ‘granadilla’, we get ‘caramel’, ‘savoury’ and other spicy notes, among others. In addition, the unmistakable role of the matrix became evident. With Experiment 1, we concluded that it is difficult to ascribe specific attributes to one of the three thiols tested. Exception is 4MMP for which the association with

‘blackcurrant’ has been confirmed as for the case of its presence in white wines. On the contrary, 3MH and 3MHA were associated with the presence of ‘savoury/ soy’ aromas. Part 3 (Experiment 2) elucidated the impact of thiols in combination with each other in one base wine. It demonstrated that, when looking at single compounds, the perception of the attributes is non- linear, especially when a second thiol is introduced. Synergistic and masking effects are noted and those results confirmed the

For more information, contact Valeria Panzeri

at valeria.panzeri@icloud.com or Astrid Buica at abuica@sun.ac.za.

WINETECH TECHNICAL YEARBOOK 2020 92

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