title: Evaluation of Antioxidant Activity ofR. Slooffiae,R. MucilaginosaExtracts.
abstract: BACKGROUND
  Antioxidants are health beneficial compounds that can protect cells and macromolecules from the damage of reactive oxygen species (ROS). The aims of this study were to compare the total antioxidant and carotenoid production inR. SlooffiaeandR. Mucilaginosa.
  
  
  METHODS
  To isolate the carotenoid pigment, cells were suspended in acetone and broken using a homogenizer, followed by centrifugation, and supernatant was separated. For analytical method, pigments were measured spectrophotometrically at 450 nm. The B-carotene bleaching and 1, 1-diphenyl-2-picrylhdrazyl (DPPH) assay were used to determine antioxidant properties ofR. SlooffiaeandR. Mucilaginosaby measuring the decrease in absorbance at 470 and 517 nm.
  
  
  RESULTS
  The results showed that the content of total carotenoid inR. Slooffiaewas higher thanR. Mucilaginosaand it presented higher ability to show antioxidant activity. The mean total antioxidant activity of ascorbic acid was the highest (97.11 ± 6.11%), followed by BHT (64.71 ± 5.41%), R. sloofias extract (57.91 ± 7.34%) andR. Mucilaginosa(39.32 ± 5.85%). The EC50 of ascorbic acid was the strongest (0.252 ± 0.000 mg/ml), followed by BHT (0.612 ± 0.009 mg/ml) andR. Slooffiae(0.658 ± 0.033 mg/ml). There was significant difference observed between the EC50 ofR. Slooffiaeand BHT.
  
  
  CONCLUSIONS
  It was found that both strains have ability to produce carotenoid and show antioxidant ability; however,R. Slooffiaehad more potential in producing carotenoid and showing antioxidant ability thanR. Mucilaginosa. Further study is required, in order to utilize this strain in the food, pharmaceuticals and cosmetics industries.
authors.affiliation: Ph.D., Associate Professor, Department of Biotechnology, Faculty of Biological Science, Alzahra University, Tehran, Iran.
authors.forename: Parichehr
authors.initials: P
authors.lastname: Hanachi
authors.affiliation: Faculty of Biological Science, Alzahra University, Tehran, Iran.
authors.forename: Farzaneh Sadat
authors.initials: FS
authors.lastname: Naghavi
keywords: Antioxidant; Carotenoid; Radical scavenging activity; Rhodotorula