Screening methods to measure antioxidant activity of sorghum (sorghum bicolor) and sorghum products.

Specialty sorghums, their brans, and baked and extruded products were analyzed for antioxidant activity using three methods: oxygen radical absorbance capacity (ORAC), 2,2'-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH). All sorghum samples were also analyzed for phenolic contents. Both ABTS and DPPH correlated highly with ORAC (R(2) = 0.99 and 0.97, respectively, n = 18). Phenol contents of the sorghums correlated highly with their antioxidant activity measured by the three methods (R(2) >or= 0.96). The ABTS and DPPH methods, which are more cost effective and simpler, were demonstrated to have similar predictive power as ORAC on sorghum antioxidant activity. There is a need to standardize these methods to allow for data comparisons across laboratories.

[1]  W. Z. Kaluza,et al.  Separation of phenolics of Sorghum bicolor (L.) Moench grain. , 1980 .

[2]  L. Rooney,et al.  Sorghum phenolic acids, their high performance liquid chromatography separation and their relation to fungal resistance , 1983 .

[3]  L. Rooney,et al.  Tannins and phenols of sorghum , 1984 .

[4]  R. Bandyopadhyay,et al.  Polyphenol concentrations in grain, leaf, and callus tissues of mold-susceptible and mold-resistant sorghum cultivars , 1986 .

[5]  R. Waniska,et al.  Effects of growth conditions on grain molding and phenols in sorghum caryopsis , 1989 .

[6]  H. Alessio,et al.  Oxygen-radical absorbance capacity assay for antioxidants. , 1993, Free radical biology & medicine.

[7]  A. Waterhouse,et al.  Principal Phenolic Phytochemicals in Selected California Wines and Their Antioxidant Activity in Inhibiting Oxidation of Human Low-Density Lipoproteins , 1995 .

[8]  C. Berset,et al.  Use of a Free Radical Method to Evaluate Antioxidant Activity , 1995 .

[9]  T. Chandra,et al.  ESR spectroscopic studies on free radical quenching action of finger millet (Eleusine coracana) , 1996 .

[10]  R. Prior,et al.  Antioxidant Capacity of Tea and Common Vegetables , 1996 .

[11]  P. Pietta,et al.  Polyphenol Content and Total Antioxidant Potential of Selected Italian Wines , 1997 .

[12]  C. Rice-Evans,et al.  Factors influencing the antioxidant activity determined by the ABTS.+ radical cation assay. , 1997, Free radical research.

[13]  C. Berset,et al.  Kinetics and Mechanisms of Antioxidant Activity using the DPPH.Free Radical Method , 1997 .

[14]  G. Jones,et al.  High Molecular Weight Plant Polyphenolics (Tannins) as Biological Antioxidants. , 1998, Journal of agricultural and food chemistry.

[15]  J. Vervoort,et al.  TEAC antioxidant activity of 4-hydroxybenzoates. , 1999, Free radical biology & medicine.

[16]  M. B. Arnao,et al.  Methods to measure the antioxidant activity in plant material. A comparative discussion. , 1999, Free radical research.

[17]  C. Fraga,et al.  Influence of oligomer chain length on the antioxidant activity of procyanidins. , 2000, Biochemical and biophysical research communications.

[18]  G. Mazza,et al.  Assessing antioxidant and prooxidant activities of phenolic compounds. , 2000, Journal of agricultural and food chemistry.

[19]  M. Peyrat-Maillard,et al.  Determination of the antioxidant activity of phenolic compounds by coulometric detection. , 2000, Talanta.

[20]  K. Stettmaier,et al.  Electron paramagnetic resonance studies of radical species of proanthocyanidins and gallate esters. , 2000, Archives of biochemistry and biophysics.

[21]  M. B. Arnao,et al.  Some methodological problems in the determination of antioxidant activity using chromogen radicals : a practical case , 2000 .

[22]  F. Shahidi,et al.  Scavenging of reactive-oxygen species and DPPH free radicals by extracts of borage and evening primrose meals , 2000 .

[23]  R. Prior,et al.  Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe. , 2001, Journal of agricultural and food chemistry.

[24]  I. Rietjens,et al.  The influence of pH on antioxidant properties and the mechanism of antioxidant action of hydroxyflavones. , 2001, Free radical biology & medicine.

[25]  R. Prior,et al.  Measurement of Total Antioxidant Capacity in Nutritional and Clinical Studies , 2001 .

[26]  R. Wrolstad,et al.  Anthocyanins, phenolics, and antioxidant capacity in diverse small fruits: vaccinium, rubus, and ribes. , 2002, Journal of agricultural and food chemistry.

[27]  G. Shui,et al.  An investigation of antioxidant capacity of fruits in Singapore markets , 2002 .

[28]  Dejian Huang,et al.  Analysis of antioxidant activities of common vegetables employing oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays: a comparative study. , 2002, Journal of agricultural and food chemistry.

[29]  G. Beecher,et al.  Fractionation of polymeric procyanidins from lowbush blueberry and quantification of procyanidins in selected foods with an optimized normal-phase HPLC-MS fluorescent detection method. , 2002, Journal of agricultural and food chemistry.

[30]  C. Rice-Evans,et al.  The Antioxidant Activity of Regularly Consumed Fruit and Vegetables Reflects their Phenolic and Vitamin C Composition , 2002, Free radical research.

[31]  M. Manley,et al.  Antioxidant activity of South African red and white cultivar wines: free radical scavenging. , 2003, Journal of agricultural and food chemistry.