α farnesene

All VOC standards were purchased from Sigma-Aldrich (St. Louis, MO, United States): 1-penten-3-ol, 1-penten-3-one, 3-pentanone, α-caryophyllene, α-farnesene, α-pinene, β-caryophyllene, β-farnesene, β-ionone, benzaldehyde, cis-3-hexen-1-ol, cis-3-hexenyl acetate, eugenol, hexyl acetate, jasmone, limonene, linalool, methyl jasmonate, methyl salicylate, ocimene, trans-2-hexen-1-al. All VOC standards were diluted in 100% methanol.

Five-year-old tea plants of Camellia sinensis cv. “Shu Cha Zao” grown at the experimental farm of Anhui Agricultural University in Hefei, China, were used in this study. Standards of geranyl diphosphate (GDP), farnesyl diphosphate (FDP), β-myrcene, β-ocimene, linalool, geraniol, α-citral, β-citral, methyl geranate, nerol, D-limonene, trans-linalool oxide (furanoid), neryl acetate, L-terpineol, α-terpinen, geranyl acetone, thymol, (Z)-nerolidol, α-farnesene, β-farnesene, (E)-nerolidol, humulene, α-ionone, β-ionone, (E)-γ-bisabolene, cadinol and caryophyllene were purchased from Sigma-Aldrich (St. Louis, MO, USA).

The following synthetic standards were purchased from Sigma-Aldrich and tested in the concentration 5×10^-3 µg µL^-1: methyl (E)-hex-3-enoate, methyl (E)-hex-2-enoate, 6-methylhept-5-en-2-one, ethyl hexanoate, ethyl (E)-hex-3-enoate, methyl (E)-oct-2-enoate, geranyl acetone, (E,E)-α-farnesene, methyl (2E,6E)-farnesoate, linalool, (E)-non-2-enal, (Z)-non-3-enol, and (Z)-non-2-enol. (Z)-Non-3-enal and (Z)-non-2-enal were prepared in our laboratory from the corresponding alcohols (Hazzard 1973 ). The purchased and synthesised chemicals were of analytical grade purity.

The fermentation broth was centrifuged at 12,000 rpm for 10 min. Then, the upper layer of n-dodecane liquid was filtered. A total of 100 μL of samples in n-dodecane phase were taken out and diluted ten times, and then a small amount of anhydrous copper sulfate was added to remove residual water. Quantification was performed using Shimadzu GC-2010 plus, a gas chromatograph equipped with a flame ionization detector (FID). The detection method of α-farnesene is as described by Liu et al. [3 (link)]. The standard α-farnesene, antibiotics and chemicals were purchased from Sigma (Sigma-Aldrich, Burlington, MA, USA).

Two cultivars of mandarin, Afourer (A) and Richard Special (RS), were kindly donated by the First Fresh (NZ) Ltd. (Gisborne, New Zealand). Two carrier materials for spray drying, maltodextrin (MD: 10–13 DE) and gum arabic (GA), were purchased from Ingredion Ltd. (Singapore) and Hawkins Watts Ltd. (Auckland, New Zealand), respectively. The chemicals were sources, as below: 2,4,6-Tripyridyl-s-Triazine (TPTZ), gallic acid, and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), were purchased from Sigma–Aldrich (Auckland, New Zealand); 2,2-azino-bis-3-ethylbenzothiazaoline-6-sulfonic acid (ABTS) was purchased from Abcam Inc. (Melbourne, VIC, Australia); formic acid was obtained from EMD Millipore Corporation (Billerica, MA, USA).
Authentic standards, including chlorogenic acid (≥95%), ferulic acid (≥99%), p-coumaric acid (≥98%), vanillic acid (≥97%), α-pinene (≥98%), β-myrcene (≥90%), d-limonene (≥97%), γ-terpinene (≥95%), α-terpineol (≥95%), β-famesene (≥99%), linalool (≥97%), α-farnesene (≥99%), nerol (≥97%), hexanal (≥98%), and 3-octanol (≥98.5%), were purchased from Sigma–Aldrich (Auckland, New Zealand). Hesperidin (HPLC grade) and p-hydroxybenzoic acid (HPLC grade, ≥99%) were purchased from Abcam Inc. (Melbourne, VIC, Australia).