Fatty acid composition and measurement (cholesterol oxides, fluorescent products and TBA value) of lipid oxidation in raw and cooked white and dark chicken meat during 5-6°C storage

Chicken meat, white and dark, was treated with (1) salt, (2) phosphate, and (3) phosphate + antioxidant (rosemary oleoresin) while raw and then cooked and stored 0, 5, and 10 days at 5-6°C. The moisture, total lipid content, fatty acid composition of the total lipids, level of cholesterol (CHOL), 7-α-hydroxycholesterol (ALPHA), 7-β-hydroxycholesterol (BETA), 7-ketocholesterol (KETO) and 3 polar, lipid soluble, fluorescent products, and the 2-thiobarbituric acid (TBA) value were determined in the meats. Compared with white meat, dark meat had less moisture (69.5 versus 66.6%), more lipid (13.76 versus 5.87%), lower concentrations of polyunsaturated fatty acids (22:5 and 22:6) and ALPHA (0.27 versus 0.85 μg/100 g meat) and higher CHOL (73 versus 43 mg/100 g meat), and KETO (5.8 versus 3.4 μg/100 g meat) levels.

Meat containing treatments of phosphate resulted in increased levels of moisture, and generally, in decreased oxidation during 10 days of 5-6°C storage. Levels of linoleic (18:2) and arachidonic acids decreased during cooking and with increasing storage of the chicken meats. In meat receiving salt treatment, levels of KETO and one fluorescent product increased and increasing storage time. TBA value also increased with increasing storage time of salt treated white meat and up to 5 days storage of salt treated dark meat. The TBA value was correlated (p<0.05) with concentrations of 18:2 (r=-0.54) and KETO (r=0.47). In combination with TBA value, KETO level may be an additional indicator of lipid oxidation in stored, cooked poultry meat.