Germ fighter cuts the mustard

(Edmonton) Mustard—it’s not just for hotdogs anymore.

University of Alberta researcher Christina Engels has discovered how to extract a compound from mustard seeds that can protect against food spoilage.

Engels recovered a particular compound—sinapic acid—from mustard seed meal, which shows antibacterial effects against such strains as Staphylococcus aureus, E. coli and Listeria monocytogenes, all of which can cause grave illness and death in humans.

The results published recently in the journal, European Food Research & Technology.

The mustard family includes black, brown, Oriental, white and yellow varieties. Canada is the world’s largest exporter of mustard seed, with 90 per cent of those crops grown in Saskatchewan.

Engels’ isolation of sinapic acid lends a useful function to mustard seed meal, which is the product left over after the seed is pressed for its oil. While the oil can be used in making biodiesel and in some Asian markets as cooking oil, “the defatted seed meal left over is currently of little economic value,” said Engels, who conducted the research to complete her PhD in the U of A Department of Agricultural, Food and Nutritional Science.

There are several plant extracts that have a wide range of bioactivities, “but the challenge is to determine which of the many compounds in the extract is the active compound,” Engels said. She was able to do just that with mustard seed meal, using a strong lye to break complex components down and isolate just the sinapic acid.

Since most companies don’t have the intricate technology required to sort through the many compounds in plant extracts, the discovery makes it possible to quantify the bioactivity of the extracts with standard instrumentation.

“That means the mustard seed meal can be used as a source for natural food preservatives,” Engels said, and could mean more consumer choice. “If there are consumers out there who want natural products, this would give them that option.”

Engels’ latest work with mustard seeds builds on research she’s been conducting throughout her time as a U of A student. Intrigued by the idea of unlocking the beneficial qualities of plant extracts, she earned her master’s degree at the U of A in 2009, basing it on research of the mango kernel.

Through that project and her subsequent doctoral studies, she found a way to turn the throwaway kernels into a natural food preservative that could help prevent listeriosis outbreaks in humans.

She believes plant extracts offer huge potential for health benefits related to their antimicrobial, anti-inflammatory and antioxidant qualities.

“Mother Nature holds all these great bioactivities ready and all we need to do is find ways to make them work for us.”

Engels’ research was funded by the National Sciences and Engineering Research Council of Canada and by the Canada Research Chair Program.