Comparison between the phenolic composition of Petit Verdot wines elaborated at different maceration/fermentation temperatures

Figures & data

Table 1. Oenological and colour parameters at the end of alcoholic fermentation of Petit Verdot wines elaborated at different temperatures of maceration and fermentation.

	17°C	21°C	25°C
Alcoholic content (% v/v)	15.36 ± 0.00^c	15.10 ± 0.18^b	14.68 ± 0.02^a
Glycerine (g/L)	4.08 ± 0.10^a	4.89 ± 0.70^ab	5.63 ± 0.14^b
Total acidity (g/L)	4.61 ± 0.01^a	4.70 ± 0.02^b	4.85 ± 0.03^c
pH	3.78 ± 0.00^b	3.78 ± 0.03^b	3.73 ± 0.00^a
Volatile acidity (g/L)	0.12 ± 0.01^a	0.13 ± 0.01^b	0.16 ± 0.01^c
L-malic acid (g/L)	1.43 ± 0.05	1.42 ± 0.02	1.38 ± 0.01
L*	18.20 ± 1.85	16.01 ± 0.78	15.40 ± 0.01
a*	50.42 ± 1.83	48.22 ± 0.96	47.66 ± 0.05
b*	28.58 ± 1.75	26.30 ± 1.12	25.60 ± 0.04
C*	57.96 ± 2.46	54.93 ± 1.38	54.10 ± 0.03
H*	29.52 ± 0.62^b	28.60 ± 0.54^ab	28.25 ± 0.06^a
Colour intensity	8.14 ± 0.76^a	8.97 ± 0.22^ab	9.47 ± 0.09^b
Tonality	0.60 ± 0.01^b	0.59 ± 0.00^b	0.57 ± 0.02^a

Values are the mean of triplicates. L*: luminosity; a*: redness; b*: yellow; C*: chroma; H*: hue angle. Different superscripts (^{a, b, c}) indicate significant differences between maceration temperature for α = 0.05 according to the Student–Newman–Keuls test.

Table 2. Concentration of anthocyanins (mg/L as malvidin-3-O-glucoside) at the end of alcoholic fermentation in Petit Verdot wines elaborated at different temperatures of maceration and fermentation.

	17°C	21°C	25°C
Cyanidin 3-O-glucoside	0.49 ± 0.02^a	0.61 ± 0.11^ab	0.66 ± 0.03^b
Cyanidin 3-O-acetylglucoside	0.18 ± 0.01	0.17 ± 0.03	0.15 ± 0.00
Cyanidin 3-O-coumaroylglucoside	0.07 ± 0.00	0.07 ± 0.01	0.11 ± 0.04
Peonidin 3-O-glucoside	1.73 ± 0.01^a	2.20 ± 0.28^b	2.11 ± 0.08^b
Peonidin 3-O-acetylglucoside	3.34 ± 0.02^a	3.73 ± 0.14^b	3.34 ± 0.03^a
Peonidin 3-O-coumaroylglucoside	0.77 ± 0.03	0.91 ± 0.12	0.82 ± 0.05
∑ Disubstituted	6.56 ± 0.09^a	7.70 ± 0.68^b	7.20 ± 0.24^ab
Delphinidin 3-O-glucoside	6.78 ± 0.10	7.48 ± 0.88	6.44 ± 0.09
Delphinidin 3-O-acetylglucoside	3.71 ± 0.10^ab	4.00 ± 0.47^b	3.18 ± 0.01^a
Delphinidin 3-O-coumaroylglucoside	0.84 ± 0.05^a	1.05 ± 0.10^b	0.89 ± 0.00^a
Petunidin 3-O-glucoside	14.97 ± 0.44^ab	16.57 ± 1.41^b	14.01 ± 0.22^a
Petunidin 3-O-acetylglucoside	7.17 ± 0.09^ab	7.73 ± 0.55^b	6.60 ± 0.16^a
Petunidin 3-O-coumaroylglucoside	1.05 ± 0.06^a	1.39 ± 0.16^b	1.25 ± 0.01^b
Malvidin 3-O-glucoside	191.14 ± 7.53^a	210.11 ± 7.51^b	196.26 ± 4.89^a
Malvidin 3-O-acetylglucoside	113.89 ± 4.36	122.65 ± 2.10	118.86 ± 4.02
Malvidin 3-O-coumaroylglucoside	24.83 ± 1.52^a	30.03 ± 2.02^b	29.58 ± 0.89^b
Malvidin 3-O-caffeoylglucoside	4.08 ± 0.06^a	4.53 ± 0.12^b	4.05 ± 0.20^a
∑ Trisubstituted	368.46 ± 13.90^a	405.54 ± 15.32^b	381.13 ± 10.28^ab
Vitisin A	2.78 ± 0.12^a	3.41 ± 0.15^b	3.53 ± 0.17^b
Vitisin B	1.87 ± 0.08	2.01 ± 0.12	1.89 ± 0.09
∑ Pyranoanthocyanins	4.65 ± 0.20^a	5.42 ± 0.27^b	5.42 ± 0.26^b
∑ Cyanidin type	0.73 ± 0.03	0.86 ± 0.14	0.92 ± 0.07
∑ Peonidin type	5.83 ± 0.06^a	6.84 ± 0.54^b	6.28 ± 0.17^ab
∑ Delphinidin type	11.33 ± 0.15	12.53 ± 1.44	10.51 ± 0.08
∑ Petunidin type	23.19 ± 0.58^ab	25.69 ± 2.13^b	21.86 ± 0.37^a
∑ Malvidin type	333.94 ± 13.41^a	367.32 ± 11.63^b	348.75 ± 9.80^ab
∑ Non-acylated	215.10 ± 7.91^a	236.97 ± 10.18^b	219.47 ± 5.12^a
∑ Acylated	159.92 ± 6.09^a	176.26 ± 5.81^b	168.85 ± 5.40^ab
∑ Total anthocyanins	379.66 ± 14.20^a	418.66 ± 16.26^b	393.74 ± 10.78^ab

Values are the mean of triplicates. Different superscripts (^{a, b, c}) indicate significant differences between maceration temperature for α = 0.05 according to the Student–Newman–Keuls test.

Table 3. Concentration of flavonols (mg/L as quercetin-3-glucoside) at the end of alcoholic fermentation in Petit Verdot wines elaborated at different temperatures of maceration and fermentation.

	17°C	21°C	25°C
Kaempferol-3-glucoside	1.25 ± 0.45	0.95 ± 0.03	0.98 ± 0.06
Kaempferol	0.42 ± 0.01^b	0.42 ± 0.01^b	0.39 ± 0.00^a
∑ Monosubstituted	1.67 ± 0.44	1.37 ± 0.04	1.38 ± 0.07
Quercetin-3-glucoside	6.73 ± 0.30^a	7.18 ± 0.18^b	8.11 ± 0.29^c
Quercetin-3-galactoside	2.56 ± 0.05	2.53 ± 0.22	2.56 ± 0.16
Quercetin-3-glucuronide	9.97 ± 0.53	10.22 ± 0.47	10.73 ± 0.25
Quercetin	1.74 ± 0.26	2.00 ± 0.01	1.79 ± 0.26
Isorhamnetin-3-glucoside	1.82 ± 0.03	2.00 ± 0.02	2.09 ± 0.27
∑ Disubstituted	22.83 ± 0.50^a	23.92 ± 0.84^a	25.27 ± 1.23^b
Myricetin-3-glucoside	17.74 ± 1.49^a	20.83 ± 1.28^b	20.42 ± 0.06^b
Myricetin-3-galactoside	2.70 ± 0.16^a	2.95 ± 0.04^b	2.88 ± 0.07^b
Myricetin-3-glucuronide	1.95 ± 0.23^a	2.40 ± 0.05^b	2.24 ± 0.13^b
Laricitrin-3-glucoside	9.20 ± 0.74^a	10.50 ± 0.13^b	10.18 ± 0.48^b
Laricitrin-3-galactoside	0.79 ± 0.02	0.81 ± 0.08	0.77 ± 0.01
Laricitrin	1.28 ± 0.11^b	1.17 ± 0.04^a	1.13 ± 0.00^a
Syringetin-3-glucoside	15.05 ± 1.42	16.97 ± 0.67	16.49 ± 1.52
∑ Trisustituted	48.70 ± 4.18^a	55.63 ± 2.10^b	54.12 ± 2.14^b
∑ Kaempferol type	1.67 ± 0.44	1.37 ± 0.04	1.38 ± 0.07
∑ Quercetin type	21.01 ± 0.53^a	21.92 ± 0.86^ab	23.18 ± 0.96^b
∑ Isorhamnetin type	1.82 ± 0.03	2.00 ± 0.02	2.09 ± 0.27
∑ Myricetin type	22.39 ± 1.88^a	26.18 ± 1.27^b	25.55 ± 0.13^b
∑ Laricitrin type	11.27 ± 0.88^a	12.48 ± 0.17^b	12.08 ± 0.49^ab
∑ Syringetin type	15.05 ± 1.42	16.97 ± 0.67	16.49 ± 1.52
∑ Non-methoxylated	45.06 ± 1.79^a	49.47 ± 0.37^b	50.10 ± 1.15^b
∑ Methoxylated	28.14 ± 2.33	31.45 ± 0.86	30.66 ± 2.28
∑ Total Flavonols	73.20 ± 4.12^a	80.92 ± 1.22^b	80.77 ± 3.44^b

Values are the mean of triplicates. Different superscripts (^{a, b, c}) indicate significant differences between maceration temperature for α = 0.05 according to the Student–Newman–Keuls test.

Table 4. Concentration of flavan-3-ol monomers and dimers, proanthocyanidins, and stilbenes (mg/L) at the end of alcoholic fermentation in Petit Verdot wines elaborated at different temperatures of maceration and fermentation.

	17°C	21°C	25°C
Catechin	21.79 ± 1.99^b	19.68 ± 0.24^a	19.08 ± 1.61^a
Epicatechin	10.80 ± 0.73^c	9.30 ± 0.65^b	8.15 ± 0.56^a
Gallocatechin	3.12 ± 0.26^a	3.83 ± 0.38^b	4.66 ± 0.06^c
Epigallocatechin	1.16 ± 0.10^a	1.71 ± 0.28^b	1.50 ± 0.30^ab
Catechin gallate	0.11 ± 0.03	0.09 ± 0.02	0.10 ± 0.02
Epicatechin gallate	0.41 ± 0.15	0.32 ± 0.15	0.46 ± 0.01
∑ Monomers	37.40 ± 2.39	34.93 ± 1.37	33.95 ± 2.50
Procyanidin B1	22.29 ± 0.29	22.59 ± 1.86	24.11 ± 1.72
Procyanidin B4	2.86 ± 0.53	2.64 ± 0.02	2.47 ± 0.25
Procyanidin B2	10.10 ± 1.06^b	9.00 ± 0.63^a	8.42 ± 0.33^a
Dimer 1 (Unknown dimer 1)	3.97 ± 0.00^b	3.03 ± 0.56^a	3.26 ± 0.14^a
Dimer 2 (Unknown dimer 2)	1.16 ± 0.04^c	0.97 ± 0.03^a	1.06 ± 0.01^b
∑ Dimers	40.37 ± 1.35	38.23 ± 3.03	39.33 ± 2.43
mDP^1	3.95 ± 0.22	3.93 ± 0.15	3.63 ± 0.18
Galloylation (%)	5.75 ± 0.37	5.20 ± 0.67	5.00 ± 0.17
Prodelphinidins (%)	27.2 ± 0.55	28.4 ± 0.05	29.2 ± 0.37
∑ Proanthocyanidins	305.39 ± 6.66	371.71 ± 12.2	519.38 ± 55.45
trans-piceid	0.05 ± 0.00^a	0.06 ± 0.01^b	0.06 ± 0.00^b
cis-piceid	0.08 ± 0.00^a	0.12 ± 0.01^b	0.12 ± 0.01^b
∑ Stilbenes	0.13 ± 0.01^a	0.18 ± 0.02^b	0.18 ± 0.02^b

Values are the mean of triplicates. mDP¹: mean degree of polymerisation. ∑Flavan-3-ol monomers and dimers, proanthocyanidins and stilbenes represents different superscripts (^{a, b, c}) indicate significant differences between maceration temperature for α = 0.05 according to the Student–Newman–Keuls test.

Table 5. Principal component analysis (PCA) applied to the data from phenolic compounds.

Principal component	Variance explained (%)	Total variance (%)	Variables highly correlated with the axis and their loadings
1	46.103	46.103	Peonidin 3-acetylglucoside (0.993)
			Delphinidin 3-coumaroylglucoside (0.976)
			Malvidin 3-glucoside (0.941)
			Malvidin 3-caffeoylglucoside (0.929)
			∑ Peonidin type (0.927)
			∑ Total anthocyanins (0.925)
			∑ Petunidin type (0.922)
			Petunidin 3-glucoside (0.912)
			∑ Malvidin type (0.883)
2	40.078	86.181	Quercetin-3-glucoside (0.981)
			Gallocatechin (0.973)
			Epigallocatechin (−0.962)
			∑ Disubstituted flavonols (0.911)
			∑ Non-methoxylated flavonols (0.861)
			Procyanidin B2 (−0.860)
			Vitisin A (0.859)
			∑ Quercetin type (0.849)

Figure 1. Plotting of the samples on the plane defined by the two principal components obtained by principal component analysis (PCA) of the data from phenolic compounds.