3.2 Impact of optimised cork powder on wine chromatic characteristics and phenolic compounds

Application of optimised cork powder results in a decrease of the colour intensity, although being only significantly different from the control for the CKFI and CKFI75500. For the L\* and a\*, the same was observed (Table 4). These variations for the colour intensity are not due to a decrease in the concentration of monomeric anthocyanins that generally did not change by the use of all cork powders (Table 5). For the individual phenolic acids overall, their levels did not change significantly, or their decrease was significant but small, and these decreases occurred mainly for the CKFI75 at the two application doses (decreased for transcaftaric acid—5.6%; coutaric acid—5.9%; caffeic acid—20%; ferulic acid—12% and coumaric acid ethyl ester—19%) (Table 5). For catechin, there was no change in its levels for all cork powders applied. These results show that optimised cork powders, either with or without extractive removal, have a low impact on wine phenolic composition; nevertheless, the ethanol impregnated extractive free corks had a significant impact on wine colour intensity, suggesting that these corks influence wine polymeric pigments as no significant changes on monomeric anthocyanins were observed. The impact for cork powders on wine phenolic composition and colour intensity of wines was lower than that generally observed for activated carbons used at 100 g/hL [20].

#### 3.3 Impact of optimised cork powder on wine sensory attributes

To validate the impact of natural and extractive free ethanol impregnated cork powder samples on the headspace VP decrease and its effect on the sensory perception and quality of wines, CKNI, CKFI and CKFI75—treated wines at the two application doses (250 and 500 g/hL, CKFI75250 and CKFI75500, respectively) were subjected to sensory analysis by an expert panel. As expected, the presence of these VPs affect the aroma profile of spiked wine (TF) significantly and negatively (Table 6), by the increase of the phenolic attribute, decreasing the wine fruity and floral attributes significantly [20, 24, 55]. The panel consensus on each wine attribute was accessed through the percentage of variance explained by the first PCA [56] applied to the panel scores for each attribute. The variance explained by PC1 ranged from 45 to 87%, yielding the C-indexes presented in Table 6. Similar values have been reported for trained panels assessing different attributes and different products [20, 24, 62]. Colour intensity, floral, fruity, phenolic, acidity, balance and persistence wine attributes resulted in a consensus among judges (Table 6). For the colour hue, limpidity, oxidised (visual), vegetable, oxidised (aroma) and body, the judges attributed identical scores. There is no consensus on the other sensory wine attributes that could be due to the low difference of the attributes among samples or changes in motivation, sensitivity and psychological answer behaviour [57].

In accordance with the instrumental colour intensity, sensory colour intensity of the wines treated with ethanol impregnated extractive free cork powders was significantly lower than T0 and TF, with the increase in the application dose

Compounds

236

Ethyl acetate

3-Methylbutan-1-ol-acetate

2-Methyl-1-butanol

Ethyl hexanoate

Ethyl octanoate

Ethyl decanoate

Diethyl succinate

Phenylethyl

 acetate

2-Phenylethanol

4-Ethylguaiacol

Reduction SPME (%)

Octanoic acid 4-Ethylphenol Reduction SPME (%)

Decanoic Dodecanoic Total area-VPs Reduction (%)

Results are expressed in absolute area (105). Data are presented as

[63–65]. Values within a line followed by the same letter are not significantly different ANOVA and Tukey post-hoc test (<sup>p</sup> 0.05). n.d., not detected;

corks.

p < 0.05.

Table 3. Headspace

and ethanol extractive free cork after air removal and ethanol

(CKF75250

 and

CKFI75500).

 aroma profile of red wines before (VP-free T0 and VP-spiked with 750 μg/L of 4-EP and 150 μg/L of 4-EG, TF) and after treatment with natural cork and

impregnation

 (CKNI and CKFI) and cork powders with a particle size below 75 μm at two application

X

 s; ID, identification;

 std, standard; and RI, retention index [60–62], MW, molecular weight; LOD, limit of olfactory detection). Odour descriptor

std

std

 2136

 2156

 Waxy

 2129

 2196

 Rancid

1.0

6.1

 5.48 962.7

 28.0a

—

 —

31.9 uncontaminated

 (T0) spiked red wine (TF) and wines treated with

dichloromethane

 doses (250 and 500 g/hL)

36.7

40.4

69.1

958.7

 46.7a

652.9

 10.1cd

607.0

 32.1d

571.1

 68.3d

296.7

 71.1e

 0.36a

5.23

 0.59a

0.93

 0.15c

 0.90

 0.41c

0.90

 0.13c

n.d

 4.14

 0.45a

4.19

 0.43a

1.49

 0.17ab

2.53

 2.76ab

1.24

 0.62ab

n.d

std

std

 2084

 2142

 Phenolic

 2036

 2030

 Rancid

0.5

0.4

n.d.

 18.25

 1.23a

10.37

 0.31c

43.1

46.1

56.5

81.5

9.83

 0.89c

7.94

 2.19c

3.37

 1.35d

 17.87

 0.57a

17.62

 0.73a

6.00

 3.79cd

8.98

 0.97bc

7.19

 1.32cd

2.30

 1.20d

std

 2012

 1989

 Smoke

 std std

 2000

 1911

 Roses

 1809

 1833

 Flowery

 std std

std

std

std

 1683

 1698

 Light fruity

 7.5 0.25

14.0

0.15

n.d.

 16.62

 0.89a

9.21

 0.41c

44.6

45.6

50.6

77.8

9.05

 0.68c

8.00

 2.25c

3.70

 1.07d

 365.23

 19.85a

362.73

 31.57a

247.32

 7.78b

240.73

 15.31a 216.92

 39.38b

136.16

 60.27c

 31.16

 4.66a

30.16

 3.51a

22.82

 0.89b

20.54

 1.13b

14.80

 6.94c

8.49

 2.96c

 66.90

 1.14a

64.40

 3.94a

41.95

 1.74cd

41.22

 1.81d

39.72

 3.78d

23.56

 5.20e

 1648

 1646

 Fruity

 1441

 1429

 Fruity

 1229

 1262

 Green apple

 0.014 0.005

1.5

 78.55

 3.63a

78.95

 5.89a

67.12

 6.21ab

53.94

 7.51b

36.93

 23.29c

19.61

 2.20c

 164.67

 19.71a 167.17

 10.85a

104.94

 6.78b

90.56

 12.53b

75.94

 27.94b

43.14

 1.49c

Advances in Grape and Wine Biotechnology

 27.62

 16.17a

27.87

 15.68a

25.65

 0.67ab

22.45

 1.30ab

20.69

 4.13b

12.92

 2.43b

 1229

 1223

 Malty

 std

 1121

 1126

 Banana

ID RI calculated

—

725

 715

 Fruity

7.5

0.03

0.48

 112.02

 8.60a

109.52

 8.6a

77.47

 2.20c

71.24

 3.46c

76.13

 5.49c

50.10

 8.03d

 65.09

 15.64a

67.59

 19.86a

44.36

 3.22a

39.81

 4.81ab

35.30

 3.50ab

16.93

 3.95b

 23.97

 1.67a

23.29

 2.97a

14.32

 0.88b

14.13

 0.42b

14.70

 1.84b

8.53

 1.49c

 RI Odour descriptor

 ODT (mg/L)

 T0

TF

CKNI

CKFI

 CKFI75250

 CKFI75500



Samples

239

T CKNI

CKFI

CKFI75250

CKFI75500

 1.12 Gallic acid

> T

CKNI

CKFI

CKFI75250

CKFI75500

Values are presented as

Glc,

petunidin-3-glucoside,

petunidin-3-acetylglucoside,

coumaroylglucoside,

same letter are not significantly

p < 0.05.

Table 5. Monomeric

and ethanol

 anthocyanin

 and phenolic acid composition

impregnation

 (CKNI and CKFI) and cork powders with a particle size below 75 μm at two application

 of spiked red wines (TF) and after treatment with natural cork and

 Pet-3-CoGlc,

 different ANOVA and Tukey post-hoc test (<sup>p</sup> < 0.05).

 Peo-3-Glc,

 Peo-3-AcGlc,

petunidin-3-coumaroylglucoside,

peonidin-3-glucoside,

 Mal-3-Glc,

peonidin-3-acetylglucoside,

 Peo-3-CoGlc,

Mal-3-AcGlc,

malvidin-3-glucoside,

 Del-3-AcGlc, malvidin-3-acetylglucoside,

peonidin-3-coumaroylglucoside

 and

Del-3-CoGlc,

Mal-3-CoGlc,

dichloromethane

 doses (250 and 500 g/hL)

 and ethanol extractive free cork after air removal

(CKFI75250

 and

CKFI75500).

malvidin-3-coumaroylglucoside.

delphinidin-3-acetylglucoside,

delphidin-3-coumaroylglucoside,

Cya-3-AcGlc,

 Data within a column followed by the

Cya-3-CoGlc,

 cyanidin-3-

X

 s; means within a column followed by the same letter are not significantly

 25.02

 0.09a 7.74

 0.61a

28.09

 0.56b

10.57

 0.18b

0.66

 0.00b

 different (Tukey, p 0.05). Del-3-Glc,

0.67

 0.01a

0.50

 0.01c

0.31

delphinidin-3-glucoside,

 Cya-3-Glc, cyanidin-3-acetylglucoside,

 Pet-3-AcGlc,

cyanidin-3-glucoside,

 Pet-3-

 0.01b

 22.77

 0.07a 8.27

 0.26a

28.57

 0.44b

10.56

 0.29b

0.67

 0.03b

0.68

 0.02a

0.50

 0.01c

0.31

 0.02ab

 22.50

 0.30a 8.48

 1.10a

29.23

 0.02ab

10.81

 0.01ab 0.69

 0.01b

0.55

 0.00b

0.52

 0.01c

0.33

 0.00ab

 21.92

 1.79a 8.55

 1.16a

29.61

 0.28a

11.02

 0.20ab 0.80

 0.08a

0.57

 0.03b

0.54

 0.00b

0.33

 0.04ab

24.11

 1.55a

9.28

 1.53a

30.02

 0.25a

11.23

 0.18ab

0.84

 0.00a

0.72

 0.01a

0.57

 0.00a

0.39

 0.00a

3.89

3.37

3.28

3.15

3.12

 0.02b

 0.15b

 0.03b

 0.18b

Air Depleted and Solvent Impregnated Cork Powder as a New Natural and Sustainable Wine…

 0.04a

 Catechin

t-Caftaric acid Coutaric acid Caffeic acid

 0.01 7.93

 0.06ab

13.42

 0.23 4.67

 0.08ab

154.08

 2.30ab 1.34

 0.02c 0.84

p-Coumaric

 acid Ferulic acid Caffeic acid ethyl ester Coumaric acid ethyl ester

 0.05ab

26.68

 0.56a 1.30

 0.04a 1.18

 0.01a

12.04

 0.32ab

 1.15

 0.02 7.71

 0.19ab

13.66

 1.15 4.53

 0.01b

154.04

 0.36ab 1.42

 0.04c 0.83

 0.04ab

25.89

 0.91a 1.29

 0.05a

1.08

 0.28a

11.89

 0.48b

 1.14

 0.03 8.00

 0.05ab

13.59

 0.03 4.78

 0.03a

156.65

 1.05a

1.50

 0.00b 0.87

 0.01ab

26.69

 0.35a 1.31

 0.02b

1.23

 0.04a

12.61

 0.14ab

DOI: http://dx.doi.org/10.5772/intechopen.85691

 1.12

 0.02 7.66

 0.12b

13.10

 0.06a 4.55

 0.04b

150.37

 1.21b

1.24

 0.01d

0.79

 0.03b

25.66

 0.30a 1.24

 0.02a 1.43

 0.04a

12.09

 0.53ab

1.18

 0.00 8.24

 0.17a

13.58

 0.30a 4.77

 0.07a

155.84

 0.69a

1.58

 0.02a

0.98

 0.00a

26.04

 0.46a 1.37

 0.02a

1.49

 0.15a

13.70

 0.78a

 Del-3-Glc

 Cya-3-Glc

 Pet-3-Glc

 Peo-3-Glc

 Mal-3-Glc

Del-3-AcGlc

Cya-3-AcGlc

Mal-3-AcGlc

Del-3-CoGlc

Cya-3-CoGlc

Mal-3-CoGlc

Chromatic characteristics of red wines before (TF) and after treatment with natural cork and dichloromethane and ethanol extractive free cork after air removal and ethanol impregnation (CKNI and CKFI) and cork powders with a particle size below 75 μm at two application doses (250 and 500 g/hL).

