Comparison of the accuracies of chemical and sensory tests for detecting taint in pork

Chemical and sensory tests are widely used to detect boar taint in meat from entire male pigs. Chemical tests typically assess tissue levels of the compounds associated with taint, including 16-androstenes, like 5α-androstenone, and skatole. Sensory tests classify boar carcasses into either tainted or untainted categories according to test criteria assessed by human evaluators. The threshold levels of taint compounds are typically determined according to the results of chemical tests. This experiment was designed to compare chemical analyses and sensory tests by a trained panel for the determination of taint and to study their accuracies. Fat samples were taken in a slaughterhouse from 220 intact male pigs killed at 100.4 ± 0.4 kg body weight. Fat samples, frozen after collection at slaughter, were subsequently analyzed for levels of androstenone and skatole using a colorimetric method. Samples also were evaluated by a trained sensory panel for the presence of boar taint. Forty-nine percent of males had fat androstenone levels above 1.0 ppm, the cutoff level used to discriminate tainted from untainted pork. Only 2% of pigs had fat skatole levels above 0.25 ppm of cutoff level. Fifteen percent of boars were judged as tainted by the sensory panel. Based on the cutoff levels of 1.0 ppm of fat androstenone and 0.25 ppm of fat skatole, the sensitivities and specificities of the chemical analysis were, respectively, 100% and 54.1% for androstenone, and 8.0% and 99.0% for skatole. The sensitivity and specificity of pooled data (combined androstenone and skatole) were 84.8% and 57.2%, respectively; positive and negative predictive values were 25.9% and 95.5%, respectively. These results suggest that fat androstenone is more reliable than skatole for identifying taint. Furthermore, chemical analysis of tissue levels of androstenone and skatole does not identify all tainted carcasses, suggesting that other compounds may also contribute to taint.