title: Evaluation of antioxidant activity of three common potato (Solanum tuberosum) cultivars in Iran.
abstract: OBJECTIVE
  Potato (Solanum tuberosum L.), as a whole food, contains high levels of vitamins and important antioxidants including phenolic acids, carotenoids and flavonoids. The objective of this study was to determine the total phenolic content and antioxidant activities of three common potatoes (Solanum tuberosum) cultivars in Iran i.e., Savalan, Agria and Sante.
  
  
  METHODS
  Phenolic compound extraction of samples was done with methanol and total phenolic on the basis of folin-ciocalteu assay was estimated as 16.58 to 36.24 mg GAE/100g dry sample. The antioxidant activities of potato extracts on the basis of inhibition of linoleic acid peroxidation and DPPH assay were compared with a commercially available antioxidant, α -tocopherol.
  
  
  RESULTS
  Savalan had the highest phenolic content and the highest DPPH radical scavenging activity with EC50 value of 41.815±mg/ml (DB). Also Savalan had the best inhibitory action against linoleic acid oxidation at 94.10±1.89% at 50 mg/ml sample concentration. Methanolic potato extracts had better antioxidant activity than α-tocopherol. Significant (p<0.01) negative correlation was observed between total phenolic content and the EC50 for DPPH radical scavenging activity(R=-0.877), but there was no correlation between total phenolic content and total antioxidant activity.
  
  
  CONCLUSIONS
  Metanolic extracts of three potato cultivars are able to inhibit the oxidation process. The correlation between total phenolic content and DPPH radical scavenging activity indicates that phenolic compounds are responsible for antiradical activity.
authors: Faculty of Food Science, Islamic Azad University, Shahreza Branch, Isfahan, Shahreza, I. R. Iran.
authors: Faride
authors: F
authors: Hesam
authors: Department of Potato Research Biotechnology, University of Isfahan, I. R. Iran.
authors: Gholam Reza
authors: GR
authors: Balali
authors: Department of Potato Research Biotechnology, University of Isfahan, I. R. Iran.
authors: Reza Taheri
authors: RT
authors: Tehrani
keywords: Antioxidant activity; Potato; Radical scavenging; Total phenolic compounds