The effects of autoclaving and filter sterilization on the recovery of butylated hydroxyanisole, butylated hydroxytoluene, tertiary butylhydroquinone, and propyl gallate in laboratory media were investigated by a nonderivatizing gas chromatography-mass spectrometry (GC-MS) method. Lauryl tryptose broth (LTB) or brain heart infusion (BHI) broth were treated with the combinations of the phenolic antioxidants at 200 ppm. The antioxidants were dissolved in 95% ethanol and either added directly to the media followed by autoclaving or filter-sterilized and then added to sterilized media in a flask. Results suggested that antioxidant recoveries were affected by the modes of sterilization as well as by the complexity of the medium. More antioxidants were recovered from the filter-sterilized than from the autoclave-sterilized samples for LTB medium, but no clear difference was seen for BHI broth. The recovery was lowest with butylated hydroxytoluene regardless of medium type or sterilization mode used. The extraction procedure applied as well as the nonderivatizing GC-MS method appeared to be adequate for the simultaneous determination of the four antioxidants.
† Present address: Department of Food Science and Toxicology, University of Idaho, Moscow, ID 83844-2201, USA.
‡ Contribution no. 96-225-J from Kansas Agricultural Experiment Station.