2.3 | Analysis of the fatty acid composition
FA composition of freeze-dried LD muscle samples was quantified using
Agilent 6890 gas chromatography mass spectrometry (GC/MS) (Agilent
Technologies Inc., Wilmington, DE). The FAs were methylated with acetyl
chloride/methanol (1:10, v/v), and
hendecanoic
acid methyl ester (C11:0) was used as an internal standard (1mg
ml-1). The DB-23 column (60 m × 0.25 mm, film
thickness 0.25 μm) temperature was held at 130°C for 1 min and then was
increased to 260°C at a rate of 4°C min-1.
Subsequently, the injector and detector (FID) temperatures were set at
270°C, and the helium flow ratio was 2 ml min-1. An
automatic split injector was used with a ratio 30:1. By comparing the
retention times of the individual FA peaks with the known standards (37
component FAME mixture), the fatty acids could be identified.