Lipid oxidation and changes in the phenolic profile of watercress (Nasturtium officinale L.) leaves during frying

Alam Zeb*, Asia Habib

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Watercress leaves were fried in sunflower oil and analysed for lipid oxidation and phenolic compounds by high-performance liquid chromatography with diode array detection (HPLC–DAD). Results revealed that total phenolic contents and radical scavenging activity decreased significantly at the initial stages and were stable in frying oil, indicating stability of frying oil. A significant increase occurred in chlorophylls of watercress leaves and frying oil. HPLC chromatograms showed a total of 12 phenolic compounds containing caftaric acid (17.3–31.8 µg/g), sinapic acid derivative (11.2–14.4 µg/g), 4-O-caffeoylquinic acid (9.98–12.8 µg/g), 4-O-feruloyl quinic acid (8.47–13.4 µg/g), caffeoyl feruloyl quinic acid (7.31–11.7 µg/g) and 5-O-caffeoylquinic acid (3.73–6.51 µg/g) as major compounds. A significant increase in the caffeic acid, caffeoyl hexose, chlorogenic acid, caftaric acid, coumaric acid derivatives and 3, 4-di-O-caffeoylquinic acid was observed, while a decrease occurred in Sinapic acid derivative, 5-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 4-O-feruloyl quinic acid and caffeoyl feruloyl quinic acid. Frying of watercress leaves increase the bioavailability of medicinally important phenolic compounds and also help to stabilise the frying oil.

Original languageEnglish
Pages (from-to)2677-2684
Number of pages8
JournalJournal of Food Measurement and Characterization
Issue number4
Publication statusPublished - 1 Dec 2018


  • Frying
  • HPLC
  • Leafy vegetables
  • Lipid oxidation
  • Phenolic compounds
  • Watercress

ASJC Scopus subject areas

  • Food Science
  • Chemical Engineering(all)
  • Safety, Risk, Reliability and Quality
  • Industrial and Manufacturing Engineering

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