BOAR TAINT - ANALYTICAL ALTERNATIVES

Entire male pig production has gained considerably in interest during recent years. As a small percentage of tainted carcasses is observed, a prerequisite for a successful production is removal of these. Conseq uently several procedures for determination of boar taint were reporte d. In the present paper different analytical procedures are compared. In general they give identical results on identical samples, i.e. they are not plagued by systematical errors. The Danish colourimetric meth od yielding ''skatole equivalents'' shows a high correlation (>0.975) to results obtained for skatole With a HPLC procedure. An even higher correlation (r = 0.986) is obtained by including both skatole and indo le in the comparison, i.e. ''skatole equivalents'' have contributions from both compounds. The colourimetric method appears from an analytic al chemist's point of view rather simple; however, several apparently simple but devastating problems have been encountered, amongst which t he most critical were: purity of the acetone, procedure for preparatio n of the reagents and timing of the development of colour before spect rophotometric determination. Concerning androstenone analysis general consensus between the alternative procedures, comprising HPLC, GC-MS, RIA and ELISA methods, also exists. However, it was found that a comme rcial ELISA assay shows a number of outlier results. A sorting or cont rol procedure relying on a single ELISA result therefore seems rather hazardous, and at least duplicate analyses are recommended. The relati onship between skatole androstenone and smell mainly confirmed the pre vious results That is, 58 % of the variation in odour/flavour could be explained by the ''skatole equivalents''. By including androstenone t he explanation of the variation increased to about 66 %. Androstenone alone explained only about 24 %. The occurrence of falsely accepted Pi gs that have a deviating smell although accepted from an analytical po int of view, was investigated using a trained taste panel. If either 0 .25 ppm skatole equivalents or alternatively 0.5 Ppm androstenone is u sed as threshold limit, the present study on Danish Pigs shows that 1. 2 % of the approved male carcasses will have a deviating smell in both cases. However, androstenone analysis will sort out 48 % of all males , whereas ''skatole equivalents'' ''only'' removes 4.3 %.