title: Change in Flavonoid Composition and Antioxidative Activity during Fermentation of Onion (Allium cepa L.) by Leuconostoc mesenteroides with Different Salt Concentrations.
abstract: The aim of this study is to investigate the change in flavonoid composition and antioxidative activity during fermentation of onion (Allium cepa L.) by Leuconostoc mesenteroides with different NaCl concentrations. In order to qualify and quantify the flavonoids during fermentation of onion, 7 flavonoids, [quercetin 3,7-O-β-d-diglucopyranoside (Q3,7G), quercetin 3,4'-O-β-d-diglucopyranoside (Q3,4'G), quercetin 3-O-β-d-glucopyranoside (Q3G), quercetin 4'-O-β-d-glucopyranoside (Q4'G), isorhamnetin 3-O-β-d-glucopyranoside (IR3G), quercetin (Q), and isorhamnetin (IR)], were isolated and identified from onion. During fermentation, the contents of flavonoid glucosides (Q3,7G, Q3,4'G, Q3G, Q4'G, and IR3G) gradually decreased, whereas the contents of flavonoid aglycones (Q, IR) gradually increased. Decline rates of the flavonoid glucosides increased with the addition of L. mesenteroides. Furthermore, the activity of β-glucosidase, which is produced by L. mesenteroides, is dose-dependently inhibited with different NaCl concentrations during fermentation. The presence of L. mesenteroides enhanced the antioxidative activity of onion as demonstrated using the 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and reducing power assays. The enhancement of antioxidative activity was considered because the content of flavonoid aglycones increased during fermentation. However, the addition of NaCl may decrease the antioxidative activity; we surmise that this phenomenon occurs because of the inhibition of β-glucosidase by NaCl. Therefore, we conclude that the addition of NaCl may be useful for the regulation of antioxidative activity via the control of β-glucosidase action, during the fermentation of flavonoid glucoside-rich foods.
authors.affiliation: Authors are with Dept. of Food Science and Technology, Functional Food Research Center, and BK21 Plus Program, Chonnam National Univ, 77 Yongbongro, Gwangju, 61186, South Korea.
authors.forename: Yu Geon
authors.initials: YG
authors.lastname: Lee
authors.affiliation: Authors are with Dept. of Food Science and Technology, Functional Food Research Center, and BK21 Plus Program, Chonnam National Univ, 77 Yongbongro, Gwangju, 61186, South Korea.
authors.forename: Jeong-Yong
authors.initials: JY
authors.lastname: Cho
authors.affiliation: Authors are with Dept. of Food Science and Technology, Functional Food Research Center, and BK21 Plus Program, Chonnam National Univ, 77 Yongbongro, Gwangju, 61186, South Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Authors are with Dept. of Food Science and Technology, Functional Food Research Center, and BK21 Plus Program, Chonnam National Univ, 77 Yongbongro, Gwangju, 61186, South Korea.
authors.forename: Jae-Hak
authors.initials: JH
authors.lastname: Moon
mesh_terms: D001713:Biphenyl Compounds / Q000378:metabolism; D005285:Fermentation; D005419:Flavonoids; D044948:Flavonols / Q000032:analysis / Q000494:pharmacology; D005511:Food Handling / Q000379:methods*; D005960:Glucosides / Q000032:analysis / Q000494:pharmacology*; D006801:Humans; D000070007:Leuconostoc mesenteroides / Q000201:enzymology / Q000378:metabolism*; D019697:Onions / Q000737:chemistry*; D010084:Oxidation-Reduction; D010851:Picrates / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology; D011794:Quercetin / Q000031:analogs & derivatives / Q000032:analysis / Q000494:pharmacology*; D012965:Sodium Chloride; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D001713:Biphenyl Compounds; D005419:Flavonoids; D044948:Flavonols; D005960:Glucosides; D010851:Picrates; D010936:Plant Extracts; C047368:3-methylquercetin; D012965:Sodium Chloride; D011794:Quercetin; C432511:isorhamnetin 3-O-glucoside; C004931:1,1-diphenyl-2-picrylhydrazyl; D001617:beta-Glucosidase; C110309:quercetin 3-O-glucopyranoside
keywords: Leuconostoc mesenteroides; NaCl; antioxidative activity; onion; β-glucosidase