Skip to main content
padlock icon - secure page this page is secure

Effects of cultivar, lifting time and nitrogen fertiliser level on quercetin content in onion (Allium cepa L.) at lifting

The full text article is not available for purchase.

The publisher only permits individual articles to be downloaded by subscribers.

Commercial cultivars of onion (Allium cepa L.) were grown at Torslunda research station, Sweden with different levels of nitrogen fertiliser and lifted at different growth stages. Soon after lifting, before any drying or curing, tissue from the fleshy edible part of onions was extracted in ethanol and the raw extracts were analysed by high‐performance liquid chromatography without any previous hydrolysis. It was confirmed that the main flavonoid compounds were quercetin monoglucoside and quercetin diglucoside, whereas only trace amounts of quercetin aglycone and other flavonoids were found. The greatest variation in quercetin content, in the range 100–500 mg kg−1 fresh weight, occurred between years. The concentration of quercetin glucosides in the onions was strongly correlated (R 2 = 0.98) with the total amount of global radiation in August. Individual onions with fallen leaves had significantly higher concentrations of quercetin glucosides than individuals in the same row with erect leaves. Only minor differences were found between the three cultivars analysed. Higher levels of nitrogen fertiliser had only minor effects on onion yield and size and resulted in lower or equal amounts of quercetin glucosides. Nitrogen leakage from the soil, a potential source of environmental problems, could therefore be minimised by avoiding high nitrogen fertiliser levels with almost no effect on onion flavonol content. Late lifting of onions (80% fallen leaves) resulted in up to 45% higher concentrations of quercetin glucosides compared with early lifting (50% fallen leaves). Copyright © 2006 Society of Chemical Industry
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Allium cepa; cultivar; lifting time; nitrogen fertiliser; onion; quercetin glucoside

Document Type: Research Article

Publication date: 01 February 2007

More about this publication?
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more