Lipid oxidation
Lipid oxidation was measured by the 2-thiobarbituric acid method of Pfalzgraf et al. [7]. The
TBA-reactive substances (TBARS) values were calculated from a standard curve of
malondialdehyde, and expressed as mg malondialdehyde/kg sample.
Intramuscular fat and fatty acid analysis
Intramuscular fat (IMF) was extracted from the muscle according to the Bligh & Dyer [8]
method and quantified as the weight percentage of wet muscle tissue. The samples were
extracted according to [8] to determinate composition in fatty acids from intramuscular fat
and the methyl esters from fatty acids (FAMES) were analysed in a gas chromatograph HP-
6890 II, with a capillary column SP-2380 (100 m x 0.25 mm x 0.20 μm), using nitrogen as
the carrier gas.
Statistical analysis
All data were statistically analysed by the general linear model (GLM) procedure of IBM SPSS
version 19 (IBM SPSS, 2010). The model included dietary fat supplementation and frozen
2
storage duration as main effects and also their interaction. However, only the results related to
the effect of frozen storage duration were presented when the interaction was not significant.
Duncan's post hoc test was used to assess differences between mean values when P≤0.05.