DETECTION AND QUANTIFICATION OF PHOSPHOLIPID HYDROPEROXIDES IN TURKEYMEAT EXTRACTS BY PLANAR CHROMATOGRAPHY

HPTLC and scanning densitometry have been used for detection and quant ification of phospholipid hydroperoxides as primary oxidation products in cooked turkey meat, The meat was treated with antioxidants (200 pp m ascorbyl palmitate or with 200 ppm ascorbyl palmitate pins 200 ppm n atural tocopherols) and its oxidative deterioration at 4 degrees C was followed for nine days. Total lipids extracted by the Folch method we re separated into their phospholipid classes on silica gel HPTLC plate s. A phospholipid-hydroperoxide-specific reagent, N, N-dimethyl-p-phen ylenediamine, and a charring reagent, cupric sulfate-phosphoric acid, were used separately to detect and identify phospholipid hydroperoxide s and their parent lipid classes. Calibration curves for the quantitat ive determination of phospholipid hydroperoxides were obtained for eac h chromatogram using 80-1200 ng cumene hydroperoxide as an external st andard, Phospholipid hydroperoxide levels were expressed as ng cumene hydroperoxide equivalents g(-1) sample. The results demonstrated that the initial levels of phospholipid hydroperoxides were markedly increa sed in meat samples containing exogenous antioxidants in comparison wi th the controls (no additives), In all samples the initial levels of p hospholipid hydroneroxides showed a time-dependent decrease, Thus the antioxidants seemed to stabilize the initial level of phospholipid hyd roperoxides and to retard their decomposition. This innovative method could be useful for indicating the oxidative stability of cooked meat.