## 2 Materials and Methods
### Volatile Compound Analysis  
Volatile compounds were extracted from berry samples using headspace-solid phase microextraction (HS-SPME). Skins and pulps were separated from seeds and ground into juice using a sterile mortar, where calcium chloride (CaCl\({}_{2}\), Sigma-Aldrich, St. Louis, MO, USA) was added to increase ionic strength. For headspace sampling, 8 mL of grape juice and 1.5 g NaCl was added in a 20 mL of SPME glass screw cap vial with 20 \(\upmu\)L of internal standard (4-methyl-2-pentanol; the final concentration was 20 \(\upmu\)g/L in the vial).  
Analyses were performed using an Agilent 7890B gas chromatograph coupled to an Agilent 5977A mass spectrometer (Agilent Technologies Inc., Santa Clara, CA, USA). Prior to injection, samples were pre-incubated at 40 \({}^{\circ}\)C for 10 min and stirred at 250 rpm. After agitation, a DVB/CAR/PDMS fiber was injected into the vial headspace for volatile absorption for 50 min. Volatiles were thermally desorbed for 5 min at 250 \({}^{\circ}\)C. Volatiles were separated with a 30 m \(\times\) 250 \(\upmu\)m \(\times\) 0.25 \(\upmu\)m DB-WAX column (Agilent Technologies Inc., Santa Clara, CA, USA). The oven-temperature program was as follows: hold at 50 \({}^{\circ}\)C for 1 min, then heat up to 220 \({}^{\circ}\)C at a rate of 1 \({}^{\circ}\)C, and hold at this temperature for 5 min. The interface temperature of mass spectrometry was 280 \({}^{\circ}\)C; the ion source temperature was 230 \({}^{\circ}\)C; the ionization mode was the electron impact ion source; the ion energy was 70 eV; and the mass scanning range was 19-350 \((m/z)\). The column flow rate was 0.8 mL/min, and different compounds were separated via programmed heating. The carrier gas was helium.  
The identification of VOCs was carried out using MSD Chemstation (E.15.0.0.498, Agilent Technologies Inc., USA) according to [PERSON] et al. [5]. Dominant ions were used to select peaks, and only VOCs peaks with signal-to-noise ratios greater than 10:1 were considered for data quantification. Identification was achieved by comparing the mass spectra with those of authentic standards when available, and with MS from the data system library (Nist2014, Agilent Technologies Inc. USA) and previous published retention indices.  
The calibration curves were constructed according to [PERSON] et al. [5]. Seven concentrations of the mix standard solutions were injected in triplicate. Standard calibration curves of 25 compounds (1-propanol, 1-heptanol, 1-pentanol, 1-nonanol, 2-octanol, hexanal, 2-hexanal, 2-octanone, acetic acid, 2-methyl-1-propanol, 2-ethyl-1-hexanol, benzyl alcohol,acetic acid, hexyl ester, acetic acid, 2-phenylethyl ester, acetic acid, methyl ester, hexanoic acid, ethyl ester, geraniol, linalool, citral, D-limonene, and \(\alpha\)-terpineol) were constructed. Independent stock solutions (in ethanol) were prepared for each standard. Standard solutions of the compounds were prepared by diluting the original stock solution of mixtures with simulated wine solution in order to obtain a range of concentrations (0-500 ug/mL). 4-methyl-2-pentanol was used as the internal standard (IS). Concentrations were calculated using the calibration curves of the available standard with the closest chemical structure. Semi-quantification was carried out for the compounds for which standards were not available; all reagents and standards were purchased from Sigma-Aldrich (St Louis, MO, USA).