Free radical scavenging properties of wheat extracts.
Three hard winter wheat varieties (Akron, Trego, and Platte) were examined and compared for their free radical scavenging properties and total phenolic contents (TPC). Free radical scavenging properties of wheat grain extracts were evaluated by spectrophotometric and electron spin resonance (ESR) spectrometry methods against stable 2,2-diphenyl-1-picryhydrazyl radical (DPPH*) and radical cation ABTS*+ (2,2'-azino-di[3-ethylbenzthiazoline sulfonate]). The results showed that the three wheat extracts differed in their capacities to quench or inhibit DPPH* and ABTS*+. Akron showed the greatest activity to quench DPPH radicals, while Platte had the highest capacity against ABTS*+. The ED50 values of wheat extracts against DPPH radicals were 0.60 mg/mL for Akron, 7.1 mg/mL for Trego, and 0.95 mg/mL for Platte under the experimental conditions. The trolox equivalents against ABTS*+ were 1.31 +/- 0.44, 1.08 +/- 0.05, and 1.91 +/- 0.06 micromol/g of grain for Akron, Trego, and Platte wheat, respectively. ESR results confirmed that wheat extracts directly reacted with and quenched free radicals. The TPC were 487.9 +/- 927.8 microg gallic acid equivalents/g of grain. No correlation was observed between TPC and radical scavenging capacities for DPPH* and ABTS*+ (p = 0.15 and p > 0.5, respectively).
Yu
Liangli
L
Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, Colorado 80523, USA. yu@cahs.colorado.edu
Haley
Scott
S
Perret
Jonathan
J
Harris
Mary
M
Wilson
John
J
Qian
Ming
M
D052160:Benzothiazoles; D015764:Bepridil / Q000031:analogs & derivatives*; D001713:Biphenyl Compounds; D002412:Cations; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers; D005609:Free Radicals; D005707:Gallic Acid / Q000032:analysis; D007700:Kinetics; D010636:Phenols / Q000032:analysis; D010851:Picrates; D010936:Plant Extracts / Q000737:chemistry*; D013045:Species Specificity; D013451:Sulfonic Acids; D014908:Triticum / Q000737:chemistry*
D052160:Benzothiazoles; D001713:Biphenyl Compounds; D002412:Cations; D016166:Free Radical Scavengers; D005609:Free Radicals; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D005707:Gallic Acid; D015764:Bepridil; C004931:1,1-diphenyl-2-picrylhydrazyl