Agricultural, Food and Nutritional Science Professor Michael Gӓnzle and fellow researchers at the University of Alberta have developed a new set of food preservative agents which are naturally derived.

Food today is often prepared more by its processors than consumers, such as luncheon meats and microwaveable dinners. More convenient foods are stocking grocery shelves, and ready-to-eat items are growing in prominence.

“Most of the stuff which [was] done by the household 50 years ago is now done by the food industry,” Gӓnzle said. “Which means that less food items, [and] meals, are prepared from scratch.”

As the role of the processor grows, so do concerns about food safety, as highlighted by the listeria outbreak in Maple Leaf products last year, for example. Concerns about the health risks of inorganic preservatives and heightened awareness of food-borne illnesses is powering new outlooks in food safety.

“You can control much of the [disease-causing bacteria] by chemical preservatives. For ready-to-eat meats, you can add sodium lactate and sodium diacetate. [It] doesn’t make your food taste any better,” Gӓnzle said.

Interest in more organic and natural alternatives to chemicals is driving research. Gӓnzle’s research involves two different groups of compounds: the bacteriocins and polyphenols, and their anti-microbial properties.

Bacteriocins are compounds that are produced by lactic acid bacteria, such as lactobacillus reuteri. These bacteria are involved in pickling and other traditional preserves. Bacteriocins have been found to be as effective as inorganic additives in controlling germs like listeria, without altering flavour and being easy to utilize. Gӓnzle’s research focused on specific bacteriocins, determining their potency and mode of action.

“You take what is there naturally and you try to fortify it,” Gӓnzle noted.

However, Gӓnzle discovered that germs such as E. coli and salmonella are not affected; their structure makes bacteriocins ineffective. But combinations with other methods, like high-pressure treatment for meat, make bacteriocins effective against these germs too. Bacteriocins in this combination were also found to be more effective at eradicating harmful bacteria than chemical agents. Prepared foods like salads and cold cut meats are most likely to apply this technology; its utilization as of yet is not widespread.

Gӓnzle has also done research on polyphenols derived from plants, specifically gallotannins. Plants produce a variety of anti-microbial agents, like polyphenols, which can be isolated and potentially used in food. Researchers with Gӓnzle, demonstrated that polyphenols from mango kernels have an ability to inhibit pathogens; however, how they work is unclear for now.

“A mode of action for polyphenols can differ quite substantially. We don’t know yet the effectiveness of polyphenols,” noted Gӓnzle.

In addition, factors in the system, like iron, can inhibit the potency of some polyphenols. Polyphenols, though, can be applied to more types of foods and are effective against a wider range of germs. Meat and dairy are likely candidates for their application, though it isn’t ready yet.

With consumers demanding a challenging medley of safe, convenient, affordable, and healthy foods, processors must be on the cutting edge of innovation. Researchers see the potential for natural preservatives as a win-win situation for both consumers and producers.

Brent Puchalski, News Writer