Improvement of Peroxyl Radical Scavenging Bioassay Based on Bactericidal Action of tert-Butyl Peroxyl Radical

Abstract

  An improved bioassay for measurement of peroxyl radical scavenging activity^1,2) is described. The modifications included the use of (1) Enterococcus faecium strain S, (2) 25% dimethyl sulfoxide, (3) L-ascorbic acid for the termination of the bactericidal reaction, and (4) the concentration of antioxidants that gives 75% of the log (colony forming unit/ml) of the control reaction (without methemoglobin or tert-butyl hydroperoxide), for the expression of antioxidant activity.