Total Quercetin Content in Onion: Survey of Cultivars Grown at Various Locations

Abstract

<jats:p>Because of potential benefits on human health, the content of quercetin, the major flavonol found in onion (<jats:italic>Allium cepa</jats:italic>), could become a selection trait in breeding programs. Total flavonol concentration in onion was examined by spectrophotometric analysis at 374 nm in three long-day hybrid cultivars grown at three locations (Parma, Idaho; Grand Rapids, Mich; Elba, N.Y.), and in three shortday hybrid cultivars grown at one location in Georgia in three different fields. Mean total flavonol concentrations for long-day hybrids ranged from 176 to 232 mg·kg<jats:sup>-1</jats:sup> (ppm) fresh weight and 110 to 173 mg·kg<jats:sup>-1</jats:sup> fresh weight among short-day cultivars. No significant effect of location (state or field) was detected (<jats:italic>P</jats:italic> &gt; 0.05). A significant (<jats:italic>P</jats:italic> &gt; 0.05) cultivar by field interaction was detected in the short-day experiment, with the hybrid `Sweet Vidalia' showing significant differences among fields. Overall, our results suggest that quercetin content in onion, as expressed by the total flavonol content, does not vary depending on the growing origin, and therefore could be evaluated effectively in breeding or commercial material.</jats:p>

Nutritive Constituents of Onion Grown from Sets as Affected by Water Supply

“…In the present study, mean total flavonol content varied between 430 and 753 mg • kg -1 on a FW basis (Table 4). This level is comparable to previously reported results of yellow onions, ranging between 158 and 1187 mg • kg -1 on a FW basis (Lombard et al, 2004;Mogren et al, 2006;Slimestad et al, 2007), but it is considerably lower than total flavonol content of red onions (Pérez-Gregorio et al, 2010). Mean total polyphenol content varied between 607 and 1029 mg • kg -1 on a FW basis (Table 4).…”

Subcritical water extraction and β-glucosidase-catalyzed hydrolysis of quercetin glycosides in onion waste

“…Furthermore, several recent studies have shown that different types of natural polyphenols may have neuroprotective effects both in vitro and in vivo, 6-10 partly due to their electron scavenging properties. 14 Several research projects have undertaken the isolation and identification of quercetin and its glycosides in various fruits and vegetables, including onion, 15 kale, 16 broccoli, 17 apple skin, 18 green tea, 19 and grapes and wine. 8,[11][12][13] Quercetin is a polyphenolic compound that occurs in vegetables and fruits mainly as different glycosides, although the skin of the fruit/vegetable commonly contains higher amounts of the quercetin aglycone.…”

Flavonoids - From Biosynthesis to Human Health

“…The long-day cultivars from Northern Europe and their close relatives contain higher concentrations of quercetin glucosides than those of Japanese and North American. In long-day cultivars, total quercetin content was higher than in short-day cultivars being independent of the growing origin [51,52].…”