title: Antiradical capacity and polyphenol composition of asparagus spears varieties cultivated under different sunlight conditions.
abstract: BACKGROUND
  Asparagus officinalis has a high nutritional value. Asparagus is rich in a number of bioactive compounds, mainly flavonoids (quercetin), glutathione, vitamin C, vitamin E, fructans (inulin and fructooligosaccharides) and phytosterols (b-sitosterol). These compounds may play an important role in human health. The purpose of this study was to examine the antioxidant potential and polyphenol composition of white, pale-colored and green asparagus spears of different cultivars.
  
  
  METHODS
  Investigations were conducted on different asparagus spear extracts. The study included three colors of asparagus (white, pale-colored and green) from five different cultivars subjected to the ethanol extraction procedure. Total phenolic content was also determined by the Folin-Ciocalteu method. Polyphenol (phenolic acids and flavonols) composition was estimated using the HPLC method. The antioxidant properties of extracts were examined using DPPH, ABTS and metal ion chelating assays.
  
  
  RESULTS
  The highest contents of phenolic and flavonoids were observed in green asparagus from Grolim and the lowest in pale-colored asparagus from Gyjmlin. It was found that both the color of asparagus and the cultivar had a significant effect on the composition of phenolic acid and flavonols. Radical scavenging activity toward DPPH• and ABTS was highest for green asparagus cv. Grolim and Eposs. The greatest number of Fe ions was chelated by samples of green asparagus cv. Grolim and Huchel's Alpha and pale-colored asparagus cv. Huchel's Alpha.
  
  
  CONCLUSIONS
  It was shown that the antioxidant activity of asparagus spears measured by antiradical and chelating activity test depends on variety and color. The highest activity was found in green asparagus and the lowest was identified in white asparagus extracts. It has also been clarified that changes in flavonol and phenolic acid composition and increases in their diversity depends on growing with sunlight and variety. Asparagus can provide a valuable source of phenolic compounds in the human diet.
authors.affiliation: Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Kulczyński
authors.affiliation: Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kobus-Cisowska
authors.affiliation: Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland.
authors.forename: Dominik
authors.initials: D
authors.lastname: Kmiecik
authors.affiliation: Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Gramza-Michałowska
authors.affiliation: Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Golczak
authors.affiliation: Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Poland.
authors.forename: Józef
authors.initials: J
authors.lastname: Korczak
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D001205:Ascorbic Acid / Q000032:analysis; D027761:Asparagus Plant / Q000737:chemistry* / Q000254:growth & development; D052160:Benzothiazoles / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis; D044948:Flavonols / Q000032:analysis; D005630:Fructans / Q000032:analysis; D005978:Glutathione / Q000032:analysis; D062385:Hydroxybenzoates / Q000032:analysis; D007444:Inulin / Q000032:analysis; D009844:Oligosaccharides / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis; D059808:Polyphenols / Q000032:analysis*; D011794:Quercetin / Q000032:analysis; D012855:Sitosterols / Q000032:analysis; D013451:Sulfonic Acids / Q000032:analysis; D013472:Sunlight; D014810:Vitamin E / Q000032:analysis
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D005419:Flavonoids; D044948:Flavonols; D005630:Fructans; D062385:Hydroxybenzoates; D009844:Oligosaccharides; D010936:Plant Extracts; D059808:Polyphenols; D012855:Sitosterols; D013451:Sulfonic Acids; C116580:fructooligosaccharide; D014810:Vitamin E; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C025473:gamma-sitosterol; D007444:Inulin; D011794:Quercetin; D005978:Glutathione; C017616:phenolic acid; D001205:Ascorbic Acid
keywords: antioxidant activity; antiradical properties; asparagus; bioactive compounds; polyphenols