Abstract
Benzoyl peroxide bleach, added to cheese, is estimated by gas chromatographic determination of benzoic acid, its principal reduction product. Copper is added to the acidified ether extract of the cheese to reduce the residual bleach, and solvent partitioning and permanganate treatment are used for purification. The benzoic acid is transferred to chloroform containing lauric acid as an internal standard and determined by flame ionization gas chromatography, with a column containing 5% FFAP + 0.5% H3PO4 on Chromosorb W. The average recovery of added benzoyl peroxide was 82.0% and the standard deviation was 0.0128. The occurrence of benzoic acid of microbial origin in cheese poses a problem in accurately determining added benzoyl peroxide from the benzoic acid found in a sample.
