Enhancement of antioxidant activity of onion powders by browning during drying process

Dong Jin Lee, Jung Ah Han, Seung Taik Lim

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Drying process was applied to increase the antioxidant activity of onion powder: freeze-drying or air-drying at 50, 70, and 90°C and onion extracts were obtained from each powder using water or aqueous ethanol (50%) at 25°C and 60°C. In the color analysis, the freeze-dried powders showed higher L and lower a and b values than did the air-dried ones. The browning index of powders air-dried at 90°C was significantly higher than that of freeze-dried powders or those air-dried at temperatures below 90°C. Phenolic content in the extracts was 4.02-23.12 mg gallic acid equivalent/g sample, and was the highest in the extract from the sample air-dried at 90°C, regardless of the extraction condition. The highest antioxidant activity, measured by 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and 1,1-diphenyl-2-picrylhydrazyl methods, was found in the powder air-dried at 90°C, which induced browning. These findings indicate that antioxidant activity depends more on browning during drying than on extraction conditions.

Original languageEnglish
Pages (from-to)15-19
Number of pages5
JournalKorean Journal of Food Science and Technology
Issue number1
Publication statusPublished - 2016 Feb 1


  • Air-drying
  • Antioxidant activity
  • Browning index
  • Onion powder
  • Phenolic content

ASJC Scopus subject areas

  • Food Science
  • Biotechnology
  • Applied Microbiology and Biotechnology


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