# Use of Dairy and Plant-Derived Lactobacillus as Starters for Cherry Juice Fermentation
## 2 Materials and Methods
### Sugars and Organic Acid Analysis  
Sugars and organic acids were analyzed after fermentation and storage, both for fermented juices and for controls. The method reported by [PERSON] et al. (2018), with slight modifications, was applied. Briefly, 10 \(\upmu\)L of samples was added to 1 mL of a solution containing two internal standards (turanose and glutaratic acid 500 \(\upmu\)g/mL each), dried under vacuum and dissolved with 500 \(\upmu\)L of dimethylformamide. Subsequently, silylation was carried out adding 400 \(\upmu\)L of hexamethyldisilazane and 200 \(\upmu\)L of trimethylchlorosilane to the samples and heating for 30 min at 70 \({}^{\circ}\)C. Samples were analyzed by a Thermo Scientific Trace 1300 gas chromatograph coupled to a Thermo Scientific ISQ single quadrupole mass spectrometer equipped with an electronic impact (EI) source on a BP5 MS capillary column (30 m \(\times\) 0.25 mm, with 0.25 \(\upmu\)m film thickness, SGE Analytical Science, Milan, Italy). Chromatographic conditions were the following: initial oven temperature, 60 \({}^{\circ}\)C, then increase of  
\begin{table}
\begin{tabular}{c c c} \hline
**Species** & **Strain** & **Origin** \\ \hline \multirow{4}{*}{_L. plantarum_} & POMI \({}^{\ast}\) & Tomato (plant) \\  & C1 \({}^{\ast}\) & Carrot (plant) \\  & 1 LE1 \({}^{\ast}\) & Pineapple (plant) \\  & 285 \({}^{\ast\ast}\) & Minas cheese (dairy) \\ \hline \multirow{4}{*}{_L. rhamns_} & 2178 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\  & 2140 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\  & 2360 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\  & 1473 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\  & 1019 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\ \hline \multirow{4}{*}{_L. casei_} & 2246 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\  & 2306 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\ \cline{1-1}  & 2057 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\ \cline{1-1}  & 2107 \({}^{\ast\ast}\) & Parmigiano Reggiano cheese (dairy) \\ \hline \multicolumn{2}{c}{_L. paracasei_} & 4186 \({}^{\ast\ast}\) & Pecorino cheese (dairy) \\ \hline \end{tabular} \({}^{\ast}\) Department of Soil, Plant and Food Science, University of Bari, Italy. \({}^{\ast\ast}\) Department of Food and Drug, University of Parma, Italy.  
\end{table}
Table 1: Microbial strains used in the study and their origin.  
20 \({}^{\circ}\)C/min up to 280 \({}^{\circ}\)C; carrier gas, (flow rate, 1 mL/min). Temperature of the transfer line was maintained at 280 \({}^{\circ}\)C, while the ion source was set at 230 \({}^{\circ}\)C. The acquisition mode was full scan (m/z: 40-550). Signals were identified on the basis of their mass spectra compared with those present in the instrument library (NIST 14). In addition, once the glucidic and organic acid fractions were recognized, proper analytical standards were used in order to confirm the identifications. The semi quantification of all detected gas-chromatographic signals was performed on the basis of the use of two internal standards: turnaose for sugar quantification and glutaratic acid for organic acid quantification. For each identified compound, the Response Factor (RF) was calculated and the values range between 0.8-1.2.