Lab News

Peeling back the cancer-fighting potential of Ontario-grown onions


By Jane Robinson - Ag Innovation Ontario  (Link

Guelph – There’s a new reason to cry when you peel back the layers on a local Ontario onion in your kitchen…tears of joy, that is.

New research at the University of Guelph has found a way to safely extract the free-radical fighting properties of Ontario-grown onions, creating new opportunities for Ontario farmers and the nutraceutical and food production industries.

In the not-so-distant future, you could be enjoying the healthy properties of onions through supplements, additives and creams.

Scientist have long known that onions carry the highest content of quercetin (an antioxidant flavonoid) of nearly 40 different fruits and vegetables. Flavonoids like quercetin attract and neutralize free radicals – the naturally-occurring molecules in human tissue that can lead to cancerous cells.

Suresh Neethirajan, a bioengineering researcher in the School of Engineering at the University of Guelph, is in the final phase of an Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) funded project examining the varying levels of quercetin in Ontario-grown onions.

Suresh Neethirajan

“This is the first study that’s looked specifically at the 17 or 18 major varieties of onions grown in Ontario to determine if the level of flavonoids varies among varieties,” says Neethirajan.

After extracting flavonoids from the Ontario onion varieties using a new water-based extraction technology developed in Neethirajan’s lab, there was a clear winner.

“We put the onion flavonoids in direct contact with human breast and colon cancer cells, and measured the rate of apoptosis (cancer cell death) among the different varieties. Red onions have a four-fold increase in the ability to trigger cancer cell death compared to any other variety,” he says.

For Ontario onion growers, the news gets even better.

“Onions grown in Ontario, especially in the Holland Marsh, are able to retain more nutrients and antioxidants,” Neethirajan says, attributing this largely to good management practices and soil type.

With the strong demand for antioxidant nutraceuticals, Neethirajan sees potential for a new high-value crop potential for farmers and a residue-free, onion-based antioxidant for manufacturers.

“We want farmers to know what manufacturers might be looking for, so they can be ready with sufficient supply,” he says.

The extraction process removes most of the onion smell and taste, opening options for adding the substance to drinks, bakery items, encapsulating in a pill form, and even skin-based products.

“Now that we have developed a new, safer protocol for extracting flavonoids from onions, and scientifically verified the activity on breast and colon cancer cells, the next step is to look at economical ways to produce and manufacture products with onion-extracted flavonoids,” he says.

And if you’re wondering if you could just add more raw onion to your diet for the same healthful effect, it’s not that simple.

Neethirajan says you’d need to eat a few kilograms of raw onion a day to realize the potential cancer-fighting effects from onion flavonoids, compared to levels concentrated through the extraction process.

Bionanolab research results on the development of novel biosensors has been published in high impact journals namely the prestigious Royal Society of Chemistry's Nanoscale journal and the Chemical Communications Journal. 

A highly efficient 2D exfoliated metal dichalcogenide for the on-farm rapid monitoring of non-esterified fatty acids

Satish K. Tuteja and Suresh Neethirajan 

Chemical Communications, 2017, 53, 10002 - 10005   (Link

We report on the development of an electrochemically active liquid exfoliated 2D MoS2 nanosheet based biointerface for the on-farm monitoring of non-esterified fatty acid (NEFA) biomarkers


Liquid exfoliation of 2D MoS2 nanosheets and their utilization as a label-free electrochemical immunoassay for subclinical ketosis




On August 9th, 2017 - Ryan Berthelot - member of the Bionano research team successfully defended his master's thesis. 

Ryan's thesis was titled 'Electrotaxis and Electrical Property Quantification of Pathogenic Bacteria Using Microfluidics and Nanoscale Imaging'. 

Ryan's successful defense exam was celebrated at the Brass Taps Pub on August 9th with lunch party. 

L to R: Ryan Berthelot, Amit Tah, Connor Ormbsy, John Buozis, Jack Mogus, Xuan Weng, Rohit Chand, Rahin Ahmed, Satish Tuteja, Meghan Fragis, Abdul Murayyan, Gordon Hayward, Suresh Neethirajan 

The Canadian Organic Grower – Canada’s Organic Farming and Gardening Magazine conducted and published an interview with Prof. Neethirajan in their summer magazine Summer 2017. The interview can be found here in the link.  The interview is titled ‘The Onion Comes of Age: Pizza Topper, Salad Zinger, and Cancer Fighter’.

University of Guelph’s professor Dr. Suresh Neethirajan has been elected as incoming president of the Canadian Society for Bioengineering (CSBE). Dr. Neethirajan will take up the post of CSBE president-elect on August 9, 2017, followed by a one-year term as CSBE president beginning July 2018.

A registered Professional Engineer with the province of Ontario, Dr. Neethirajan has received several awards at the national and global level for research excellence. He is the 2015 Young Engineer of the Year recipient of Engineers Canada and the 2015 Young Engineering Achievement award winner by both the Canadian and the NABEC section of the American Society for Agricultural and Biological Engineers. He also was the recipient of the Japan Society for the Promotion of Science fellowship and the Alexander-von Humboldt fellowship of Germany in 2009.

Dr. Neethirajan’s research goals include development of biosensors and bioinstrumentation tools and techniques for solving problems in the agri-food and animal health systems using bionanotechnology approaches. Neethirajan has previously served as Vice-President (Technical) on the Society’s executive board and governing council and was chair of the Emerging Technologies Committee of the American Society of Agricultural and Biological Engineers. Neethirajan also currently serves as an Associate Editor for the CSBE’s flagship journal – the Canadian Journal of Biosystems Engineering.

As president, Neethirajan will act as the chief officer and official representative of CSBE. Founded in 1958, CSBE - the Canadian Society for Bioengineering seeks to advance and develop agricultural and biological engineering principles for the production of food, bio-products, animal health and bio-energy. With several thousand members and affiliated with over 20 Canadian Universities, the society holds workshops and meetings, as well as public information and education programs.


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Bionanotechnology Laboratory
Suresh Neethirajan

School of Engineering
University of Guelph
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Room 3513 - Richards Building
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Lab: THRN 2133 BioNano Lab

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