1 octen 3 one

Analytical-grade chemicals and reagents for preparing standard solutions for GC-MS analysis were used without further purification. Standard 1-octen-3-one (96%), 1-octen-3-ol (≥98%), 3-octanone (≥98%), benzaldehyde (≥99.5%), trans-2-hexen-1-ol (96%), benzyl alcohol (99%+), 1,5-dimethyl naphthalene (98%), 3-methyl-1-butanol (99%+), 1,5-dimethyltetralin (≥90%), phenylethyl alcohol (≥99%), 4-methyl-2-pentanol (98%), glucose (≥99.5%), fructose (≥99%), tartaric acid (99%), naphthalene-d8 (99 atom% D, ≥98% (CP)), 3-octanol (99%), 2-octanol (≥99.5%), zinc nitrate hexahydrate (98%), 2-methylimidazole (98%), and glass wool were purchased from Sigma-Aldrich (Sydney, NSW, Australia). Hexanal (98%), 1-hexanol (99%), menthol (HPLC), and N,N-dimethylformamide (DMF) (99%) were purchased from Alfa Aesar (Scoresby, VIC, Australia). Hexanal-d12 (98.5 atom % D) and 2,4,6-tribromoanisol-d5 (99 atom % D) were purchased from CDN Isotopes (Pointe-Claire, Quebec, Canada). Milli-Q™ water (18 MΩ·cm) was collected through a Millipore™ water purification system (Merk, Bayswater, VIC, Australia). Synthetical grape juice was made using 100 g glucose, 100 g fructose, and 4 g tartaric acid. All solutions were prepared in Milli-Q™ water, with the pH adjusted to 7.0.

Isobutyl ITC 97%, 4-pentenyl ITC 95% and sec-butyl ITC 97% were purchased from ABCR (Karlsruhe, Germany), 3-sec-butyl-2-methoxypyrazine from Acros Organics (Geel, Belgium), (3S,3aS,7aR)-wine lactone >95% from Aromalab (Freising, Germany), 2-(methylthio)ethyl ITC >96% from FCH Group (Chernigiv, Ukraine), butanoic acid ≥99% from Fluka (Steinheim, Germany), (Z)-3-hexenal 50% from SAFC (Steinheim, Germany) and 3-methylbutyl ITC >98% from Santa Cruz Biotechnology (Heidelberg, Germany). Acetic acid >99%, AITC 95%, p-anisaldehyde 98%, benzyl ITC 98%, 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolone) ≥97%, 3-isobutyl-2-methoxypyrazine ≥99%, 3-isopropyl-2-methoxypyrazine 99%, 2-methylbutanoic acid 98%, 3-methylbutanoic acid 99%, skatole 98%, 3-(methylthio)propanal 98%, 3-(methylthio)propyl ITC 98%, 1-octen-3-one 50%, 2-phenylacetaldehyde 90% and PEITC >99% were purchased from Sigma-Aldrich (Steinheim, Germany) and 3-butenyl ITC 95% from TCI Europe (Eschborn, Germany). CETP was synthesized as described in our previous study (Kroener and Buettner, 2017 (link)).
Dichloromethane (DCM), which was freshly distilled for purification prior to use, and anhydrous sodium sulfate were purchased from VWR International GmbH (Darmstadt, Germany).

Fatty acid methyl esters of palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3), C₃-C₂₅ of n-alkanes, 2,3-butanedione, hexanal, (E)-2-hexenal, 1-octen-3-ol, 1-octen-3-one, 2-heptanone, (E)-2-octenal, and 1-hexanol were purchased from Sigma (St. Louis, MO, USA). 3-Octen-2-one, 2-n-butyl furan, heptanal, and (E)-2-nonenal were purchased from TCI (Tokyo, Japan). Benzeneacetaldehyde, 2,3-butanediol, 3-methyl-2-butanone, and benzaldehyde were obtained from RHAWN reagent corporation (Shanghai, China). 1-Penten-3-one and 3-methyl-1-butanol were purchased from Aladdin reagent corporation (Shanghai, China). 2-Pentyl-furan was purchased from J&K Scientific Ltd. (Beijing, China). Heptenal was purchased from Accustandard (New Haven, CT, USA). Diethyl ether, n-hexane, and petroleum ether were purchased from Yongda chemical reagent co. Ltd. (Tianjin, China). Boron trifluoride-methanol solution (14% BF3·methanol) was purchased from CNW technologies (Dusseldorf, Germany). Milli-Q water was used in this study (Millipore, Billerica, MA, USA).

Diethyl ether (99.5%) was purchased from Fisher Scientific, UK. Allyl isothiocyanate (95%), (Z)-3-hexen-1-ol (98%), 1-octen-3-one (96%), nonanal (95%), (E)-anethol (99%), (S)-bornyl acetate (95%), (E)-caryophyllene (98%), pentadecane (>99%) were from Sigma-Aldrich, UK.

Dichloromethane, anhydrous sodium sulfate, n-hexane were purchased from Yifengtiancheng Scientific Instruments Co. Ltd. (Beijing, China); n-Alkanes (C7~C30) and 4-methyl-2-pentanol were purchased from Sigma-Aldrich (St Louis, MO, USA); Nitrogen (99.9992% purity) was purchased from Beijing Haipu Beifen Gas Industry Co. Ltd. (Beijing, China).
Standards of volatile compounds, hexanal, trans-2-hexenal, (Z)-3-hexenyl acetate, trans-2-heptenal, 6-methyl-5-hepten-2-one, (Z)-3-hexen-1-ol, acetic acid, 2-octanone, and 1-octen-3-one were purchased from Sigma-Aldrich Co. Ltd. (Santa Clara, CA, USA).

The following reference compounds: acetic acid, acetoin, 2-methylbutanal, 2-methylpyrazine, 2,5-dimethylpyrazine, 2-furanmethanethiol, 2-acetyl-1-pyrroline, benzaldehyde, 1-octen-3-one, octanal, linalool, 2-acetylthiazole, 2-acetylpyridine, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 2-methoxyphenol, 3-hydroxy-4,5-dimethyl-2(5H)-furanone, hexadecanol, octadecanal, 2.3-pentanedione, butanoic acid, β-iso-methyl ionone, β-ionone, were from Sigma-Aldrich (St. Louis MO). Stock standard solutions 10³ or 10⁴ µg mL⁻¹ of each compound was prepared as described earlier [21 (link)].