2.6. TBARS and FRAP
The antioxidant capacity of the diets is shown in Table 2.
At the beginning of the fattening period, 10 animals were randomly
sampled for blood plasma. Ten animals of each treatment were sampled
at the end of this period. The samples were centrifuged at 3500 rpm for
10 min at 4 ◦C, plasma was deposited in cryostat tubes and stored in liquid
nitrogen at −196 ◦C until analysis.
The antioxidant capacity of the plasma was measured using the
FRAP technique by Benzie and Strain (1996). The pattern curves were
done with different trolox (6-hydroxy-2-5-7-8-tetramethylchroman-2carboxylic acid) concentrations, which is a water soluble equivalent of
vitamin E.
TBARS (thiobarbituric acid reactive substances) analysis was done
according to the technique described by Ohkawa et al. (1979). The samples were read in a Thermo Scientific UV-V15 spectrophotometer. Sample
analyses were carried out twice. The results were interpreted as MDA,
which is a by-product of lipid peroxidation.
2.7. Statistical analysis
A completely random design with three treatments was used. Data
were analyzed by analysis of variance, for DWG, FI and FC; initial weight
was used as covariable in the following model: