Enhancing Phenolic Maturity of Syrah with the Application of a New Foliar Spray

Abstract

Climate change is inducing earlier grape ripening, especially in warm vintages. This phenomenon is resulting in unbalanced wines an alcohol concentration that is too high and titratable acidity that is low, along with a high pH level without the desired level of phenolic maturity. Final wine quality notably depends on the phenolic composition of the grapes and the extractability of these compounds. This research was designed to test a new foliar spray, called LalVigne (R) MATURE, for its capacity to create a balance between sugar development and phenolic maturity. It is a formulation of 100% natural, inactivated wine yeast derivatives. This foliar spray was tested on Syrah vines in two vintages (2012 and 2013) in a cool-climate wine region (Eger, Hungary). The spray acted as an elicitor, stimulating the synthesis of several secondary metabolites. The changes in anthocyanin extractability and texture characteristics of the grape berries were followed during ripening. Experimental wines were made at three separate harvest times in each vintage. Standard analytical parameters were evaluated for grapes and wines, as well as for resveratrol. Grapes from the treated vines had thicker skins than the controls at all sampling dates in both vintages. The phenolic potential (especially anthocyanin concentration and extractability) of the foliar spray-treated grapes was greatly improved. Our experiment showed that phenolic ripening can be enhanced using the foliar spray, and that its application was useful in different vintages.

Full text

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S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
*Corresponding author: E-mail address: szvillango@szbki-eger.hu [Tel.: +36 37 518 310]
Acknowledgements: This project was supported by TÁMOP grants (TÁMOP-4.2.2/B-10/1-2010-0023 and TÁMOP-4.2.1/B-09/1/KMR-2010-0005) from the
European Union and the János Bolyai Postdoctoral Fellowship (Zsolt Zsó). We would like to thank Lallemand Inc. and Kokoferm Ltd. for the foliar spray and
yeast products used during the experiment. We also thank Gróf Buttler Winery for providing the experimental sites in its vineyard. The authors further wish to
thank Ágnes Herczeg, Carlos Suárez Martínez, Karl Burger and Anthony Silvano, for their valuable advice, and Dr Geoffrey R. Scollary, Dr Fernando Zamora
Marín and Dr Joan Miquel Canals, for their help in revising the manuscript
Enhancing Phenolic Maturity of Syrah with the Application of a
New Foliar Spray
Sz. Villangó1,5*, Gy. Pásti1, M. Kállay1, A. Leskó1, I. Balga2, A. Donkó3, M. Ladányi4, Z. Pál5, Zs. Zsó5
(1) Department of Oenology, Institute of Viticulture and Oenology, Corvinus University of Budapest, Budapest, Hungary
(2) Department of Chemistry, Wine Chemistry and Oenology, Institute of Food Sciences, Eszterházy Károly College, Eger,
Hungary
(3) Department of Viticulture, Institute of Viticulture and Oenology, Corvinus University of Budapest, Budapest, Hungary
(4) Department of Biometrics and Agricultural Informatics, Corvinus University of Budapest, Budapest, Hungary
(5) KRC Research Institute for Viticulture and Oenology, Eger Kőlyuktető, P.O. Box 83, Eger, Hungary
Submitted for publication: March 2015
Accepted for publication: April 2015
Key words: Anthocyanin extractability, phenolic maturity, foliar spray, berry ripening, berry texture, resveratrol
Climate change is inducing earlier grape ripening, especially in warm vintages. This phenomenon is
resulting in unbalanced wines an alcohol concentration that is too high and titratable acidity that is low,
along with a high pH level without the desired level of phenolic maturity. Final wine quality notably depends
on the phenolic composition of the grapes and the extractability of these compounds. This research was
designed to test a new foliar spray, called LalVigne® MATURE, for its capacity to create a balance between
sugar development and phenolic maturity. It is a formulation of 100% natural, inactivated wine yeast
derivatives. This foliar spray was tested on Syrah vines in two vintages (2012 and 2013) in a cool-climate
wine region (Eger, Hungary). The spray acted as an elicitor, stimulating the synthesis of several secondary
metabolites. The changes in anthocyanin extractability and texture characteristics of the grape berries
were followed during ripening. Experimental wines were made at three separate harvest times in each
vintage. Standard analytical parameters were evaluated for grapes and wines, as well as for resveratrol.
Grapes from the treated vines had thicker skins than the controls at all sampling dates in both vintages.
The phenolic potential (especially anthocyanin concentration and extractability) of the foliar spray-treated
grapes was greatly improved. Our experiment showed that phenolic ripening can be enhanced using the
foliar spray, and that its application was useful in different vintages.
INTRODUCTION
Nowadays, wine consumers prefer well-structured wines
with deep colour, fruit scents, soft tannins and a pleasant
mouthfeel (Bruwer et al., 2011). These kinds of wines can
be made from well-ripened grapes with an optimal level of
phenolic and technological (sugar) maturity, but not from
over-ripened grapes. Nevertheless, the changing climate
modies the ripening process notably. In cool-climate wine
regions, such as the Eger wine district in Hungary, we can
count on more frequent extreme weather events, including
uneven precipitation, heat waves and droughts (Schultz,
2000). In dry and hot vintages, the ripening process is faster
and the balance between phenolic and technological (sugar)
maturity may not be maintained (Hannah et al., 2013). This
results in an increase in the sugar concentration and, in
parallel, a rapid decrease in the titratable acidity, resulting
in unbalanced wines that are too alcoholic. At the same time,
the lack of optimal phenolic maturity results in wines with
green and astringent tannins (Jones et al., 2005). On the other
hand, the ripening is slowed in a rainy, cool vintage, and late
ripening varieties (such as Cabernet Sauvignon, Cabernet
Franc and Syrah) cannot reach optimal maturity (Jackson &
Lombard, 1993).
Several technological applications can be used in order
to reduce these negative effects. Cluster thinning (Guidoni
et al., 2002; Prajitna et al., 2007), girdling (Singh Brar et al.,
2008; Koshita et al., 2011) and early defoliation (Poni et al.,
2006; 2009; Kemp et al., 2011; Gatti et al., 2012; Lee &
Skinkis, 2013) are reported to have a benecial effect on
phenolic maturity, especially on anthocyanin and avonoid
synthesis. The resveratrol content of the grape varies
considerably and depends on many viticultural factors,
including climate, terroir, grape variety, fungal infections
and yield (Jeandet et al., 1995; Bavaresco, 2003; Bavaresco

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
Enhancing Phenolic Maturity of Syrah
305
et al., 2007; Prajitna et al., 2007). There are also some
papers dealing with the increasing resveratrol concentration
in grapes using elicitors (Vezzulli et al., 2007; Santamaria
et al., 2011).
Beyond the above-mentioned techniques, a new foliar
spray for enhancing phenolic maturity was developed
recently and was examined for its effects. In addition, Syrah
is a new cultivar to the Eger wine region, where there is only
limited cultivation experience with it.
The aim of this study was to 1) describe the effects of
the application of this new foliar spray on grape phenolic
maturity and 2) describe some aspects of the responses of
a “new” variety (Syrah, Vitis vinifera L.) in a cool-climate
wine region (Eger, Hungary).
MATERIALS AND METHODS
Description of the experimental site and the experimental
design
The experiment took place at Nagy-Eged hill, a commercial
vineyard (lat. 47°55’31.84” N; long. 20°24’42.32” W,
elevation 430 m above sea level, asl) in the Eger wine region
(northeast Hungary). The vineyard’s shallow soil is based on
limestone. This site met the criteria for an investigation of
a new foliar spray designed to enhance phenolic maturity,
because in warm vintages the sugar accumulation is very fast
at Nagy-Eged hill, leading to alcoholic, unbalanced wines.
Besides, the desired level of phenolic maturity cannot be
achieved in most vintages. The trial was performed over two
consecutive vintages, in 2012 and 2013.
Ten-year-old Syrah (clone ENTAV-INRA® 877) vines
grafted onto Teleki 5C at a spacing of 2.4 m x 0.8 m with
a south-north row orientation were investigated. The vines
were trained to a unilateral cordon at a height of 0.6 m and
were pruned to four spurs, each bearing two nodes. A trial
site of six rows was selected for each treatment (three control
(unsprayed, C) and three treated (sprayed, LM) rows). Each
row was divided into three blocks. One block contained 25 to
29 vines. At the same harvest time, three blocks per treatment
were harvested, resulting in three replicates per treatment. The
leaf spray, LalVigne® MATURE, is a formulation of 100%
natural, inactivated wine yeast (Saccharomyces cerevisiae)
derivatives (specically designed to be used with the patent
foliar application technology WO/2014/024039, Lallemand
Inc., Canada). It is non-pathogenic, non-hazardous, food
grade and non-GMO. The product is already registered in
many countries and in the process of authorisation in others.
Two applications of 1 kg/ha were done. The rst one was
at the beginning of véraison, the second one 12 days later.
The powder was diluted in water without using an adjuvant.
The whole canopy was sprayed using a motorised backpack
sprayer.
There were three harvest dates (2012-09-06.,
2012-09-13., 2012-09-27, and 2013-09-12, 2013-09-19 and
2013-10-03) in each vintage for both the control and treated
vines. Establishing as reference the commercial harvest date
of the Gróf Buttler Winery, which effectively was the second
harvest in our trial, the rst harvest took place one week ear-
lier and the third harvest two weeks later than the reference.
One vine block represented one wine repetition per treatment
at each harvest date. Véraison commenced in the rst week
of August in 2012, and one week later in 2013.
Climatic data
Climatic data were monitored by an automatic weather sta-
tion (Boreas Ltd. Érd, Hungary), approximately 300 m from
the trial site.
Berry sampling
Three sets of 20 kg of grapes, with each set from 25 to 29
vines, were carefully harvested by hand for both treatments
at each harvest date, and transported immediately to the ex-
perimental winery. Three 1 kg samples from each treatment
were collected at random from several clusters before vini-
cation. The berries were selected randomly from the upper,
middle and lower parts of the bunches. All the berry samples
were prepared and analysed within two hours after the har-
vest.
For the texture analysis, 50 berries with pedicels were
randomly removed from the clusters and examined visually
before texture analysis. One berry represented one repetition
of this measurement. Damaged berries were rejected.
A total of 150 berries were selected separately for phe-
nolic measurements (Glories method), and these berries
were subdivided into two equal groups for the pH 1 and pH
3.4 solutions. The measurement was done in triplicate, and
25 berries were used for each repetition.
Three additional sets of 100 grape samples were selected
for weight determination and grape composition analysis.
Grape analysis
The analytical methods recommended by the OIV (2014)
were used to determine titratable acidity and the pH of the
grapes. The sugar content (expressed as °Brix) of the grape
juices was determined at 20°C, using a hand-held refractom-
eter (Atago MASTER-α, Japan).
Assessment of grape phenolic maturity
The phenolic potential of the grapes was calculated accord-
ing to the method described by Saint-Cricq et al. (1998). This
involved grinding the grapes with a blender and macerating
for four hours with buffer solutions at two pH values (1.0 and
3.4). The original method proposed a buffer of pH 3.2, but
this was adjusted to 3.4, as it is more relevant to the grapes
from this region. The indices of phenolic maturity were cal-
culated according to Glories and Augustin (1993): potential
anthocyanins (A1), extractable anthocyanins (A3.4), cell
maturity index (EA%) and seed maturity index (SM%). All
the measurements were done in triplicate.
The following equations were used:
EA (%) = [(A1 − A3.4) / A1] × 100
SM (%) = [(A280 − ((A3.4 / 1000) × 40)) / A280] × 100
Measurements of berry physical properties
A TA.XTplus Texture Analyzer (Stable Micro System, Sur-
rey, UK) with a HDP/90 platform and 30 kg load cell was
used to follow the grape physical properties. Exponent
6.1.4.0 software was used for the data evaluation. All op-
erative conditions were applied according to Letaief et al.
(2008b) and Zsó et al. (2014). Briey, a P/35 probe was

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
306
Enhancing Phenolic Maturity of Syrah
used to determine berry hardness (BH). Berries of approxi-
mately the same size, with their pedicel attached, were gently
removed from the bunch and laid on the plate of the analyser.
After this, they were compressed to 25% of their diameter.
The P/2N needle was applied to conduct a puncture test. A
second set of berries with their pedicels were removed from
the bunch, laid on the plate of the analyser and then punc-
tured in the lateral face (Letaief et al., 2008a). The skin break
force (Fsk), skin break energy (Wsk) and Young’s modulus of
berry skin (Esk) were calculated from the puncture test data
using Exponent 6.1.4.0 software. Berry skin thickness (Spsk)
was measured using a P/2 probe with 2 mm diameter. For this
measurement, approximately 0.25 cm2 of skin was removed
from the lateral face of the berry. The skin was carefully and
gently cleaned of pulp and then placed on the platform, after
which the test was conducted as described by other authors
previously (Letaief et al., 2008a; 2008b; Río Segade et al.,
2008). The skin thickness is given by the distance (travel)
between the point corresponding to the probe contact with
the berry skin and the platform base during the compression
test. For seed hardness tests, one seed was removed from the
berry and placed on the platform on its lateral side. The seeds
were crushed with the P/35 probe. The seed break force (Fs),
seed break energy (Ws) and Young’s modulus of the seed (Es)
were also calculated using Exponent 6.1.4.0.
Wine analysis
The analytical methods recommended by the OIV (2014)
were used to determine the ethanol content, titratable acidity
and pH of the wines.
The total phenolics of the wines were analysed by the
Folin-Ciocalteu method (Singleton & Rossi, 1965) and the
results expressed as gallic acid equivalents (GAE mg/L). The
quantity of leuco-anthocyanins (avan-3,4-diols) was deter-
mined as described by Flanzy et al. (1969). The bisulphite
bleaching method was used to determine the anthocyanin
content of the grape extracts and wines (Ribéreau-Gayon &
Stonestreet, 1965), while the total catechins (avan-3-ols)
were measured using the vanillin assay according to Amer-
ine and Ough (1980). The colour intensity (A420 + A520 + A620)
and hue (A420/A520) of the wines were determined using the
method described by Glories (1984). Phenolic components
were measured by spectrophotometer (UVmini-1240 CE
UV-VIS, Shimadzu, Japan). The gelatine and HCl indices
(Ribéreau-Gayon et al., 2006) were also calculated. All the
measurements were performed in triplicate.
Qualitative and quantitative determination of resveratrol
components in wines by HPLC
The analysis of the resveratrol compounds was carried out
according to Kállay and Török (1997). The wine samples
were ltered rst on lter paper, then on a membrane of
0.45 μm. The eluent for the isocratic HPLC analysis consist-
ed of a 5:5:90 mixture (v/v %) of acetonitrile:methanol:redist
illed water. All the measurements were done in triplicate, and
the wine samples were directly injected after ltration with-
out dilution, in a quantity of 20 μL. Operating conditions and
chromatograph settings were as follows: a HP Series 1050
HPLC-apparatus with a normal phase LiChrospher® 100 CN
(250 x 4 mm, 5 μm) column (Merck, Germany) was used
for the measurements. The detector was a HP Series 1050.
The ow was set at 2 mL/min at 30°C with the detection
wavelength at 306 nm. The methanol and acetonitrile used
for the experiment were of HPLC grade, while other chemi-
cals were of analytical purity. Trans-resveratrol (99%) stan-
dard was purchased from Sigma-Aldrich (Germany). Trans-
piceid standard was received from the San Michele all’Adige
Research and Innovation Centre. Cis-isomers were produced
by UV irradiation of the trans-isomers (Sato et al., 1997).
The detection limit was 0.1 mg/L.
Microvinication process
Three sets of 20 kg of grapes were crushed, destemmed and
sulphited (1 mL of 5% aqueous SO2 solution for every 1 L of
mashed grapes) in the experimental winery at each harvest
date. Macerations were conducted in 30 L plastic containers,
and all grape repetitions were fermented separately. Three
experimental wine replicates were made at each harvest time
for each respective treatment. After the grapes had been pro-
cessed the containers were transported immediately to the
cellar to ensure constant ambient temperature (13°C) from
the beginning to the end of maceration. After 24 hours of cold
maceration, selected active dry yeasts (20 g of dry yeast/100
kg of processed grapes) (Uvaferm VN, Lallemand Inc.) and
yeast nutrients (30 g/100 kg of processed grapes) (Uvavital,
Lallemand Inc.) were added. The maceration lasted for 23
days. The cap was punched down twice a day throughout the
skin-contact period. The wines also were inoculated with 10
mg/L lactic acid bacteria (Uvaferm Alpha, Lallemand Inc.)
at the end of alcoholic fermentation. After 23 days the wines
were pressed at 1.5 bar in a 30 L membrane press. Free-run
and press wines were mixed. After malolactic fermentation
had occurred, the wines were racked and transported to the
laboratory for analysis. All the wines were stored at 13°C for
several days until the moment of the analysis, and no sulphur
was added prior to analysis.
Sensory analysis
All the wines were tasted by a group of 17 expert oenologists.
Blind tests were carried out by comparing in pairs (control
(C) vs. treated (LM)) the wines obtained from the three dif-
ferent harvest dates in both vintages. The wines were evalu-
ated sensorially using the 100-point OIV (1994) method. In
all the cases, the objective was for the tasters to name which
wines they preferred and for what reason.
Statistical analysis
Statistical analysis was conducted using IBM SPSS 20 (IBM
Corp., Armonk, NY, USA) software. Values were compared
by multivariate ANOVA test with three factors (the effects of
vintage: 2012, 2013, treatment: C (control), LM (LalVigne®
MATURE) and harvest dates), followed by between-subject
effect tests. The homogeneity of variances was checked by
Levene’s test. In the case of signicant effect of the harvest
dates, Tukey’s test or the Games-Howell post hoc test was
used for mean separation, according to whether or not the
homogeneity of the variances held.

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
Enhancing Phenolic Maturity of Syrah
307
RESULTS
Climatic characteristics for 2012 and 2013
Fig. 1 shows the climatic characteristics of the two vintages.
The weather in 2012 can be considered as dry (total rainfall
was 439.2 mm, compared to the 50-year average of 589.6
mm) and warm (average year temperature was 12.5°C,
compared to the 50-year average of 10.7°C). On the other
hand, 2013 can be regarded as a cooler vintage (total rainfall:
663 mm, average year temperature: 12.2°C), although the
weather was somewhat cooler with more rain during the
owering and ripening stage than in 2012.
Yield, grape juice sugar concentration, acidity, pH, berry
weight, cell and seed maturity indices
The average yield per vine was 0.63 kg (control) and 0.65 kg
(treated) in 2012, and 0.99 kg (control) and 0.92 kg (treated)
in 2013. An average of seven bunches were grown per vine
in both years.
Table 1 shows the standard grape juice parameters. The
grapes reached a greater level of technological maturity in
2012 (maximum sugar concentration: 24.3°Brix) compared
to 2013 (maximum sugar concentration: 21.2°Brix). Indeed,
the berry sugar concentration in 2012 exceeded that of
2013 by 15 to 25%. There also were notable differences in
the case of titratable acidity, with the values in 2013 being
signicantly higher. The lowest concentration was 8.6 g/L.
The weight loss of the berries during ripening was due to
dehydration. There was some rain between the second and
the third harvest dates in 2012, however, which resulted in
heavier berries. Clearly, the vintage had a very strong effect
on all the parameters, as can be seen in Table 1.
The Glories indices, which provide a prediction of
phenolic compounds in the resulting wines (Kontoudakis
et al., 2010) are given in Table 2. In general, the lower the
EA% and SM% values, the riper the berry. In most cases the
regular range for A1, EA% and SM% varied between 500
to 2 000 mg/L, 70% to 20% and 60% to 0% respectively
(Ribéreau-Gayon et al., 2006). The A1 and A3.4 values
indicate a good anthocyanin concentration, especially in
2012. Interestingly, the EA% values showed an increase in
some cases during ripening, implying that the extractability
of the anthocyanins decreased. None of the factors affected
the seed maturity index (SM%).
Grape texture properties
Table 3 shows the texture parameters of the berries. The
berries became softer (BH) during ripening. The signicant
increase observable in 2012 was due to the rainfall during
FIGURE 1
Average air temperature (lines) and monthly sum of precipitation (bars) for 2012 and 2013 at the experimental site (data from
automatic weather stations).

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
308
Enhancing Phenolic Maturity of Syrah
TABLE 1
Standard grape composition parameters.
Parameter Vintage Harvest date
2012-09-06 / 2013-09-12 2012-09-13 / 2013-09-19 2012-09-27 / 2013-10-03
Treatment
C LM C LM C LM
°Brix 2012 22.9 ± 0.3aα 23.6 ± 0.1bα 23.7 ± 0.1aβ 24.0 ± 0.2bβ 24.3 ± 0.1aγ 24.3 ± 0.1aβ
2013 18.5 ± 0.2aα 18.2 ± 0.1aα 19.0 ± 0.31aα 20.4 ± 0.2bβ 21.2 ± 0.3aβ 21.0 ± 0.2aγ
* * * * * *
Titratable acidity (g/L) 2012 7.6 ± 0.1aα 6.3 ± 0.0bα 5.1 ± 0.1aβ 5.3 ± 0.1bβ 5.5 ± 0.1aγ 5.9 ± 0.0bγ
2013 10.8 ± 0.1aα 9.4 ± 0.1bα 10.2 ± 0.1aβ 8.9 ± 0.1bβ 8.6 ± 0.1aγ 9.2 ± 0.1bγ
* * * * * *
pH 2012 3.14 ± 0.02aα 3.23 ± 0.00bα 3.32 ± 0.01aβ 3.34 ± 0.01bβ 3.25 ± 0.01aγ 3.34 ± 0.01bβ
2013 2.90 ± 0.01aα 2.89 ± 0.00aα 2.93 ± 0.01aβ 3.02 ± 0.02bβ 2.94 ± 0.01aβ 2.91 ± 0.01bα
* * * * * *
Weight of 100 berries (g) 2012 127.83 ± 1.39aα 134.68 ± 2.16bα 125.23 ± 3.10aα 121.54 ± 1.24aβ 134.60 ± 2.51aβ 136.92 ± 3.09aα
2013 173.45 ± 3.43aα 178.98 ± 4.61aα 171.41 ± 6.89aα 175.60 ± 6.06aα 147.11 ± 5.47aβ 147.46 ± 5.79aβ
* * * * * *
Values marked with different Roman letters mean signicant differences between the treatments within the same year and same harvest date. Different Greek letters mean signicant differences between
harvest dates within the same year and same treatment. * means signicant differences between the years within the same treatments and harvest dates. For separation, Tukey’s and Games-Howell’s post
hoc test was used at p = 0.05. Each value represents the average ± standard error of three replicates. C = control, LM = foliar sprayed
TABLE 2
Measures of phenolic maturity in grapes.
Parameter Vintage Harvest date
2012-09-06 / 2013-09-12 2012-09-13 / 2013-09-19 2012-09-27 / 2013-10-03
Treatment
CLMCLMCLM
A1 (mg/L) 2012 1754 ± 41aα 1781 ± 82aα 1781 ± 48aα 1888 ± 34bα 1834 ± 124aα 1736 ± 112aα
2013 1084 ± 61aα 1273 ± 68bα 1038 ± 58aα 1386 ± 49bαβ 1356 ± 57aβ 1433 ± 46aβ
******
A3.4 (mg/L) 2012 828 ± 79aα 958 ± 26bα 801 ± 84aα 839 ± 26aβ 725 ± 49aβ 792 ± 16bγ
2013 559 ± 37aα 702 ± 40bα 593 ± 22aα 734 ± 47bα 602 ± 28aα 761 ± 29bβ
*****
EA (%) 2012 52.9 ± 3.4aα 46.1 ± 3.8bα 54.9 ± 5.8aα 55.5 ± 1.7aβ 60.4 ± 3.2aβ 54.2 ± 2.9aβ
2013 48.2 ± 6.4aα 44.7 ± 5.6aα 42.6 ± 5.1aα 46.9 ± 4.8aα 55.6 ± 1.5aβ 46.9 ± 1.4bα
* *
SM (%) 2012 58.3 ± 2.7aα 55.8 ± 2.5aα 55.8 ± 9.1aα 65.4 ± 1.0aα 66.5 ± 5.8aα 56.2 ± 8.7aα
2013 69.5 ± 3.5aα 65.5 ± 3.8aα 57.5 ± 10.6aα 67.3 ± 2.0aα 49.0 ± 14.2aα 56.1 ± 14.0aα
* *
Values marked with different Roman letters mean signicant differences between the treatments within the same year and same harvest date. Different Greek letters mean signicant differences between
harvest dates within the same year and same treatment. * means signicant differences between the years within the same treatments and harvest dates. For separation, Tukey’s test and the Games-Howell
post hoc test were used at p = 0.05. Each value represents the average ± standard error of three replicates. C = control, LM = foliar sprayed

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
Enhancing Phenolic Maturity of Syrah
309
TABLE 3
Berry physical properties.
Parameter Vintage Harvest date
2012-09-06 / 2013-09-12 2012-09-13 / 2013-09-19 2012-09-27 / 2013-10-03
Treatment
C LM C LM C LM
BH (N) 2012 3.271 ± 0.578aαβ 3.552 ± 0.672bαβ 3.114 ± 0.667aα 3.252 ± 0.684aα 3.450 ± 0.737aβ 3.822 ± 0.947bβ
2013 3.940 ± 0.899aα 4.011 ± 0.873aα 3.751 ± 0.745aα 3.183 ± 0.617bβ 3.266 ± 0.768aβ 3.134 ± 0.692aβ
* * * * *
Fsk (N) 2012 0.472 ± 0.066aα 0.433 ± 0.063bα 0.409 ± 0.073aβ 0.422 ± 0.087aα 0.442 ± 0.077aαβ 0.453 ± 0.102aα
2013 0.450 ± 0.106aα 0.434 ± 0.097aα 0.469 ± 0.098aα 0.414 ± 0.105bα 0.458 ± 0.094aα 0.415 ± 0.089bα
*
Esk (N/mm) 2012 0.437 ± 0.111aα 0.451 ± 0.107aα 0.455 ± 0.091aαβ 0.450 ± 0.128aα 0.489 ± 0.076aβ 0.520 ± 0.148aβ
2013 0.559 ± 0.103aα 0.525 ± 0.085aα 0.476 ± 0.077aαβ 0.499 ± 0.077aα 0.332 ± 0.042aβ 0.371 ± 0.061bβ
* * * * *
Wsk (mJ) 2012 0.270 ± 0.102aα 0.260 ± 0.075aα 0.232 ± 0.075aβ 0.252 ± 0.104aα 0.244 ± 0.071aβ 0.247 ± 0.096aα
2013 0.226 ± 0.081aα 0.233 ± 0.088aα 0.283 ± 0.100aβ 0.224 ± 0.101bα 0.342 ± 0.102aγ 0.271 ± 0.082bβ
***
Spsk (mm) 2012 0.185 ± 0.038aα 0.227 ± 0.042bα 0.197 ± 0.028aα 0.220 ± 0.037bα 0.197 ± 0.038aα 0.228 ± 0.030bα
2013 0.190 ± 0.033aα 0.210 ± 0.028bα 0.191 ± 0.030aα 0.219 ± 0,030bα 0.190 ± 0.030aα 0.223 ± 0.035bα
Fs (N) 2012 38.50 ± 8.26aα 38.88 ± 9.64aα 38.52 ± 9.17aα 37.61 ± 8.12aα 37.68 ± 8.11aα 39.91 ± 10.51aα
2013 30.77 ± 7.13aα 33.85 ± 5.78aα 35.60 ± 6.02aβ 34.61 ± 6.42aα 33.35 ± 6.14aαβ 33.14 ± 8.11aα
* * * * *
Es (N/mm) 2012 69.66 ± 14.51aα 73.46 ± 11.82aα 68.31 ± 12.29aα 68.58 ± 14.79aα 73.94 ± 15.33aα 73.12 ± 15.33aα
2013 77.67 ± 13.75aα 78.64 ± 12.91aα 82.55 ± 15.22aα 87.36 ± 13.18aβ 82.86 ± 14.24aα 80.37 ± 16.54aα
* * * * * *
Ws (mJ) 2012 9.73 ± 2.90aα 9.77 ± 3.42aα 9.92 ± 3.65aα 9.56 ± 3.15aα 9.48 ± 3.13aα 10.25 ± 3.65aα
2013 5.77 ± 2.24aα 6.85 ± 1.88aα 7.13 ± 2.13aβ 6.59 ± 2.32aα 6.37 ± 1.78aαβ 6.50 ± 2.27aα
* * * * * *
Values marked with different Roman letters mean signicant differences between the treatments within the same year and same harvest date. Different Greek letters mean signicant differences between
harvest dates within the same year and same treatment. * means signicant differences between the years within the same treatments and harvest dates. For separation, Tukey’s test and the Games-Howell
post hoc test were used at p = 0.05. Each value represents the average ± standard error of 50 replicates. C = control, LM = foliar sprayed

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
310
Enhancing Phenolic Maturity of Syrah
the second and third harvest periods. Changes in skin break
force (Fsk) showed a very similar pattern to Wsk related to the
treatments and the harvest time. The impact of the leaf spray
caused a signicant increase in skin thickness (Spsk). The
values were above 0.2 mm in the case of the treated grapes at
all harvest dates and in both years. There was no correlation
between skin thickness (Spsk) and skin break force (Fsk)
values. The seed texture parameters remained unchanged,
despite the treatment between the harvest dates. However,
the vintage had a very strong effect on these parameters.
Wine composition
Table 4 summarises the main wine parameters. The wines
had a wide range of alcohol concentration (between 11.28%
v/v and 15.55% v/v). However, the foliar spray did not
inuence this parameter. We found signicant differences
between the titratable acidity and pH in the rst phase of
ripening, but the differences were no longer signicant by
the second and third harvest dates.
The total polyphenol values were independent of the
foliar spray treatment. In 2012 we measured signicantly
higher (above 2 000 mg/L) values than in 2013 (concentration
between 1 025 and 1 304 mg/L). The leuco-anthocyanin and
anthocyanin concentrations were found to be signicantly
higher in the treated wines in three instances: at the second
and the third harvest dates in 2012, and at the second harvest
date in 2013 (although only for anthocyanins). The weather
conditions in 2012 favoured anthocyanin synthesis up to
796 mg/L. By contrast, the unfavourable vintage in 2013
resulted in a signicantly lower anthocyanin concentration
(Table 4). The impact of the foliar spray and harvest date on
catechin levels is unclear. The colour intensity (A420 + A520
+ A620) correlated well with the increasing concentration of
anthocyanins. The values of colour hue (A420/A520) represent
a bluish tone, but this is typical for young red wines (Boulton,
2001).
The gelatine index increased signicantly between the
rst and the third harvest dates in the foliar spray-treated
grapes in 2012. In 2013 the differences between harvest dates
were smaller, and the values also were much lower than in
2012 and less than the optimal value due to the unfavourable
weather conditions (Ribéreau-Gayon et al., 2006). During
tastings the wines were characterised by green, unripe
tannins. HCl indices showed a marked variation, from 4.34
to 12.99. The foliar spray treatment increased this parameter,
but the difference was signicant only at the second harvest
date in 2012, and at the third harvest date in 2013.
Table 5 shows the changes in resveratrol concentration
in the wines. The majority of resveratrol was found in
the wines as the isomeric forms of piceid (resveratrol
glycoside). In 2012 and 2013, cis- and trans-resveratrol
were not detected in the control wines at the rst harvest
date. Trans-resveratrol was also absent in the treated wines
at the second harvest date in 2013. Treated wines contained
this compound from the rst harvest date. Under the effect
of the foliar spray, total resveratrol concentration increased
especially in the rst phase of ripening. The differences in
total resveratrol concentration were not signicant in three
cases: at the second harvest dates in both years, and at the
third harvest date in 2012.
Sensory analysis
All the tasters were able to differentiate between the control
and the treated wines. Wines made from foliar spray-treated
grapes were preferred and received higher scores than the
controls (data not shown). Vintage had a very strong effect
on the sensory quality. In 2013 the average points were much
lower for all the wines, but the positive impact of the foliar
spray remained sensible.
DISCUSSION
The foliar spray treatment had a signicant effect on the
titratable acidity and pH of the grapes, with the treated
berries containing less acid. This is probably due to the
higher berry respiration as an effect of faster ripening
(Sweetman et al., 2009). There was a positive effect of the
leaf spray treatment on both total (A1) and potential (A3.4)
anthocyanins, favouring their accumulation in both years and
at nearly all harvest dates. Several phenomena may generally
trigger the higher anthocyanin concentration of the wines.
These include a benecial change in the berry skin/esh
ratio (Kennedy et al., 2002; Ojeda et al., 2002), increased
extractability (Río Segade et al., 2011) and intensive
anthocyanin synthesis (Downey et al., 2004; Yamane et al.,
2006; Koshita et al., 2011). In addition, during anthocyanin
extraction in winemaking it also is necessary to take into
account the changes in grape skin cell wall composition
and structure, because this can modify the extractability
(Hanlin et al., 2010). The foliar spray-treated grapes reached
a greater level of phenolic maturity in both years, as can
be seen in the results for the rst and third harvests (values
of EA (%) are lower; see Table 3). The absolute (A1) and
extractable pigment (A3.4) concentration were also higher
due to the foliar spray in both years, except for one instance
in 2012. At the third harvest date the treated grapes had a
lower A1 value. Vintage had a signicant inuence on all the
Glories parameters except for SM%. As can be seen from
the data in Table 2, SM% values did not match the optimal
criteria (Ribéreau-Gayon et al., 2006) for ripeness in several
cases. Values higher than 60% mean that the seeds were not
sufciently ripe, and thus a long fermentation maceration
would not be recommended. Neither the vintage, nor the
foliar spray treatment, affected the SM% values signicantly.
The foliar spray resulted in a signicant increase in
berry skin thickness (Spsk) at all sampling dates. The harvest
date and the vintage did not inuence the skin thickness
signicantly. The skin hardness (Fsk) values were signicant
lower for the treated grapes in three cases (rst harvest date
in 2012, second and third harvest dates in 2013). Our results
show that the concentration of anthocyanins was higher in
the thicker skins and also in the case of lower skin hardness
(Fsk). This is the opposite of other ndings, where thinner
(Río Segade et al., 2011) and harder skins (Rolle et al., 2008;
2009) contained more anthocyanins. However, thicker and
softer skins may also contain more anthocyanins due to the
increased avonoid synthesis and higher berry skin/esh
ratio. The enhanced pigment accumulation due to the foliar
spray is also supported by Duo et al. (2014) and Lissarrague
et al. (2014). Berry texture parameters were strongly modied
by vintage effect, as seen before (Letaief et al., 2008a; Río
Segade et al., 2008). Young’s modulus of berry skin (Esk),

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
Enhancing Phenolic Maturity of Syrah
311
TABLE 4
Wine composition parameters.
Parameter Vintage Harvest date
2012-09-06 / 2013-09-12 2012-09-13 / 2013-09-19 2012-09-27 / 2013-10-03
Treatment
C LM C LM C LM
Alcohol (%v/v) 2012 14.58 ± 0.09aα 14.43 ± 0.20aα 15.08 ± 0.26aαβ 15.15 ± 0.21aβ 15.35 ± 0.33aβ 15.55 ± 0.31aβ
2013 11.28 ± 0.18aα 12.11 ± 0.62aαβ 11.87 ± 0.06aβ 11.62 ± 0.23aα 13.80 ± 0.50aγ 13.12 ± 0.26aβ
******
Titratable acidity (g/L) 2012 7.03 ± 0.06aα 6.00 ± 0.20bα 5.03 ± 0.06aβ 5.47 ± 0.31aα 5.87 ± 0.21aγ 5.63 ± 0.06aα
2013 8.33 ± 0.15aα 7.60 ± 0.10bα 7.63 ± 0.12aβ 7.00 ± 0.17bβ 6.67 ± 0.15aγ 6.97 ± 0.21aβ
******
pH 2012 3.33 ± 0.01aα 3.65 ± 0.05bα 3.72 ± 0.04aβ 3.81 ± 0.07aβ 3.86 ± 0.04aγ 3.69 ± 0.02bα
2013 3.02 ± 0.03aα 3.16 ± 0.01bα 3.15 ± 0.02aβ 3.07 ± 0.01bβ 3.11 ± 0.01aβ 3.12 ± 0.02aγ
******
Total polyphenols (mg/L) 2012 2562 ± 64aα 2708 ± 83aα 2944 ± 59aβ 2928 ± 68aβ 2782 ± 50aγ 2850 ± 69bαβ
2013 1045 ± 47aα 1035 ± 78aα 1025 ± 91aα 1117 ± 61aαβ 1304 ± 165aα 1260 ± 113aβ
******
Leuco-anthocyanins
(mg/L)
2012 1641 ± 42aα 1582 ± 105aα 1543 ± 39aαβ 1767 ± 111bα 1449 ± 43aβ 1770 ± 50bα
2013 1137 ± 103aα 1248 ± 89aα 1152 ± 41aα 1386 ± 168aαβ 1526 ± 102aβ 1626 ± 141aβ
* * * *
Catechins (mg/L) 2012 1517 ± 73aα 1184 ± 37bα 1747 ± 65aβ 1538 ± 109bβ 1371 ± 48aα 1421 ± 52aβ
2013 962 ± 85aα 916 ± 64aα 820 ± 33aα 997 ± 62bα 1048 ± 156aα 1072 ± 87aα
******
Anthocyanins (mg/L) 2012 740 ± 19aα 793 ± 31aα 736 ± 23aα 796 ± 13bα 688 ± 47aα 762 ± 43aα
2013 340 ± 56aα 406 ± 10aα 408 ± 9aα 463 ± 21bαβ 526 ± 39aβ 576 ± 51aβ
******
Color intensity (A420 + A520 + A620)2012 23.43 ± 0.86aα 23.61 ± 0.64aαβ 22.18 ± 0.48aα 24.04 ± 0.07bα 22.82 ± 0.14aα 24.47 ± 0.07bβ
2013 14.68 ± 2.33aα 20.49 ± 0.92bα 17.70 ± 0.18aα 20.16 ± 1.67aα 23.34 ± 0.88aβ 25.56 ± 1.75aβ
* * * *
Color hue (A420/A520)2012 0.60 ± 0.02aα 0.64 ± 0.02aα 0.63 ± 0.02aαβ 0.64 ± 0.01aα 0.65 ± 0.01aβ 0.63 ± 0.00aα
2013 0.39 ± 0.01aα 0.37 ± 0.01bα 0.35 ± 0.00aβ 0.34 ± 0.00bβ 0.34 ± 0.00aβ 0.34 ± 0.00aβ
******
HCl index 2012 4.83 ± 0.15aα 5.06 ± 3.16aα 6.53 ± 0.35aβ 12.99 ± 0.03bβ 9.50 ± 0.36aγ 11.16 ± 1.24aβ
2013 5.01 ± 0.53aα 6.14 ± 0.54aα 4.97 ± 0.73aα 4.34 ± 0.61aβ 4.43 ± 0.68aα 6.27 ± 0.14bα
******
Gelatine index 2012 46.91 ± 1.19aα 51.58 ± 0.51bα 52.32 ± 1.65aβ 52.50 ± 0.21aα 52.59 ± 0.91aβ 56.58 ± 0.36bβ
2013 26.40 ± 2.52aαβ 23.17 ± 1.85aαβ 23.13 ± 0.93aα 23.23 ± 0.35aα 18.20 ± 0.30aβ 18.90 ± 0.30bβ
******
Values marked with different Roman letters mean signicant differences between the treatments within the same year and same harvest date. Different Greek letters mean signicant differences between
harvest dates within the same year and same treatment. * means signicant differences between the years within the same treatments and harvest dates. For separation, Tukey’s test and the Games-Howell
post hoc test were used at p = 0.05. Each value represents the average ± standard error of three replicates. C = control, LM = foliar sprayed

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
312
Enhancing Phenolic Maturity of Syrah
TABLE 5
Resveratrol analysis of wines.
Parameter Vintage Harvest date
2012-09-06 / 2013-09-12 2012-09-13 / 2013-09-19 2012-09-27 / 2013-10-03
Treatment
C LM C LM C LM
Trans-resveratrol (mg/L) 2012 n.d. 0.10 ± 0.01α 0.83 ± 0.25aα 0.41 ± 0.01bβ 0.30 ± 0.10aα 0.23 ± 0.08aαβ
2013 n.d. 0.16 ± 0.14αβ 0.10 ± 0.12αn.d. 0.63 ± 0.10aβ 0.50 ± 0.11aβ
* * * *
Cis-resveratrol (mg/L) 2012 n.d. n.d. n.d. n.d. n.d. n.d.
2013 n.d. n.d. n.d. n.d. n.d. n.d.
Trans-piceid (mg/L) 2012 1.07 ± 0.06aα 1.39 ± 0.04bα 0.57 ± 0.06aβ 1.45 ± 0.05bα 0.50 ± 0.05aβ 0.55 ± 0.05aβ
2013 0.37 ± 0.28aα 0.46 ± 0.16aα 0.41 ± 0.07aα 0.12 ± 0.11bβ 0.47 ± 0.32aα 0.74 ± 0.05aα
* * * * *
Cis-piceid (mg/L) 2012 n.d. 0.93 ± 0.15αβ 1.20 ± 0.20aα 0.90 ± 0.00aα 0.87 ± 0.06aα 0.61 ± 0.07bβ
2013 0.41 ± 0.09aα 0.60 ± 0.34aα 0.25 ± 0.02aα 0.87 ± 0.19bαβ 1.05 ± 0.31aβ 1.63 ± 0.30aβ
* * * *
Σ (mg/L) 2012 1.07 ± 0.06aα 2.42 ± 0.18bα 2.60 ± 0.00aβ 2.76 ± 0.06aα 1.67 ± 0.20aγ 1.39 ± 0.17aβ
2013 0.78 ± 0.32aα 1.23 ± 0.26bα 0.73 ± 0.11aα 0.99 ± 0.10aα 2.14 ± 0.69aβ 2.87 ± 0.23bβ
* * * * *
Values marked with different Roman letters mean signicant differences between the treatments within the same year and same harvest date. Different Greek letters mean signicant differences between
harvest dates within the same year and same treatment. * means signicant differences between the years within the same treatments and harvest dates. For separation, Tukey’s test and the Games-Howell
post hoc test were used at p = 0.05. Each value represents the average ± standard error of three replicates. n.d. = not detectable, C = control, LM = foliar sprayed

S. Afr. J. Enol. Vitic., Vol. 36, No. 3, 2015
Enhancing Phenolic Maturity of Syrah
313
Brugger et al., 2006; Santamaria et al., 2011). In this way,
secondary metabolism is enhanced in the berries (Zhao et al.,
2005).
Overall, it seems that the impact of the foliar spray was
stronger in the earlier phases of the grape-ripening process.
As the ripening went forward the differences decreased
between the treatments, while remaining noticeable until the
end of the ripening.
CONCLUSION
We examined the impacts of the application of yeast
derivatives (LalVigne® MATURE, Lallemand Inc.) on
Syrah grape phenolic maturity as well as on wine phenolic
composition and concentration. The results from two
vintages indicate that its application led to more optimal
harvest conditions. In addition, a higher level of phenolic
maturity was achieved in both warm (2012) and cool (2013)
vintages. The application of this foliar spray results in
wines that are more balanced, and showing more avours
and complexity than the ones made from unsprayed vines.
Preliminary evidence was also obtained to suggest that
LalVigne® MATURE may help in cooler and less optimal
vintages by enhancing the ripening process, leading to wines
with greater oenological potential. Moreover, thicker grape
skins and accumulation of resveratrol in the early phases
could play an important role in plant protection.
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