Quick-test identifies compounds that can give pork an unpleasant smell

Maria DNA3

Prof. Maria DeRosa, Carleton University

By Lilian Schaer for AgInnovation Ontario

Ottawa – A new tool being developed at Carleton University will be able to quickly and easily identify the presence of two compounds in pork that can give the meat an unpleasant odour when it’s cooked.

In the pig business, this smell is called “boar taint”, and stems from two compounds, skatole and androstenone, found in uncastrated or intact male pigs.

Currently, to avoid the potential of boar taint, most farmers castrate male piglets at a very young age. It’s labour intensive for farmers and stressful for the animals, so the industry has long been searching for options to keep bacon and other pork products tasting great.

Dr. Maria DeRosa, in the university’s chemistry department, is developing a tool similar to a pregnancy test used in women that allows for detection of the two compounds either in live animals or in a carcass at processing.

“We need to know what the levels of the compounds in pigs are that will cause boar taint. The current way of having people sniff for boar taint is both subjective and expensive,” she explains. “So is there a way to measure these compounds cheaply and easily? Can we detect them in fat, for example?”

One current alternative to conventional castration is immunocastration, which means vaccinating the animals to try to keep the two compounds from developing as the pigs hit puberty.

And a team of Canadian researchers is working on a identifying the appropriate genetic markers in hopes of breeding pigs where boar taint won’t be an issue.

DeRosa’s solution involves a biosensor that uses aptamers – small, single-stranded nucleic acids that can bind to large or small target molecules. They’re the “keys” to identifying which DNA sequences will bind to target molecules.

She and her research team are identifying the aptamers that will bind to skatole and androstenone, and are working to have them packaged into a small test kit that can provide results very quickly and without needing to send samples to a lab for testing.

“Our pregnancy test-style kit changes colour if either of these compounds is present in the meat. For example, we can biopsy a small bit of fat from a live animal, and if skatole is found, the aptamer will “grab” it and the test will indicate its presence,” she says.

This could help farmers with breeding, allowing them to select animals that naturally have low enough levels of these compounds so they won’t result in boar taint when pork is cooked. It could also help identify animals at processing whose meat may develop the smell.

DeRosa’s work has received support from Growing Forward 2, a federal-provincial-territorial initiative, through the AgriInnovation Program, and from the Natural Sciences and Engineering Research Council.