The aim of the work was to develop a simple method to detect boar tainted carcasses at the slaughter line. This was done by uncover practical issues regarding the human nose method: “hot water” and hereafter validate the method.
Materials and Methods
The hot water method is simple: lard cut in medium size pieces are added to a 100 mL conical flask and 75 mL boiling hot water are poured over the lard. The flask are “closed” with tinfoil and left standing for 2 min. before detection. Validation was carried out as series of individual studies and included: 1) Optimal amount of lard, 2) optimal temperature at assessment, 3) manageable number of samples pr. day including method flexibility and 4) Assessor sensitivity.
The optimal amount of lard is approx. 5 g. Lower levels (1 g) generated only a faint odor, difficult to assess, and higher amounts did not improve odor intensity. A temperature at approx. 80°C seemed optimal as the sample was hot but steam did not hurt the nose. It was possible to assess 200 samples in one working day (7.5 h). However, it will demand two people to handle all the samples. Assessor sensitivity did not change during the 200 samples.
During the work it became apparent that androstenone is the more difficult compound of the two (skatol and androstenone) and that great care must be taken in order to screen and train the assessors properly.
It is sometimes said that organic boars contain boar taint at a higher intensity level compared with conventional boars, presumably because the organic boars typically are older when slaughtered. The panel therefore tested approx. 40 organic boars and 40 conventional boars – and there was no apparent intensity difference between the two groups of boars.
The combination of temperature, at the time of assessment, and the amount of lard used pr. sample is crucial for the intensity of boar taint. It is practically possible to handle 200 samples in one working day, and this number of samples does not change the sensitivity of the assessors. The samples can be prepared and left standing in the fridge (5°C) for up till 5 days. Careful screening of assessor sensitivity towards androstenone is of outmost importance.