Rapid Estimation of Hydrogen Peroxide in Milk by the Use of Guaiac Test Solution

Abstract

Gum guaiac solution is easily oxidized by hydrogen peroxide in the presence of peroxidase to develop a blue color that has its absorbance maximum at 610nm. A linear calibration curve was obtained up to an hydrogen peroxide content of 0.25-2.0μg. We attempted to apply this phenomenon to the rapid estimation of hydrogen peroxide in milk. When milk was dialyzed against 10 volumes of 0.05% potassium bromate, it was possible to detect not less than 0.25ppm of hydrogen peroxide in the milk, the recovery at the 1ppm spikage level being 64.2%. Though we also attempted to apply the guaiacol test to the detection of hydrogen peroxide in milk, this test was relatively ineffective compared with the guaiac test. The established method was applied to the inspection of residual hydrogen peroxide in commercial milks sold in the Osaka area in polyethylene-coated paper cartons. All the samples were confirmed to be free from hydrogen peroxide.