Dataset of concentrations of free terpenes at different phenological stages in Vitis vinifera L. Shiraz, Cabernet Sauvignon, Riesling, Chardonnay and Pinot Gris

Five Vitis vinifera L. cultivars Shiraz, Cabernet Sauvignon, Riesling, Chardonnay and Pinot Gris at different E-L development stages were harvested in two experimental vintages. Temperature and rainfall data of the growing period were obtained from the Australian Government Bureau of Meteorology. Free terpene concentrations of all harvested grape samples were analysed using HS-SPME-GC-MS. One-way ANNOVA was performed to evaluate the significance of changes in terpene concentrations at different maturation stages. More analysis of the data is provided in “Free terpene evolution during the berry maturation of five Vitis vinifera L. cultivars” [1].


Data
This present data provide supplementary information to our previous work [1]. Total monoterpene, norisoprenoid and sesquiterpene concentrations at E-L 31, 33, 34, 35 and 38 of each variety in two vintages are plotted in Fig. 1. Temperature and rainfall information of vintages 2016 and 2017 was obtained from the Australian Government Bureau of Meteorology (nearest weather station: Ararat Prison Station, BoM ID: 089085, 15.5 km northwest to the experimental vineyard) and summarized in Table 1. Information of growing degree days (GDD) of each sample collection day is provided in Table 2. Compound identification based on comparison of retention indices and mass spectra are summarized in Table 3 and  Table 4, respectively. Concentrations of different classes of free terpenes and total monoterpene and total sesquiterpene in different grape cultivars at different developmental stages are shown in Tables 5e9.

Experimental design, materials and methods
Wine grape samples were harvested from a commercial vineyard in the Grampians wine region in Victoria, Australia. In two experimental vintages, vertical shoot positioned (VSP) trellis and drip irrigation systems were applied in the vineyard without significant pest or disease pressure detected. In vintage 2016, sample collection started from 18 December 2015 and continued in two-week intervals until commercial harvest. Matured Chardonnay and Pinot Gris were collected on 13 February 2016, while Shiraz, Cabernet Sauvignon and Riesling were collected on 14 March 2016. In vintage 2017, samples were collected fortnightly from 09 January 2017 due to delayed fruit-setting. The last batches of Riesling, Chardonnay and Pinot Gris were harvested on 20 March 2017 while Shiraz and Cabernet Sauvignon were on 18 April 2017. For each cultivar, grape brunches in triplicate were collected randomly from different positions of randomly selected grapevines (n > 30 for each cultivar). Samples were transported to the laboratory on dry ice and stored at À20 C before analysis.
Specifications Table   Subject area Phytochemistry, Plant Science More specific subject area Aroma chemistry of wine grapes Type of data Figure Value of the data Our previous data [2] showed changes in terpene accumulation during ripening of Shiraz wine grapes. The datasets here provide information about free terpene concentrations at different development stages of Vitis vinifera L. cv. Shiraz, Cabernet Sauvignon, Riesling, Chardonnay and Pinot Gris. All grape cultivars are located within the same vineyard, which minimizes site variations of environmental and geography factors, which may alter terpene production amongst different cultivars. These datasets could provide new insights into the free terpene evolution of five economically important wine grape varieties. Further studies could be conducted to investigate the genetic or metabolic differences among cultivars leading to the variations in terpene production. Terpene analysis was conducted on an Agilent 6890 GC coupled with an Agilent 5973 MSD (Agilent Technologies, Santa Clara, CA) and an Agilent PAL multipurpose sampler connected to the GC. The HS-SPME-GC-MS analysis was conducted based on our previous data with some modifications [3].
Briefly, after destemming, grape berries were frozen with liquid nitrogen and then powdered with a stainless steel grinder. Five g of the sample powder was extracted with 30 mL of a pH 3.2 extraction solution, which consisted of 5 g/L polyvinylpolypyrrolidone (PVPP), 0.5 g/L tartaric acid and 0.5 g/L of sodium sulfite, at room temperature for 24 h with a stirring rate of 100 rpm. A 0.45 mm nylon syringe filter was used to filter the mixture and then 5 mL of the supernatant was mixed with 1 g of sodium chloride and 20 mL of 2 mg/L b-cedrene internal standard in a 20 mL GC vial. The headspace in the GC vial was extracted by using a 65 mm DPMS/DVB SPME fibre (Supelco, Bellefonte, PA) for 60 min with agitation at 45 C in an agitator mounted on the Agilent PAL multipurpose sampler.
Chromatographic separation was achieved on a J&W DВ-5ms capillary column (Agilent Technologies; 30 m Â 0.25 mm Â 0.25 mm). Purified helium was used as the carrier gas at a constant flow rate of 1.0 mL/min. GC conditions were based on our previous protocol with slight modifications . Compounds adsorbed on the SPME fibre were desorbed under pulsed splitless mode and the mass spectrometer was operated in scan/sim mode under positive electron ionization (EI) mode at 70 eV, with a scan range from m/z 35 to 280. As sesquiterpenes exist in trace amounts, simultaneous selected ion monitoring (SIM) mode was used to record common terpene ions: m/z 105, 133, 147, 161, and 204 to facilitate locating target compounds. Quantification of terpenes was based on the target ion peak areas.  A mixed alkane standard (C7eC30) was used to determine the retention index (RI; I) for each peak. Terpene identification was carried out by matching the mass spectrum and I value in the terpenoids library using MassFinder 4 software (Hochmuth Scientific Consulting, Hamburg, Germany). Although I values in the terpenoids library are based on a J&W DB1 column while in this present data a DB-5 column was used, these two nonpolar columns have very close I profiles as shown in previous data [4]. Therefore, I values from the terpenoids library are reliable in facilitating the tentative identification in the present data. Peak integration was then conducted with the Agilent ChemStation software based on the responses of target ions. Calculated and reference RI are summarized in Table 3. Mass spectra of semi-quantified terpenes are provided in Table 4. Quantification of each terpene was performed against calibration curves constructed by a series of standards including, a-terpineol, linalool, geraniol, geranylacetone. a-Terpinene, cymene (m-and p-), 1,8-cineol, (E)-b-ocimene, g-terpinene, terpinolene, p-cymenene and hotrienol were semi-quantified using a linalool standard. All sesquiterpenoids and norisoprenoids were semi-quantified with the internal standard b-cedrene and expressed as equivalent concentrations.
Significant (p < 0.05) differences in terpene concentrations at different development stages of each grape cultivar were analysed by one-way ANOVA using SPSS 24 (SPSS Inc., Chicago, IL).  [4]. b The first of the target ions was used as quantifier and others were qualifiers. Table 4 Comparisons between reference terpenoid mass spectra from the terpenoids library (upper frame) and for an experimental peak in a representative sample (lower frame).

Terpenoid Mass spectrum
Monoterpenoids a-Terpinene                  Notes: Linalool, a-terpineol, geraniol and geranylacetone were quantified using their pure standard compounds. a-terpinene, cymene (m-and p-), 1,8-cineol, (E)-b-ocimene, g-terpinene, terpinolene, p-cymenene and hotrienol were semi-quantified using a linalool standard. All monoterpenes are expressed at mg/g grape sample. All sesquiterpenoids and norisoprenoids were semi-quantified with the internal standard b-cedrene and expressed as equivalent concentrations of the internal standard at mg/kg grape sample. ND: not detected. Values labelled with the same lower case letter in the same row are not significantly (p < 0.05) different. Raw data of the table are provide in data file 1. Notes: Linalool, a-terpineol, geraniol and geranylacetone were quantified using their pure standard compounds. a-terpinene, cymene (m-and p-), 1,8-cineol, (E)-b-ocimene, g-terpinene, terpinolene, p-cymenene and hotrienol were semi-quantified using a linalool standard. All monoterpenes are expressed at mg/g grape sample. All sesquiterpenoids and norisoprenoids were semi-quantified with the internal standard b-cedrene and expressed as equivalent concentrations of the internal standard at mg/kg grape sample. ND: not detected. Values labelled with the same lower case letter in the same row are not significantly (p < 0.05) different. Raw data of the table are provide in data file 1.  g-Eudesmol 0.02 ± 0a 0.01 ± 0b 0.02 ± 0a 0.01 ± 0b ND Cubenol 0.05 ± 0.01a 0.04 ± 0.01a 0.03 ± 0ab 0.02 ± 0.01b 0.01±0b Cadalene 0.04 ± 0.01b 0.08 ± 0.02a 0.08 ± 0.01a 0.07 ± 0.01a 0.04±0b Total 2.99 ± 0.36ab 2.1 ± 0.3abc 3.32 ± 0.99a 1.75 ± 0.14bc 1.25 ± 0.07c Notes: Linalool, a-terpineol, geraniol and geranylacetone were quantified using their pure standard compounds. a-terpinene, cymene (m-and p-), 1,8-cineol, (E)-b-ocimene, g-terpinene, terpinolene, p-cymenene and hotrienol were semi-quantified using a linalool standard. All monoterpenes are expressed at mg/g grape sample. All sesquiterpenoids and norisoprenoids were semiquantified with the internal standard b-cedrene and expressed as equivalent concentrations of the internal standard at mg/kg grape sample. ND: not detected. Values labelled with the same lower case letter in the same row are not significantly (p < 0.05) different. Raw data of the table are provide in data file 1.  Table 9 Terpene concentrations at different developmental stages of Pinot Gris in the two experimental vintages.