Benzoic acid

For identification and quantitation of aroma compounds, the following authentic flavor standards were purchased from Macklin Biochemical Technology Co., Ltd., Shanghai, China: methyl valerate (99%), isovaleraldehyde (98%), furfuryl mercaptan (98%), heptanal (97%), hexanal (99%) and 2-butylfuran (98%). Benzyl alcohol (AR, 99%), 1-octen-3-one (98%), 1-octen-3-ol (98%), methyl palmitate (AR, 97%) and benzoic acid (99%) were purchased from Yuanye Bio-Technology Co., Ltd., Shanghai, China. Phenylacetaldehyde (95%) and benzaldehyde (AR, ≥98.5%) were obtained from Sinopharm Chemical Reagent Co., Ltd., Beijing, China. The internal standard, 1-decanol (GC, ≥99.5%), was purchased from Aladdin Biochemical Technology Co., Ltd., Shanghai, China.

Gallic acid, p-hydroxybenzoic acid, ferulic acid, trans-cinnamic acid, p-coumaric acid, benzoic acid, ellagic acid, protocatechuic acid, sinapic acid, caffeic acid, quercetin, rutin, taxifolin, isoquercitrin, catechin, gallocatechin, epicatechin, vitexin, genistin, daidzin, phloroglucinol, quinic acid, and 3,4-dihdyroxyphenylaceticacid were obtained from Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Procyanidin B1, procyanidin B2, and kaempferol-3-O-rutinoside were obtained from Chengdu Pusi Biotechnology Co., Ltd. (Chengdu, China). 2,20-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,4,6tri(pyridin-2-yl)-1,3,5-triazine (TPTZ), (±)-6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), fluorescein, 3′,6′-dihydroxyspiro [isobenzofuran-1 (3 H),9′-(9 H) xanthene]-3-one (FL), 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH), and EDTA-2Na were purchased from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). Thermo Fisher Scientific (Waltham, MA, USA) provided the methanol (HPLC quality), formic acid (99.9%, LC-MS grade), and acetonitrile (LC-MS grade). Cellulase (T richoderma Vride G, 400 u/mg), hemicellulase (Aspergillus niger, 20 u/mg), and pectinase (Aspergillus niger, 500 u/mg) were obtained from Yuanye Bio-Technology Co., Ltd. (Shanghai, China).