The problem of taint in pork-II. The influence of skatole, androstenone and indole, Presented individually and in combination in a model lipid base, on odour perception

Responses to varying concentrations of androstenone and skatole in a neutral lipid base were studied using a trained 10-member panel. Concentrations for skatole and androstenone ranged between 0-1.32 and 0-6.0 μg g(-1), respectively. Odour, androstenone and skatole intensities were assessed by the line scaling method. Triangular tests showed that the panel significantly distinguished indole from androstenone, p ≤ 0.01, but not from skatole nor mixtures of androstenone and skatole. Regression analyses showed linear relationships between skatole and androstenone concentrations and odour intensity but with a significant (p ≤ 0.01) androstenone-assessor interaction. Correlation coefficients with odour intensity were 0.64 and 0.63 for androstenone and skatole concentrations, respectively. Response surface curves showed that odour intensity depended on the linear terms of skatole, androstenone and on the quadratic term of androstenone. Androstenone and skatole intensity ratings revealed that the effect of skatole was enhanced by the presence of androstenone, but not the reverse. It was concluded that whilst both androstenone and skatole may be important for the sorting (classification) of pork, the importance of androstenone lies in its detection threshold whilst for skatole, the acceptability threshold may be a suitable criterion for quality control purposes.