JSR Genetics introduced its first ever Student Press Release Competition last year, tempting students with the opportunity to present their work at a special event linked to the company's 19th Technical Conference, entitled '50 Years of Excellence in Breeding'.

The initiative was set up to help talented, skilled individuals to enter the pig industry. The competition brought two winners, one of whom was Claudia Richards. She is a qualified vet who completed her first degree at the University of San Marcos in Lima in Peru, and went on to undertake a Masters degree in Meat Science and Technology at Bristol University.

"My project involves the measurement of boar taint compounds in pork fat and the use of a sensory panel to assess any abnormal odour that the public would find unacceptable," Ms Richards explained. "I am working towards establishing the levels of boar taint compounds that allow separation between tainted and untainted carcasses."

In the study, she investigated the relationship between the concentrations of boar taint compounds, skatole and androstenone, in the adipose tissue (fat) and how these impact sensory scores for pork and abnormal odours.

A total of 50 fat samples were taken from entire male pigs at a commercial farm. The samples were analysed for skatole and androstenone, and also subjected to sensory analysis.

For skatole, most of the samples were contained less than 1.0 µg per gramme of fat although there were two outliers, which had much higher levels of between 2.0 and 2.5 µg skatole per gramme.

For androstenone, the majority of the samples were in the range 0.4 to 1.5 µg per gramme of adipose tissue, with three outliers in the range 2.0 to 3.0 µg per g.

The samples were then subjected to sensory analysis and given scores for pork odour and abnormal odour. The results are shown in the table below. Each sample was classified into one of four groups: high or low skatole (HS and LS, respectively, more than and less than 0.2 µg per g fat) and high or low androstenone (HA and LA, respectively, more than and less than 1.0 µg per g of fat).

The results showed that pork odour was not related to the two boar taint compounds. However, abnormal odour was affected by skatole content of the fat, with the high skatole (HS) groups giving significantly higher scores for abnormal odour in the sensory test than LS, independent of the androstenone level.

Ms Richards proposed that a rough threshold value for abnormal odour – at a score of 5, which is 'slightly strong' – equates to a 0.5 µg skatole per gramme of fat.

March 2009