Composition and Content of Flavonol Glycosides in Green Beans and Their Fate during Processing

Abstract

Four varieties of green bean (Phaseolus vulgaris) were analyzed for flavonol composition and content. Two flavonol conjugates, not previously reported in green bean, were found in three of the varieties. These are quercetin 3-O-(2G-β-d-xylopyranosylrutinoside) (1), (1.0−2.0 μg/g of fresh weight) and the corresponding kaempferol analogue (2) (0.3−0.7 μg/g). The major flavonol component in all of the varieties was quercetin 3-O-glucuronopyranoside (3) (3.5−15.1 μg/g) with lesser amounts of quercetin 3-O-rutinoside (4) (0.2−4.3 μg/g) and kaempferol 3-O-glucuronopyranoside (5) (0.5−1.3 μg/g). Kaempferol rutinoside (6) was detected in only one variety (0.8 μg/g). Commercial processing, such as canning, did not result in chemical breakdown of the conjugates, although between 8.8 and 24.4%, depending on the conjugate, was leached into the cooking water. Keywords: Phaseolus; green bean; HPLC; flavonol; glycoside

Effects of conventional boiling on the polyphenols and cell walls of pears

“…Boiling has been shown to induce flavonol losses of 20% and 40% in onions and asparagus, respectively. 21 Price et al 22 reported that canning did not result in chemical breakdown of flavonol glycosides but that leaching into cooking water was significant and depended on the conjugate. Cooking by boiling or frying of onions 23 led to a 25% loss of flavonol glycosides.…”

Absorption/Metabolism of Sulforaphane and Quercetin, and Regulation of Phase Ii Enzymes, in Human Jejunum in Vivo

“…Standards of quercetin glucuronides and of quercetin glucosides were either synthesized or extracted from plants as described previously (Price et al, 1998;Day et al, 2001). All polyphenolic standards were Ͼ97% pure; the identities, including position of attachment of the conjugate, have been determined using chemical synthesis and NMR (O'Leary et al, 2001).…”

Amentoflavone and Kaempferol Glycosides from the Aerial Parts of Cissampelos pareira

“…Three compounds (1-3) were isolated from the 70% MeOH extract by repeated column chromatography on MCI gel CHP20P, Sephadex LH20 and silica gel. The structures of these compounds were identified as amentoflavone [11], kaempferol 3-O--Dglucopyranoside [12] and kaempferol 3-O--Dglucuronopyranoside [13] (Figure 1) on the basis of NMR spectral data and comparison with reported values in literatures.…”