Phenylethyl acetate

All the pure standards of volatile organic compounds (VOC) used in this manuscript were bought from Sigma-Aldrich (Steinheim, Germany): ethyl acetate (99.9%), hexanal (98%), 2-methyl-1-propanol (>99.5%), 1-butanol (99.9%), (E)-2-hexanal (98%), 1-pentanol (>99%), hexyl acetate (99%), 1-hexanol (>99.5%), cis-3-hexen-1-ol (98%), ethyl octanoate (>98%), 1-heptanol (>99.5%), linalool (>97%), isobutyric acid (99%), butyric acid (>99%), isovaleric acid (99%), geranyl acetate (>97%), β-citronellol (95%), nerol (98%), phenyl ethyl acetate (98%), β-damascenone (>90%), hexanoic acid (>99%), 2-phenyl ethanol (>99%), and β-ionone (>95%).

Apples (Malus domestica ‘Jonathan’, Csány 1) were collected beside the city of Székesfehérvár, located in central Hungary, in September 2019, and were transported to the laboratory for subsequent analysis. The Jonathan apple is a classic American variety, medium-sized apple, and widely regarded as one of the best flavored, with a good sweet/sharp balance. The Viniflora Concerto^TM (L. thermotolerans) and Melody^TM (mixed culture of T. delbrueckii, L. thermotolerans, and S. cerevisiae) starter cultures were obtained from Chr. Hansen A/S (Hoersholm, Denmark), while the Biodiva^TM Level 2 (Torulaspora delbrueckii TD291) and Uvaferm 228 (S. cerevisiae) of Lallemand Inc. (Montréal, QC, Canada) dry yeasts were purchased from Kokoferm Ltd. (Gyöngyös, Hungary). Standards (glucose, fructose, saccharose, acetic acid, lactic acid, succinic acid, acetaldehyde, methanol, isoamyl alcohol, 1-propanol, 1-butanol, 2-butanol, 2-phenylethanol, 1-hexanol, 2-methyl-1-butanol, trans-3-hexen-1-ol, cis-2-hexen-1-ol, benzyl alcohol, ethyl acetate, propyl acetate, ethyl hexanoate, ethyl butyrate, isoamyl acetate, phenylethyl acetate, diethyl succinate, ethyl octanoate, ethyl benzoate, ethyl formate, linalool), and all chemicals of analytical grade were obtained from Sigma-Aldrich (Steinheim, Germany).

The fermented tobacco leaves from the Dominican Republic, Brazil, Indonesia, and China were collected and provided by China Tobacco Sichuan Industrial Co., Ltd. (Sichuan, China). Potato dextrose agar (PDA), potato dextrose broth (PDB), and yeast extract peptone dextrose agar (YPD) medium were purchased from Solarbio Technology Co., Ltd. (Beijing, China). Ampicillin sodium was purchased from Sangon Biotech Co., Ltd. (Shanghai, China). The fungal DNA kit was purchased from Tiangen Biotech Co., Ltd. (Beijing, China). High-Performance Liquid Chromatography (HPLC) grade reagents used for chromatography were obtained from Thermo Fisher Scientific (Waltham, MA, United States). Phenylethyl acetate was purchased from Sigma-Aldrich Co. Ltd. (St. Louis, MO, United States). The QuEChERS extraction kit (Kit contents: 4 g MgSO₄, 1 g NaCl, 1 g NaCitrate, 0.5 g disodium citrate sesquihydrate, 50 mL tubes with ceramic homogenizers) was purchased from Agilent (Santa Clara, CA, United States).

1,4-Cineole (98%), 1-decanol (99.9%), 1-hexanol (99.9%), 1-octanol (≥99%), 2-heptanone (99%), 2-nonanone (97%), 2-undecanone (97%), 3-hexen-1-ol (98%), 5-methyl-2-furfural, benzaldehyde (≥99.5%), camphor (99%), decanal (95%), diethyl succinate (≥99%), ethyl 2-methylbutanoate (99%), ethyl butanoate (99%), ethyl decanoate (≥98%), ethyl heptanoate (≥98%), ethyl hexanoate (99%), ethyl isobutanoate (≥98%), ethyl isovalerate (98%), ethyl nonanoate (≥98%), ethyl octanoate (99%), eucalyptol (99%), furfural (99%), hexyl acetate (98%), isoamyl acetate (≥99%), isoamyl alcohol (98%), limonene (99%), linalool oxide (97%), nonanal (≥95%), octanal (≥98%), phenylacetaldehyde (90%), phenylethyl acetate (99%), phenylethyl alcohol (99%), tartaric acid (≥99.5%), α-pinene (99%)), β-cyclocitral (90%), β-damascenone (≥98%), α-ionone (85%), and β-linalool (80%) were supplied by Sigma-Aldrich (Madrid, Spain). Ethanol (99.9%) was purchased from ERBA Reagents (Val de Reuil, France).