C7 c40n alkane standard

Black soybeans were purchased from NongHyup (Yeoryang, South Korea) and stored at 5 ℃ before the preparation of soybean milk. For the analysis of volatile flavor compounds, C₇ − C₄₀n-alkane standard and a 50/30 μm divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS) solid-phase microextraction (SPME) fiber were purchased from Supelco (Bellefonte, PA, USA). Butyrophenone was purchased from Sigma-Aldrich Chemical Co. (St. Louis, MO, USA) as an internal standard. For the analysis of isoflavones, daidzein, genestein, glycitein, daidzin, and genistin (Sigma-Aldrich Chemical Co.) were used as standards. HPLC-grade water, acetonitrile, acetic acid, and methanol were purchased from J.T. Baker (Philipsburg, NJ, USA). All chemicals and reagents used in the study were of analytical grade.

Green coffee beans (C. arabica Sitio Chapada from Brazil and C. robusta from Vietnam) were purchased from Trini Coffee (Goyang, Korea). DL-Malic acid (≥98%), citric acid (≥98%), L-(+)-tartaric acid (≥99.5%), and succinic acid (≥99%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Green coffee beans and organic acid powder were stored at room temperature.
For the analysis of volatile flavor compounds, C7 − C40 n-alkane standard and a divinylbenzene/Carboxen/Polydimethylsiloxane (50 μm DVB/CAR/PDMS) solid-phase microextraction (SPME) fiber were purchased from Supelco, Inc. (Bellefonte, PA, USA). Hexane, high-performance liquid chromatography (HPLC)-grade water, and HPLC-grade ethyl acetate were purchased from J.T. Baker (Philipsburg, NJ, USA). Sodium chloride (NaCl) was purchased from Samchun (Seoul, Korea). Quinoxaline, 2-methyl pyrazine, 2,5-dimethyl pyrazine, 2,6-dimethyl pyrazine, ethyl pyrazine, 2-ethyl-6-methyl pyrazine, furfural, 2-acetyl furan, furfuryl acetate, 5-methyl furfural, and furfuryl alcohol were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan).
For the analysis of α-DCs, MGO (purity 40%), DA (purity 97%), o-phenylenediamine, and 1-methylpyrazole were purchased from Sigma-Aldrich. GO (purity 39%) was purchased from Tokyo Chemical Industry Co., Ltd. HPLC-grade water and HPLC-grade ethyl acetate were purchased from J.T. Baker.