## 2 Materials and Methods
### Thiobarbituric Acid Reactive Substances (TBARS), Hydroperoxides and Protein Carbonyls Analyses  
Raw minced samples (5 g) were placed in a 50-mL test tube and homogenized with 15 mL deionized distilled water (DDW). Homogenate (1 mL) was transferred to a glass tube for the TBARS determination and 0.05 mL of butylated hydroxytlouene (7.2% in ethanol) was added along with 1.950 mL of thiobarbituric acid (TBA)/trichloroacetic acid (TCA)/HCl (0.375% TBA, 15% TCA, and 0.25 N HCl). The sample solution was shaken and then incubated at 90 \({}^{\circ}\)C for 15 min. in a thermostatic bath. After this period, the samples were cooled to room temperature (15-30 \({}^{\circ}\)C) and then centrifuged at 2000\(\times\) g for 15 min. Supernatant absorbance at 531 nm was measured against a blank containing 2 mL of TBA/TCA/HCl solution in 1 mL of distilled water. The TBARS were calculated when comparing with a standard curve constructed with 1,1,3,3-tetramethyl-thermostyp propane, and the concentration of lipid oxidation was expressed as milligrams of malondialdehydedehyde (MDA) per kg of meat [35].  
For hydroperoxides quantification, 2 mL of homogenate (previously prepared for the TBARS determination) were added with 4 mL of CH\({}_{3}\)OH and 2 mL of CHCl\({}_{3}\). The samples were vortexed for 30 s and added with 2 mL of CHCl\({}_{3}\) and 1.6 mL of 0.9% NaCl. The samples were shaken for 1 min. and then centrifuged at 3500\(\times\) g for 10 min. at 4 \({}^{\circ}\)C. Two millilitres of lipid extract were sampled from the lower chloroform phase and then processed with 1 mL of CH\({}_{3}\)COOH/CHCl\({}_{3}\) and 50 \(\mu\)L of KI (1.2 g/L mL distilled water). Samples were stored for 5 min. in a dark room and added with 3 mL of 0.5% of CH\({}_{3}\)COOCd and then vortexed and centrifuged at 4500\(\times\) g for 10 min. at 40 \({}^{\circ}\)C. Absorbance at 353 nm was measured against a blank tube in which meat homogenate was replaced by 2 mL of distilled water [36]. The results were expressed in micromoles per gram according to [PERSON] and Aust [35].  
Meat samples (2 g) were homogenized in 20 mL of 0.15 M KCl for 2 min. Two aliquots of homogenate (50 \(\mu\)L each) were added with 1 mL 10% TCA and then centrifuged at 1200\(\times\) g for 3 min. at 4 \({}^{\circ}\)C to measure protein oxidation. The first aliquot was used as a standard and added with 1 mL of 2 M HCl solution. The second aliquot was added with 1 mL of 2 M HCl containing 10 mM 2,4-dinitrophenyl hydrazine (DNPH). The samples were incubated for 1 h at room temperature (15 to 30 \({}^{\circ}\)C) and shaken every 20 min., and then 1 mL of 10% TCA was added. The samples were vortexed for 30 s and centrifuged three times at 1200\(\times\) g for 3 min. at 4 \({}^{\circ}\)C and the supernatant removed. Care was taken not to disrupt the pellet. The pellet was washed with 1 mL of ethanol:ethyl acetate (1:1), shaken, and centrifuged three times at 1200\(\times\) g for 3 min. at 4 \({}^{\circ}\)C and the supernatant removed. The pellet was then dissolved in 1 mL 20 mM sodium phosphate 6 M guanidine hydrochloride buffer. The samples were then shaken and centrifuged at 1200\(\times\) g for 3 min. at 4 \({}^{\circ}\)C. Carbonyl concentration was calculated on the DNPH treated sample at 360 nm with a Beckman Coulter DU800 (Beckman Instruments Inc., Brea, CA, USA) and expressed as nanomoles carbonyl per milligrams protein. Protein concentration was calculated according to the Biuret assay [37,38].