TBA Values and 7‐Ketocholesterol in Refrigerated Raw and Cooked Ground Beef

Thiobarbituric acid (TBA) values and 7‐ketocholesterol were determined on raw and cooked ground beef patties after 0, 2, and 4 days of storage at 4°C. The mean 7‐ketocholesterol at days 0, 2, and 4 was 9.65, 23.8, and 42.3 μg for 100g raw patties and 6.33, 277.9, and 484.7 kg for 100g cooked patties. The TBA values increased after 2 and 4 days for the raw and cooked patties. TBA values and 7‐ketocholesterol were correlated with each other for raw (r 2 = 0.82) and cooked (r 2 = 0.98) patties. The peak suspected to be 7‐ketocholesterol was confirmed by mass spectral analysis. The 7‐ketocholesterol in the cooked patties stored two days represented a 0.3% oxidation of the free cholesterol.