Evaluation of the contribution of skatole, indole, androstenone and androstenols to boar-taint in back fat of pigs by HPLC and capillary gas chromatography (CGC)

Fifteen samples of fat with boar taint were selected by means of a trained panel-test, from 200 carcasses of entire male pigs, and they were analyzed to determine skatole, indole, 5-Androst-16-en-3-one (5-An), 5-Androst-16-en-3-ol (5An3) and 5-Androst-16-en-3β-ol (5An3β).

The extraction was carried out with methanol, the extract was placed at −20°C during 10 min to eliminate the fat and after evaporation of methanol a Florisil clean up was applied to obtain skatole and indole in a separate fraction from 5An and androstenols.

Skatole and indole were determined by HPLC in normal phase with a Spherisorb-NH₂ column and 5An and androstenols were analyzed by capillary gas chromatography (CGC). Selective procedures were used for detection: ratio at 220 nm and 280 nm (skatole/indole) and CGC coupled to a mass spectrometer working in the SIM (selected ion monitoring) mode at m/z 272 (o5An) and m/z 274 (androstenols). The results obtained showed that skatole and 5An concentrations exceeded that typical thresholds values in more than 50% of samples analyzed, suggesting a similar influence on boar taint. 5An3β showed higher concentrations than 5An3, but lower than 5An, exceeding only 1·00 μg/g in three samples.