Effects of irradiation and fumigation on the antioxidative properties of some spices

The effects of gamma irradiation (5.6 kGy) and ethylene oxide fumigation on the antioxidative activity of marjoram, nutmeg, paprika and black pepper were investigated. Sunflower oil in water emulsion (1:1), dark, at 30 deg C, lard, dark, at 40 deg C, lard, illuminated, at 50 deg C, and lard, dark, at 50 deg C were the substrates utilized for the investigation. Oxidation of the substrates in the presence of 0.2% (by weight) of spices were followed by the determination of peroxide value (PO) and free fatty acide value (FFA). No significant effect of irradiation on the antioxidant activities of spices was revealed. Fumigated marjoram tended to be less antioxidative in lard kept in dark storage at 60 deg C than the non-treated or irradiated spice. Marjoram and nutmeg lost their antioxidant properties in the presence of light. This loss, however, was not influenced by the irradiation or fumigation treatments. (author)