THE PROBLEM OF TAINT IN PORK .1. DETECTION THRESHOLDS AND ODOR PROFILES OF ANDROSTENONE AND SKATOLE IN A MODEL SYSTEM

Detection thresholds of androstenone and skatole were established usin g a trained 10-member sensory panel. Odour profiles for these compound s were also developed using a model system comprising a lipid base spi ked with synthetic androstenone and skatole. A total of 2160 presentat ions were used for the determination of sensory thresholds which were obtained using the Ascending Method of Limits with a 3-AFC (Alternate Forced Choice) mode of presentation. Preliminary odour profiles were o btained bit three consensus-profiling sessions. Character notes develo ped were then validated by profiling four classes of model samples con taining androstenone, skatole, a mixture of skatole plus androstenone and a mixture of skatole plus androstenone plus indole. Individual sen sory thresholds for the ten panel members varied between 0.2 to 1.0 mu g g(-1) for androstenone and 0.008 to 0.06 mu g g(-1) for skatole, le nding to group thresholds of 0.426 mu g g(-1) and 0.026 mu g g(-1) for androstenone and skatole, respectively. The important descriptors for the odour of androstenone included, sweaty, ammonia, dirty, parsnip, silage, nosefeel and acrid. Among these, only the sweaty note was foun d to be a significant (p < 0.05) basis for separating pure samples of androstenone from pure samples of skatole by the panel. The important descriptors for the odour of skatole were; mothball, musty and body re action. Both the mothball and musty notes were a significant (p < 0.00 1 to p < 0.05) basis for distinguishing between either pure samples of skatole or mixtures containing skatole from pure samples of androsten one. The results show that androstenone and skatole are synergistic, b ut only in relation to the descriptors defining intensity of the odour s, and not in those defining the character of their individual odours. (C) 1997 Elsevier Science Ltd.